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brad1138
07-25-2010, 07:11 PM
I just replaced my Athena C1 (http://www.athenaspeakers.com/products/c1-overview/) center with 2 Athena S1 (http://www.athenaspeakers.com/products/s1-overview/)'s. The C1 is basically a S1 with a passive radiator. I have 1 S1 upright below the TV and the other upside down above it. My wife has my camera and is out of town or I would post pictures of the way I mounted the top S1. I am running both S1's in parallel off my Marantz MA-500 mono amp. Other than the obvious benifit of the vocals coming from the TV rather than below it, they come across more powerful and more full, giving the effect of a much larger spk, I am really pleased with the results. The S1's were just sitting around not being used anyway. The S1's tweeter is aimed slightly up (5-10 degrees?) which works well for this setup in that the tweet aims toward the listener from both "center" spks.

Anyway, I am glad I decided to do this and would recommend it to anyone else.

Brad

Sir Terrence the Terrible
07-25-2010, 07:43 PM
I just replaced my Athena C1 (http://www.athenaspeakers.com/products/c1-overview/) center with 2 Athena S1 (http://www.athenaspeakers.com/products/s1-overview/)'s. The C1 is basically a S1 with a passive radiator. I have 1 S1 upright below the TV and the other upside down above it. My wife has my camera and is out of town or I would post pictures of the way I mounted the top S1. I am running both S1's in parallel off my Marantz MA-500 mono amp. Other than the obvious benifit of the vocals coming from the TV rather than below it, they come across more powerful and more full, giving the effect of a much larger spk, I am really pleased with the results. The S1's were just sitting around not being used anyway. The S1's tweeter is aimed slightly up (5-10 degrees?) which works well for this setup in that the tweet aims toward the listener from both "center" spks.

Anyway, I am glad I decided to do this and would recommend it to anyone else.

Brad

Brad,
You may have convinced yourself it sounds good, but this really is a bad practice and I don't care how well it is done. Either you are hearing the effect of frequency combining, or you are hearing the tweeters cancelling, but there is no way this kind of setup is even close to flat. If you drop two rocks side by side in a pond, and watch the waves come together, that is what your set up is doing. When those waves meet, depending on the wavelength and frequency, they will either be is phase and boost the output at those frequencies, or they will be out of phase and cancel some frequencies. Either way this venture veers away from a flat frequency response, and depending on where you sit in the room, you will hear different tonalities and timbres coming from this setup.

Not recommended at all.

PeruvianSkies
07-25-2010, 07:53 PM
I just replaced my Athena C1 (http://www.athenaspeakers.com/products/c1-overview/) center with 2 Athena S1 (http://www.athenaspeakers.com/products/s1-overview/)'s. The C1 is basically a S1 with a passive radiator. I have 1 S1 upright below the TV and the other upside down above it. My wife has my camera and is out of town or I would post pictures of the way I mounted the top S1. I am running both S1's in parallel off my Marantz MA-500 mono amp. Other than the obvious benifit of the vocals coming from the TV rather than below it, they come across more powerful and more full, giving the effect of a much larger spk, I am really pleased with the results. The S1's were just sitting around not being used anyway. The S1's tweeter is aimed slightly up (5-10 degrees?) which works well for this setup in that the tweet aims toward the listener from both "center" spks.

Anyway, I am glad I decided to do this and would recommend it to anyone else.

Brad


This is the type of rubbish that confuses those who are new to this hobby and have little time to really investigate the proper ways to utilize their home theater.

Obviously using two speakers will have a fuller sound than just one, it should produce twice the sound, but that's not really the point here. The center channel should in in balance with the left and right, which takes calibration time to adjust.

More importantly, it could cause overload on the receiver depending on how this is hooked up since most receivers or amps only have outputs for 1 center channel.

Newbies beware.

brad1138
07-25-2010, 08:45 PM
This is the type of rubbish that confuses those who are new to this hobby and have little time to really investigate the proper ways to utilize their home theater.

Obviously using two speakers will have a fuller sound than just one, it should produce twice the sound, but that's not really the point here. The center channel should in in balance with the left and right, which takes calibration time to adjust.

More importantly, it could cause overload on the receiver depending on how this is hooked up since most receivers or amps only have outputs for 1 center channel.

Newbies beware.

First of all, I adjust volume levels with an SPL meter and set them in 1/2 dB increments with my Lexicon Pre amp. My Marantz MA-500 is 4 ohm stable and runs them fine. When listening the sound, primarily vocals, come from the center of the screen.

The same argument trying to be made against it could be made against using two speakers for mono playback (say an old Beatles CD) or even Stereo playback for anyone not sitting dead center. I have Googled a bit on it and found arguments for and against it. But don't tell me that my post is complete rubbish because you don't agree with it. I have a very nice system and a fairly critical ear, this works great for me.

As I walk around my (or anyones) room while listening to stereo music, I don't get a horrible (or any) oscillation as the L & R tweeters move in and out of phase w/each other. I don't think your argument holds much water.

Brad

Mr Peabody
07-25-2010, 09:09 PM
I have heard arguments for two centers before as well but never really researched it. it would seem two centers would more focus the sound from center screen, a stronger image than just one below or above. Having two centers could also help balance out only having a bad placement option, like too far above or below the screen. I thought that was well thought out pointing the top center firing the tweeter downward.

Like frequencies do increase but that would be minimized by recalibrating. Not sure what effect another center would have on overall frequency response, the only way to know for sure is to measure before and after for comparison. Wonder if any one has done that and put it into print?

Some receivers actually have outputs for two center channels, not the norm, but I have seen them. You can come off a center pre out with a "Y" adaptor into a stereo amp and easily hook up two centers. Just one of a few safe options.

PeruvianSkies
07-25-2010, 09:16 PM
First of all, I adjust volume levels with an SPL meter and set them in 1/2 dB increments with my Lexicon Pre amp. My Marantz MA-500 is 4 ohm stable and runs them fine. When listening the sound, primarily vocals, come from the center of the screen.

The same argument trying to be made against it could be made against using two speakers for mono playback (say an old Beatles CD) or even Stereo playback for anyone not sitting dead center. I have Googled a bit on it and found arguments for and against it. But don't tell me that my post is complete rubbish because you don't agree with it. I have a very nice system and a fairly critical ear, this works great for me.

As I walk around my (or anyones) room while listening to stereo music, I don't get a horrible (or any) oscillation as the L & R tweeters move in and out of phase w/each other. I don't think your argument holds much water.

Brad

You are comparing too many different things. First, most people don't walk around aimlessly while listening to music, if you are setting up a room to fill the room with sound from a variety of spots, there are other methods that can be used to decrease any type of phasing.

Most people (at least here) watch movies or listen to music in a dedicated spot, and the soundfield should not be that far off-center if you have things properly setup with a 5.1 or even 6.1/7.1 setup. A proper 2.0 stereo system with excellent speakers will give the illusion that sound is coming from all over to begin with, most notibly it will not sound like sound is coming from left or right, but the center field will be filled based on the recordings intentions and will be three-dimensional in width, height, and depth.

The only time that I could see using more than 1 center speaker would be in a theater system like a movie house with a huge screen and a room that is large enough to house 20 or more people.

luvtolisten
07-26-2010, 03:23 AM
Hi Brad, nice system you have there.Sounds like you're happy with it and that's all that matters. Since you are the one, who did the actual experiment, and just didn't go by theory, it holds more credibility with me. If you had a not so good system, an all in one Walmart special, I would question it, but that's definitely not the case here. We all hear and perceive things differently. And where &how we listen to them differently too.Otherwise, we'd all be sitting around with the same exact system. I applaud you for experimenting and sharing your results.
The only thing I would caution you on, is the impedance factor, (I'm assuming you have your centers in parallel, therefore cutting your impedance in half) be sure your amp can handle it and not cause any damage to it, should you decide to crank it. Enjoy!!

Mr Peabody
07-26-2010, 05:37 AM
I found this link, the writer talks about the parallel effect I unknowing described in my former post. He does say dual centers would be for larger screens or projection screens.
http://www.axiomaudio.com/tips_center_channel_sound.html

Most drawbacks I've read about seem tey could be taken away by calibrating, ie. level, delay.

I do have to add top/bottom dual centers I think can work in certainsituations but a beside the TV placement would defintely be a no no.

Sir Terrence the Terrible
07-26-2010, 01:08 PM
I found this link, the writer talks about the parallel effect I unknowing described in my former post. He does say dual centers would be for larger screens or projection screens.
http://www.axiomaudio.com/tips_center_channel_sound.html

Most drawbacks I've read about seem tey could be taken away by calibrating, ie. level, delay.

I do have to add top/bottom dual centers I think can work in certainsituations but a beside the TV placement would defintely be a no no.

First, you cannot correct the negative acoustical effects of using dual center speakers with calibration. It is an acoustical issue caused by two acoustical waves interacting with each other to produce complimentary and negative reflections.

Top and bottom, side by side setups both produce the same effects on different planes, but the end effect is exactly the same - nonuniformity in the propagation of the frontal wave.

Mr Peabody
07-26-2010, 01:18 PM
Sir T, I hear what you are saying but isn't dual centers basically the same effect asrear speakers? Especially in the day of Pro Logic.

Sir Terrence the Terrible
07-26-2010, 01:18 PM
First of all, I adjust volume levels with an SPL meter and set them in 1/2 dB increments with my Lexicon Pre amp. My Marantz MA-500 is 4 ohm stable and runs them fine. When listening the sound, primarily vocals, come from the center of the screen.

As it should.


The same argument trying to be made against it could be made against using two speakers for mono playback (say an old Beatles CD) or even Stereo playback for anyone not sitting dead center. I have Googled a bit on it and found arguments for and against it. But don't tell me that my post is complete rubbish because you don't agree with it. I have a very nice system and a fairly critical ear, this works great for me.

The difference between what you are doing, and what is done on a Beatles recording is the Beatles recording uses eq, and you are not. Secondly, if you measured the response of those two mono sources hitting your ears at identical arrival times, you would see both cancellation and reinforcemant of certain frequencies over others. Down the center, you would notice a profound notch at 2-4khz. Move your head to the left or right, and the notch disappears.

I can always convince myself that something sounds good, but can I convince others that it does?


As I walk around my (or anyones) room while listening to stereo music, I don't get a horrible (or any) oscillation as the L & R tweeters move in and out of phase w/each other. I don't think your argument holds much water.

Brad

You are listening to the wrong thing. Listen to the bass, and you will get a much different result.

If you are looking for better listening room coverage, you choose a loudspeaker with a wider dispersion pattern, not another speaker. If you are looking for more power, you choose a speaker with larger drivers or one with more drivers covering the individual frequencies. You don't get another speaker.

Sir Terrence the Terrible
07-26-2010, 01:27 PM
Sir T, I hear what you are saying but isn't dual centers basically the same effect asrear speakers? Especially in the day of Pro Logic.

The requirement for the rear channels in the prologic days was diffusion. In the front of the room it is directivity. All you get with two front center speakers is an uneven frequency response, and a equally poor coverage.

kelsci
07-26-2010, 03:12 PM
I tried two W-T-W center channels one on top of the other and I did not like the sound. The two speakers wire wired in parallel.

The second thing to take into account is the internal wiring scheme of center channel speakers. I am talking about the W-T-W design. I have noticed that some come with the two woofers rated each at 12 to 16 ohms wired in parallel giving you and impedance of 6-8 ohms. The other type appears to be two 3 to 4 ohm speakers wired in SERIES giving you 6 to 8ohms impedance. I would think that the latter might cause the two woofers cones to "fight" each other causing them to not properly work in phase with the rest of a 5.1 channel system. The former two wired parallel speakers are in-phase with each other and to me appears to blend with the rest of a 5.1 system. The wiring scheme of the latter system is similar to wiring for a passive surround system. Is that what one wants for their center channel sound? How does one know that they are getting from any manufacturer if they getting the former or the latter whether you look at it or even take an ohm meter to measure the DC resistance. I can tell you this that my parallel unit is not going anywhere unless I am dead. Now for those who have a 6.1 system, the series unit might be the speaker to use for the ES/EX sound. I just have a theory that it might work well but I have never been able to try it. Somebody out there might want to try it provided they know that their unit is one of those series units.

brad1138
07-26-2010, 09:55 PM
I have been very busy and don't have time for a full reply, but I will say that the the center chan amp I am using is THX cert and handles 4 ohm load w/o any trouble. Rated at 125 @ 8 ohms & 200 @ 4 ohms.

brad1138
07-27-2010, 07:18 PM
You are comparing too many different things. First, most people don't walk around aimlessly while listening to music.

You really missed the point. I never said I wander around aimlessly listening to music (a.h.) If you can move across your room while listening to 2 stereo speakers and the sound doesn't change much, then the same thing should be the case if your ears are not exactly between the 2 center speaker, it just so happens that in my set up my ears are within a couple inches of dead center between the 2. the difference in distance between the 2 is negligible.


A proper 2.0 stereo system with excellent speakers will give the illusion that sound is coming from all over to begin with, most notibly it will not sound like sound is coming from left or right, but the center field will be filled based on the recordings intentions and will be three-dimensional in width, height, and depth.

I am fully aware of that, my Mirage M3-SIs are a great imaging speaker that completely vanish, if you close you eyes you couldn't even point them out. They are a StereoPhile Class B speaker.


You are listening to the wrong thing. Listen to the bass, and you will get a much different result.

You are correct that bass varies as you move around the room, but I am not worried about bass from my center chans I have 2 subs that handle that. I have a 7.2 system.

I am not sure how you believe that there would be any hole if you are dead center between mono sources, the frequencies should match perfectly and there would be no cancellation.

I get the issues that 2 centers can create, I believe you guys are blowing them WAY out of proportion. The same issues that 2 centers can cause can be caused by the left and right speakers to anyone not sitting in the exact center. So I guess to make sure everything is just perfect, everyone should have there own individual home theater.

You are so quick to judge, and be rude about it. I am sure glad I shared my experience. Regardless of what you have to say, my ears will tell me what sounds good, not you.

Brad

P.S. luvtolisten and Mr Peabody, thank you for you comments. Also here (http://forums.audioholics.com/forums/showpost.php?p=701345&postcount=342) are pictures of my system/room, A few changes have been made since the pix, but they are listed in the Sig.

pixelthis
07-28-2010, 09:22 AM
Hate to agree with Talky on anything(you sure the world aint flat?) but hes' right in this case.
Get a really big honkin center , never use two unless its a large room and they are a good distance from each other, and then its a no alternative thing.:1:

pixelthis
07-28-2010, 09:28 AM
Hi Brad, nice system you have there.Sounds like you're happy with it and that's all that matters. Since you are the one, who did the actual experiment, and just didn't go by theory, it holds more credibility with me. If you had a not so good system, an all in one Walmart special, I would question it, but that's definitely not the case here. We all hear and perceive things differently. And where &how we listen to them differently too.Otherwise, we'd all be sitting around with the same exact system. I applaud you for experimenting and sharing your results.
The only thing I would caution you on, is the impedance factor, (I'm assuming you have your centers in parallel, therefore cutting your impedance in half) be sure your amp can handle it and not cause any damage to it, should you decide to crank it. Enjoy!!

Some aborigine tribes sacrifice virgins to a volcano, is that okay as long as they enjoy it?
A LOT of fender heads luv luv luv luuuv BOSE, doesnt change Bose's position as the
center of evil in the known world.
Point is, this freakin hobby is about accurate reproduction, or as close as you can get, and this person is missing out.
Big time.:1:

Sir Terrence the Terrible
07-28-2010, 10:57 AM
You really missed the point. I never said I wander around aimlessly listening to music (a.h.) If you can move across your room while listening to 2 stereo speakers and the sound doesn't change much, then the same thing should be the case if your ears are not exactly between the 2 center speaker, it just so happens that in my set up my ears are within a couple inches of dead center between the 2. the difference in distance between the 2 is negligible.

Here is where your logic fails you. Two stereo speaker will be reproducing two different signals with two different phase characteristic. Two speaker reproducing mono information is subject to almost totally cancellation between 2-4khz because of the HRT effect of both speakers output hitting the ear simultaneously. Now you can EQ this notch out, but then as you move off axis of center the sound will be much too bright. So you have narrowed your sweet spot substantially. Two woofers and two tweeter spaced apart will have driver interference issues that impact the frequency response of the signals themselves.



You are correct that bass varies as you move around the room, but I am not worried about bass from my center chans I have 2 subs that handle that. I have a 7.2 system.

Then you should be worried about frequencies from the crossover point of the subs and upward. There is no such thing as a 7.2 system, you only have one LFE channel. Just because two subs are reproducing it does not make another channel. The proper distinction would be a 7.1 system with two subs.


I am not sure how you believe that there would be any hole if you are dead center between mono sources, the frequencies should match perfectly and there would be no cancellation.

Its not a belief, its a fact. Have you ever heard of driver interference or lobing. This happens when two spaced drivers reproducing the same frequencies interfere with each other at certain frequencies. There is also comb filtering occurring as well.

http://www.integracoustics.com/MUG/MUG/articles/sources/

Go to the bottom of the page, and look at the moving example on the left


I get the issues that 2 centers can create, I believe you guys are blowing them WAY out of proportion.

I think because of your lack of knowledge of how the ear works you are underestimating the effects.


The same issues that 2 centers can cause can be caused by the left and right speakers to anyone not sitting in the exact center. So I guess to make sure everything is just perfect, everyone should have there own individual home theater.

The difference between left/right speakers and dual mono speakers lies in the fact the former is playing completely different information with different phase characteristic, and the latter plays the same mono signal with two speakers.

You are right, people should have their own hometheater systems, so they can make their own stupid mistakes, ignore good advice, and have a compromised system as a result.


You are so quick to judge, and be rude about it. I am sure glad I shared my experience. Regardless of what you have to say, my ears will tell me what sounds good, not you.

Brad

.

Brad, nobody is quick to judge anything. Do you really think you were the first person to think up this hair brained idea? No, you are not. I have seen these setup dozen of times, measured them, and showed the owners of these set ups the results. I disconnect one speaker, remeasured, and showed them the improvements. I am not a novice at these kinds of dumb set ups. If one is good, two must be better is a foolish concept when it comes reproducing mono signals.

If you think I am rude, I think your are stubbornly ignorant of a great many things when it comes to audio science. Now that we have voiced our opinions of one another, we can removed the personal issues out of the way, and deal with this bad idea.

Anyone can convince themselves that something is good if only to justify the reasoning for doing something.

Go to this page

http://www.falstad.com/ripple/

When the applet comes up, click on one source and look at the wave pattern. Now click on two sources, and see that wave pattern. The first has a nice clean wave, and the second with two sources shows considerable interference in the wave patterns. This is what is happen with you two center setup.

All one has to do is look at your setup, and you can see a bunch of problems with where the center are placed, along with the effects I have mentioned.

Mr Peabody
07-28-2010, 11:47 AM
Pix has escaped again! I haven't seen this many new posts since the last time he forgot his medication :) Maybe he was locked up for a while.

pixelthis
07-30-2010, 07:52 AM
Pix has escaped again! I haven't seen this many new posts since the last time he forgot his medication :) Maybe he was locked up for a while.

I decided that the world couldnt live without my brilliance.
Besides , somebodies gotta counter talky and his nonsense.
AND get the word out about Emotiva(audiophillia on the cheap).
And warn against buying plasma.
AND INVESTING IN 3d(MORE like 3 dead)
SO MANY LIES, SO LITTLE TIME....:1:

pixelthis
07-30-2010, 07:57 AM
And Polluted(er, peruvian) skies is back.
NO WONDER Dracula is his favorite movie, no matter how many times you stake him,
he still keeps on coming back, like the Energizer bunny, even having nothing to say
doesn't slow him down:1:

luvtolisten
07-30-2010, 08:49 AM
Some aborigine tribes sacrifice virgins to a volcano, is that okay as long as they enjoy it?
A LOT of fender heads luv luv luv luuuv BOSE, doesnt change Bose's position as the
center of evil in the known world.
Point is, this freakin hobby is about accurate reproduction, or as close as you can get, and this person is missing out.
Big time.:1:

Says YOU!!!
I would love to sacrifice a couple of virgins, are ya game?
http://www.youtube.com/watch?v=XRGd0gD0QNE&feature=related

Mr Peabody
07-30-2010, 08:59 AM
Just make sure they are virgins, any one see Jennifer's Body.....

brad1138
07-31-2010, 10:33 AM
There is no such thing as a 7.2 system

O...K... (http://www.yamaha.com/yec/technology/RelatedProducts.html?CNTID=202527) It's just semantics in the end, fine, 7.1 with 2 subs.

I found this post on a different forum, it really sums up, or puts into better words, the points I was trying to make:

Dick Pierce has been dispelling many audio myths on google groups rec.audio etc for the last couple decades. Makes for enjoyable reading.

When asked the same question about dual centers and comb filtering, here was his response.:


quote:
"The ONLY way possible to avoid comb filtering effects is to have a
single loudspeaker placed in an anechoic chamber.

As soon as you introduce multiple sources, whether real or virtual,
you WILL have comb filtering. (A "virtual" source is a reflection
of a real source. For example, place a loudspeaker 2 feet above the
floor: at frequencies where the floor is reflective, which is most
frequencies, there is an apparent or "virtual" source 2 feet BELOW
the floor, giving a doublet source with a separation of 4 feet).

That means that ALL stereo systems, ALL home theater system in ALL
rooms suffer from pretty massive amounts of comb filtering due to
path length differences to multiple coherent sources. It is completely
unavoidable in practice.

That being said, it can be argued that the more real sources you have,
especially sources that are placed different distances apart from room
boundaries and each other, the more evenly distributed the nulls of
the comb filtering will be and thus the smoother the overall response
due to comb filtering will be.

I think it can be argued, that, at its WORST, and additional center
channel speaker will NOT make things worse, and may potentially make
things better.

The arguments of the people you cite might be strictly true in a
first-order analysis but fail or at least loose much of their strength
when the entire boundary and multiple source considerations are taken.
One can further suggest that two competely coherent sources, placed
vertically, restrict radiation in the vertical plane, but not in the
horizontal plane, and thus can arguably REDUCE comb filtering effects
due to interference effects with the virtual sources under the floor
and above the ceiling.

Another point: the demon "comb filtering" itself is something of a red
herring in reality. Comb filtering can only occur if the size of the
radiating sources are very small compared to the wavelength while at
the same time the separation between them is large compared to the
wavelength. For something like the dual center-channel approach,
the ONLY frequencies where this is relevant is high frequencies, and,
within the listening window, the path length differences are simply
not big enough to cause the problem AND where they are big enough,
you're sufficiently far enough off axis that you don't care.

I believe the comb-filter argument against using dual center-channel speakers is specious and unsupportable."


I Googled "Dick Pierce" and found he is a long time professional in the audio industry, not just "some guy on a forum".

With obvious arguments on both sides, I believe this is opinion and not fact. My opinion is that done correctly, as I believe I have, it can work well.

We will just have to agree to disagree. You can feel whatever you want about me as I enjoy my HT.

Brad

P.S. My "rude" comment was referring mostly to "PeruvianSkies"

Dual-500
07-31-2010, 01:31 PM
A few decent replies and a lot of misplaced theory.

Never in the naysayers arguments did I see a hint of nearfield size and it's overall effect on reverberation control of the environment. EDIT: The post above is the real deal. :)

Having "Doubled up" so to speak on the centers has increased the near field radiation at the source.. Yea all the cancellations and other crap happens, but the room does a job on net performance anyway. We aren't listening in half space test lab, it's your viewing area. The overall performance of the environment is what really matters.

So, let's lighten a little on theoretical perfection. Comb filtering and it's effects are something to consider in design for sure. But not an absolute. If it were, the argument would render the very concept of STEREO OBSOLETE as well as center/right/left/rear/side.

Having increased the near field radiation will do a few beneficial things. The primary being the system will handle room reverberation better. i.e. standing waves. And, in a theatre system that's real important - the more standing waves in a given envrionment, the more it matters.

This is probably why you like the way it sounds.

With theatre the dynamic range on a peak to average is probably much wider than music would be. Lots of quieter vocal passages, so near field size at the source plays into the equation even more than with a pure music reproduction system. During the times when it's pure dialog from the center at mid to low levels, the ability of the system to control room reverberation is at it's lowest. Increasing this at the source, as you have done is the best soution.

Let me give you an example. Suppose we were to setup a PA in a typical high school gymnasium. Let's say wireless mics for awards presentation and the game announcer, mics for officials making the game calls and reinforcement for a live band playing the post game dance, Not enough PA, there will be nothing but mic feedback and echo from room reverberation. Speech will be unintelligable and the band will sound like crap. Now, put in a LARGER PA system, with gain capability to push the reverberant field to beyond the listeners (i.e. control the environment) and you will be able to understand the announcer and the band will sound good.

Same basic concepts apply to your listening room on a little different scale.

Psychoacoustically speaking, the larger the near field at the source, the larger the percieved size or stage will be. And in theatre applications that's real nice.

In my setup, I'm giving honest consideration to doing away with the center all together and using phantom mode where the center channel signal information is routed to the L&R mains. Uh oh, then I'll have inherent comb filtering and lobing issues. Oh well! Life it full of compromises.

Cheers! :14:

Let the shark attacks commence.

Dual-500
07-31-2010, 02:01 PM
Brad,
You may have convinced yourself it sounds good, but this really is a bad practice and I don't care how well it is done. Either you are hearing the effect of frequency combining, or you are hearing the tweeters cancelling, but there is no way this kind of setup is even close to flat. If you drop two rocks side by side in a pond, and watch the waves come together, that is what your set up is doing. When those waves meet, depending on the wavelength and frequency, they will either be is phase and boost the output at those frequencies, or they will be out of phase and cancel some frequencies. Either way this venture veers away from a flat frequency response, and depending on where you sit in the room, you will hear different tonalities and timbres coming from this setup.

Not recommended at all.
I'm genuinely interested, please tell me a little more about "Flat" frequency response please.

How is it achieved in any given environment? (let's limit discussion to HT envirnoments) Let's consider it in terms of "Dynamic System Performance" (not static anechoic chamber performance) which will include the environment. i.e. system excitation + environment = performance.

With consideration given to near field, far field, reverberent field and overall system levels.

How to eq the system? Do we even use electronic level correction basee upon room acoustic performance? If so, how to do it? A SPL meter? RTA? Where to place mic(s) and so on. What SPL to use during correction tuning.

Or simplify matters and install a pair of whatevers that perform "flat" in the lab, use no eq correction and call it a day?

What kind of system and under what conditions will reproduce audio without changes based upon listener location in the room?

Isn't this happening in the typical room all the time anyway? Isn't the enviroment more dynamic than static?

I maintain the OP is hearing the net result of an environment responding acoustically to excitation provided from a reproduction system. How do we make that "Flat" over the dymanics of theatre within the audible range of frequencies?

luvtolisten
07-31-2010, 03:24 PM
http://www.falstad.com/ripple/[/url]

When the applet comes up, click on one source and look at the wave pattern. Now click on two sources, and see that wave pattern. The first has a nice clean wave, and the second with two sources shows considerable interference in the wave patterns. This is what is happen with you two center setup.

http://www.falstad.com/ripple/

But if you click "ADD BORDERS" (or walls) for one source and 2 sources all bets are off. The theory make hold up if you had no walls, but in a real environment, there is little difference between one source or 2 source wave patterns.

Dual-500
07-31-2010, 03:47 PM
http://www.falstad.com/ripple/

But if you click "ADD BORDERS" (or walls) for one source and 2 sources all bets are off. The theory make hold up if you had no walls, but in a real environment, there is little difference between one source or 2 source wave patterns.
That's right.

And in the listening environment what reaches the ears = source + environment.

The environment being a variable based upon the excitation it's receiving at any given point in time. The environment will respond to frequency and intensity in different ways. The environment will respond to complex passages with numerous frequencies present differently than to a less complex waveform.

Ultimately, we can utilize treatments for the environment, location of system and electronic response corrections (equalization) to end up with the final product which is always the sum total of source + environment.

Flat Frequency responce when speaking in terms of the total system simply cannot be effectively achieved.

Even if we installed a system that had near field and gain performance to completely control the room - true flat response would only exist in the test or setup of the system at whatever set points were chosen for the tuning. Change any of that and all bets are off. Add to that the dynamic nature of the signals the system will reproduce.

Translation, flat frequency response in a listening environment COULD be achieved but only under static conditions - i.e. a given stimulus signal and given intensity. Change either and the system (environment + source) performance will also change and no longer be "Flat".

With proper test equipment and equalization, a room could be tuned flat. Flat with test tones or pink noise. Depending upon the available maximum system gain, it may perform flat going between the two. In practical application that would be essentially impossible to achieve however.

Music and Theatre are dynamic in nature and not static. Tuning a system (source + environment) for HT applications ultimately is a compromise between many factors. The end result being, when it sounds best to the tuner.

pixelthis
08-01-2010, 03:47 AM
That's right.

And in the listening environment what reaches the ears = source + environment.

The environment being a variable based upon the excitation it's receiving at any given point in time. The environment will respond to frequency and intensity in different ways. The environment will respond to complex passages with numerous frequencies present differently than to a less complex waveform.

Ultimately, we can utilize treatments for the environment, location of system and electronic response corrections (equalization) to end up with the final product which is always the sum total of source + environment.

Flat Frequency responce when speaking in terms of the total system simply cannot be effectively achieved.

Even if we installed a system that had near field and gain performance to completely control the room - true flat response would only exist in the test or setup of the system at whatever set points were chosen for the tuning. Change any of that and all bets are off. Add to that the dynamic nature of the signals the system will reproduce.

Translation, flat frequency response in a listening environment COULD be achieved but only under static conditions - i.e. a given stimulus signal and given intensity. Change either and the system (environment + source) performance will also change and no longer be "Flat".

With proper test equipment and equalization, a room could be tuned flat. Flat with test tones or pink noise. Depending upon the available maximum system gain, it may perform flat going between the two. In practical application that would be essentially impossible to achieve however.

Music and Theatre are dynamic in nature and not static. Tuning a system (source + environment) for HT applications ultimately is a compromise between many factors. The end result being, when it sounds best to the tuner.

Nope, when its accurate.
I HAVE HEARD some "good" systems, after fixing they were GREAT systems.
And we are talking about active centers, not passive mikes, different thang.
And no, you cant get a room flat, there will always be compromises in HT, sure, but
why shoot yourself in the foot from the get-go? YOU HAVE ENOUGH PROBLEMS
without creating new ones.
THE LEVELS of the different channels are not that critical in PROLXII , for example,
but a lot more so in DD. About 10 years or so ago I broke down and got a sound meter.
THE DIFFERENCE was amazing, really.
JUST because something is "decent" doesnt mean its enough.:1:

Dual-500
08-01-2010, 08:15 AM
Nope, when its accurate.
I HAVE HEARD some "good" systems, after fixing they were GREAT systems.
And we are talking about active centers, not passive mikes, different thang.
And no, you cant get a room flat, there will always be compromises in HT, sure, but
why shoot yourself in the foot from the get-go? YOU HAVE ENOUGH PROBLEMS
without creating new ones.
THE LEVELS of the different channels are not that critical in PROLXII , for example,
but a lot more so in DD. About 10 years or so ago I broke down and got a sound meter.
THE DIFFERENCE was amazing, really.
JUST because something is "decent" doesnt mean its enough.:1:
Accurate? Another term that gets misused.

I haven't heard a definition for "Flat Response" yet. You and I agree, a room can't be made to be flat. Good starting point.

Accurate? Yes, we strive for accurate. But, like "Flat Response" it ain't happening. Accurate is goal, not a destination. We get as close as possible to accurate.

Take a given room and test 10 different system/installations in it and what do you have? 10 different sets of results. They can all be tweaked towards "Accurate" and all 10 setups sound good. But all 10 will be inherently different.

Take one "Decent" system and setup/install in 10 different rooms and once again, even after tweaking, the net result is different in each room.

That's my simple point. The OP in this thread made a change that to him sounds good. It get's criticized and shot down as not being "Flat Response" or "Accurate" and that's not the case. Factors are not being taken into consideration. The listening environment plays a role in the end result. That role varies from room to room, some more than others. It's simply not a constant that can be conveniently ignored or disregarded when discussing net results.

The only point in the naysayer discussion was driver interaciton at the source and resultant comb effects. The room wasn't even in the equation, and the room is probably the big player here.

Shoot your self in the foot? Negative. There are times when nearfield radiation increases will net better sound regardless of resultant side effects derived from comb interaction. I didn't say EVERY time, I said sometimes. No ABSOLUTES here.

I doubt anyone on this thread would argue that if the components from the dual center channels loudspeakers were package into an integrated unit in such a way as to reduce comb effects from optimum driver placement that the result would not likely be inproved. However, that in and of itself doesn't negate the potential that what he did resulted in an improvement.

I submit the results the OP is getting using 2 -vs- 1 center channel speakers is an improvement just as he says it is. The increase in near field radiation could be improving upon overall environmental acoustic conditions (reverberant field control) that the side effect of comb interaciton is negated.

Thanks for the input - good discussion.

Sir Terrence the Terrible
08-01-2010, 09:31 AM
http://www.falstad.com/ripple/

But if you click "ADD BORDERS" (or walls) for one source and 2 sources all bets are off. The theory make hold up if you had no walls, but in a real environment, there is little difference between one source or 2 source wave patterns.

You need to look again, and pay attention to the first few seconds of the reflection pattern. The 2 sources with borders filled the room with reflections far quicker than the single source, and they had a much more complex interaction far more quickly than the single source. The first wave of the single sources had smooth perfect half arch until it hit a border, the 2 source had waves colliding very quickly, which created a complex interaction within the first few seconds of the launch of the wave.

Sir Terrence the Terrible
08-01-2010, 10:38 AM
Accurate? Another term that gets misused.

It gets misused because it takes work to achieve it, and few have really tried.


I haven't heard a definition for "Flat Response" yet. You and I agree, a room can't be made to be flat. Good starting point.

The room can't be flat, but at least the system that goes into it can. With good EQ, proper placement, and room treatments, you can get awful close - close enough for the cigar.


Accurate? Yes, we strive for accurate. But, like "Flat Response" it ain't happening. Accurate is goal, not a destination. We get as close as possible to accurate.

Whether it happens or not depends highly on the skill of the individual(a person well educated in small room acoustics) and interpretation of the measurements obtained from the room. From 200hz downward it all depends on placement, treatments, and EQ. From 200hz up, it is on the shoulders of the equipment itself. Nothing can achieve a ruler flat response, but a well calibrated system/room interaction will certainly remove far more peaks and valleys than a untreated room, or uncalibrated system.


Take a given room and test 10 different system/installations in it and what do you have? 10 different sets of results. They can all be tweaked towards "Accurate" and all 10 setups sound good. But all 10 will be inherently different.

Here you are correct, but this is stating the obvious.


Take one "Decent" system and setup/install in 10 different rooms and once again, even after tweaking, the net result is different in each room.

This all highly depends on the shape of the different rooms, and how the system is placed in it.

This I don't agree with, only because I have actually done it. I had one system of which I set up in one room (14x17x8), tore down and set up in another room (12x15x10). Before tweaking, their response in both rooms(especially above 200hz or so) was pretty darn close, but below 200hz is where I saw the most deviation, and because of where I placed the sub (in the middle of the room against the front wall) and mains (at least three feet from any wall toed in), even below 200hz the response curves for each room were not that far off. Once I tweaked the system for both rooms, the both had almost identical frequency curves.


That's my simple point. The OP in this thread made a change that to him sounds good. It get's criticized and shot down as not being "Flat Response" or "Accurate" and that's not the case.

It got shot down because it is a poor practice not grounded anywhere in home theater, or the theater for that matter. There is a reason why movie theaters only have one center channel, and there is a reason why THX, Dolby, and Dts only recommends a single center channel in home theater environments. There are acoustical principles that support a single channel, and not two center speakers spaced apart.



Factors are not being taken into consideration. The listening environment plays a role in the end result. That role varies from room to room, some more than others. It's simply not a constant that can be conveniently ignored or disregarded when discussing net results.

If you start off on the wrong foot acoustically speaking from the speakers, then the room is not going to change that one bit. The applet demo clearly shows that. Even with no borders, there is considerable acoustical wave interference with two sources playing the same signals. Throw the walls up, and the interference just gets easier to hear.


The only point in the naysayer discussion was driver interaciton at the source and resultant comb effects. The room wasn't even in the equation, and the room is probably the big player here.

If you start off with lobing from the speakers, the room is not going to change that as that is a function of driver interaction. If you start off with comb filtering coming from the speakers, the room will just make it worse. A room does not make a bad set up choice better, it can often make it far worse.


Shoot your self in the foot? Negative. There are times when nearfield radiation increases will net better sound regardless of resultant side effects derived from comb interaction. I didn't say EVERY time, I said sometimes. No ABSOLUTES here.

Rather than creating "grey areas" look at the gentleman's set up. He has two speakers closely packed together recessed in a cavity like environment. He has two tweeters closely packed together which efficiently interact with each other (Proximity Effect) to boost and cancel signals based on their wavelengths. He has two spaced woofers (which we know causes lobing for off axis listeners) set up in a cavity which creates a boundary reinforcement effects and comb filtering. This is all happening even before the first fractured wave (what you get from this kind of set up) hits the wall once. Being in the near field will just make this more audible in the form of more diffusion to the image.



I doubt anyone on this thread would argue that if the components from the dual center channels loudspeakers were package into an integrated unit in such a way as to reduce comb effects from optimum driver placement that the result would not likely be inproved. However, that in and of itself doesn't negate the potential that what he did resulted in an improvement.

I disagree. Have you ever heard of a tapered array, or vertical placement? If you took this same set up, and flipped it vertically, it would change the result dramatically. You would have shifted the lobing of the woofers to the vertical plane, which would(especially if you moved it out of the cavity) result in less interaction with the floor and ceiling, and create a wider horizontal dispersion pattern. If you taper one woofers response going up in frequency, it will not have the destructive driver interference at higher frequencies that an untapered response will have. A piece of foam inserted between the two stacked tweeters will reduce any interaction between them at lower frequencies in the operation range, and eliminated altogether at higher frequencies.

Anyone can say there is an improvement if not just to justify the cost of what they have done. If you do not have a reference to what is really good, then you could justify anything.
I can convince myself a speaker with a poor frequency response sounds good. Bose owners do it everyday.


I submit the results the OP is getting using 2 -vs- 1 center channel speakers is an improvement just as he says it is. The increase in near field radiation could be improving upon overall environmental acoustic conditions (reverberant field control) that the side effect of comb interaciton is negated.

Thanks for the input - good discussion.

He has done nothing to control the reverberant field, that can only be done with room treatments. What he has done in the nearfield is created all kinds of issues that negatively impact the nearfield response as well. You really cannot negate comb filtering unless you remove the source that creates it.

There is a reason that THX, Dolby, and Dts only include one center speaker in their home theater layouts, and why the ITU, AES and SMPTE committees only sanctions the use of a single center speaker. It is for all of the reasons I have mentioned here. You gain nothing with this practice except a more narrow dispersion pattern, lobing, non complimentary driver interaction, poor frequency response, and various other problems. Your attempt to justify this if one understands driver interaction and small room acoustics fails miserably.

IMAX uses two center speakers in their old IMAX configuration. The two center speakers never played together, only one is used at a time for just the reasons I have mentioned. Your driving the ambulance for the OP did not save the patient at all.

Dual-500
08-01-2010, 12:26 PM
.......1) Once I tweaked the system for both rooms, the both had almost identical frequency curves.

2) It got shot down because it is a poor practice not grounded anywhere in home theater, or the theater for that matter. There is a reason why movie theaters only have one center channel, and there is a reason why THX, Dolby, and Dts only recommends a single center channel in home theater environments. There are acoustical principles that support a single channel, and not two center speakers spaced apart.

3) He has done nothing to control the reverberant field, that can only be done with room treatments. What he has done in the nearfield is created all kinds of issues that negatively impact the nearfield response as well. You really cannot negate comb filtering unless you remove the source that creates it.
You are obviously intelligent, well spoken and very knowledgeable in audio. Good discussion - thanks for participating and taking the time to do so.

1) Yes, with tweaking one can obtain similar results using test equipment. That's part of my argument here - you didn't state they sounded the same, felt the same, invoked the same experience. You went straight to test gear. I can tune two guitars with test gear and they will sound different being played.

2) Moot point. His system design could be improved upon, I already acknowledged that. Doesn't have any relevance to whether it sounds better or not with dual center channel loudspeakers.

3) Here I disagree. By virtue of adding the second center channel loudspeaker, he has absolutely improved the systems ability to control the reverberant field in the room. A good example is the HS gymnasium. Put one of our HT systems in basketball gymnasium and listen to it. Won't sound so good. Now put a 10kw pro system in it's place and the results are dramatically different even at similar sound pressure levels. Why? Nearfield radiation energy.

Air has mass. As such, standing waves have mass. There is a point when the energy from the source will overcome the standing waves making them essentially null and void. The reason we "Tweak" or "Tune" a room is to compensate for the systems lack of control of the reverberant field.

There are three basic sound field components in a typical listening environment - near field (source), far field (near field + reverberant field) and the reverberant field itself.

Ever been in a stadium or arena where you couldn't understand the announcer or music wasn't clear? Too much echo or slap back. Articulation and consonants lost. We all have. Ever been to a rock show, get there a little late with reserved seats. Walking across the parking lot you can hear the band playing like the building isn't even there? That's when they have a large enough PA system in the house to overcome the reverberant field all together and the near field of the system is expanded beyond the physical boundaries of the building. Little or no eq correction in the house system was needed or applied in such a case.

Both scenarios happen all the time. Most of our HT systems are somewhere in the middle of the two examples above - able to sound good, speech articlation is good, yet not enough power to completely overcome the room reverberant field - hence the use of tuning and treatments.

Take a room, excite the room with a near field of 2" square @ 100 db measured at the source. Let's assume optimum placement of the source in the environment for this example. Now let's expand the near field at the source to 12" square, same measured intensity of 100 db. What happens to it's ability to control room reverberations? Take it up another level - 10' square near field size, same measured intensity of 100 db.

In example 1 the acoustic power generated is 1/60 of that in the 3rd example. Same measured intensity at the source, same inverse square law applies. The 3rd example will contol standing waves much better even at the same SPL. Because of the effective acoustic power radiation. The near field power radiation can be increased (maximum system gain) to the point the reverberant field and far fields dissappear or are nulled out by the near field power radiation.

I attended a USITT seminar in Oakland, CA back in the mid 80's and my perspective for audio systems was changed forever when listening to a lecture on sound design given by a professor from the Yale School of Drama. He began by stating (paraphrased) "When approaching a design, the first thing to do is determine what emotional responses we seek to elicit from the audience, then go about the task of determining how we are going to achieve it".

Never in the discusson did his perspective migrate into specifications, response curves, db meters, sound pressure levels, hardware - these are simply the tools and properties of the trade - the means to an end.

The OP stated his system sounds better - it does. Yet, the chorus seems hell bent on leather to disprove that possibility. He already stated it's a fact.

Not suggesting he couldn't do better with it. But, neither can I definitively state it sounds worse.

The simplicity of design execution of a typical HT setup is something a hobbyist can enjoy. Let him enjoy.

Mr Peabody
08-01-2010, 01:34 PM
SteveW, I didn't follow your example. What was the variable in each example? I realize the size but did you change seating or room size, what changed the field? You always remained a 100dB in each example so I don't see how there would be any difference. 100dB in a closet, a room or auditorium is still 100dB. And in an auditorium it would be unlikely to have 100dB at every step from source to wall. If you had 100dB at the source it would drop as the distance increases.

Dual-500
08-01-2010, 02:15 PM
SteveW, I didn't follow your example. What was the variable in each example? I realize the size but did you change seating or room size, what changed the field? You always remained a 100dB in each example so I don't see how there would be any difference. 100dB in a closet, a room or auditorium is still 100dB. And in an auditorium it would be unlikely to have 100dB at every step from source to wall. If you had 100dB at the source it would drop as the distance increases.
Thanks for asking.

The concept I'm discussing is acoustic power radiation. That's the variable - acoustic power generated - near field size x intensity x air mass = acoustic energy. Simple db measurements ar only a single point in space. That's the real output of an audio system. It goes beyond what we measure at a single point in space at 1m.

Any given system as max gain which is in essence maximum acoustic power generation capability. This is of course goverened by the usual paramaters we deal with everyday on audio forums. Amp power, impedance, power handling capactiy, bandwidth, directivity and sensitivity. There is one more factor - the size of the near field or acoustic power generated. We are moving air. How much air? Air has mass, more air = more mass = more acoustic power.

We can take a 100w system in a 1000 seat gym and feed music to it and it won't sound too good. Setup the system at 1m with a test tone for max power out. Then inject the music.

Now take a 10kw pro setup, with the same horizontal and vertical "Q" and set to same level @ 1m and then inject the same music at the same level.

I will guarantee you the results will be vastly different. Why? Because the acoustic power generated is greater with the larger system.

That's what the OP did when he added the second center. The acoustic power capability of the system was essentially doubled, the near field size doubled. (let's not haggle about comb effects as they work both ways)

An audio system provides excitation to the environment. Your only considering db measurements and not considering acoustic power.

Again, we can measure your or my HT setup and set it to 100db out at 1m in a 10,000 seat arena. Then take a 50kw concert array and set it to 100db @ 1m in the same arena and at 10', 50' or 100' back, the larger system will sound better and the measured sound pressure will be greater at distance. Because the standing waves will be better controlled by the larger system by virtue of the additional acoustic power that is generated.

Acoustic power generated is what allows for the system to control the environment. The more power, the better the contol.

Mr Peabody
08-01-2010, 03:04 PM
So what you are saying is because two center would have four woofer cones moving more air, than two cones would, the field has more energy? If I am understanding this correctly it makes sense and why I find large woofers more accurate in reproducing drums, in a general sense, over smaller woofers. Some speakers with small woofers can play amazingly low but still seems to fall a bit short on the body of a drum tone. Hope I didn't misunderstand and get off on a tangent :)

Dual-500
08-01-2010, 04:34 PM
So what you are saying is because two center would have four woofer cones moving more air, than two cones would, the field has more energy? If I am understanding this correctly it makes sense and why I find large woofers more accurate in reproducing drums, in a general sense, over smaller woofers. Some speakers with small woofers can play amazingly low but still seems to fall a bit short on the body of a drum tone. Hope I didn't misunderstand and get off on a tangent :)
Yes exactly. In racing, there ain't no substitute for cubic inches. I audio, size matters.

In a reproduction environment we are simply taking an electrical stimulus and converting that into a mechanical stimulus. What we hear is the net result of such.

I'm not suggesting here there would be a hugh difference in his setup or results. Nor, that proper orientation of the drivers would not net an improvement.

Just saying it may sound better - the OP claims it does. So, I'm not inclined to attempt to debunk it using typical hobbyist paradigms.

I'm a hobbyist too nowadays - not bashing.

Hobbyist: Buy speaker x, amplifier y, processing setup of z and install in listening room. A skilled/experienced hobbyist will take said setup and work placement, room treatment and system tuning to arrive at a spot of optimum performance. Typically though, they only tune to one spot in the room.

Professional Sound Designer: Will assess requirements, evaluate environment, then start shaping a course of action. If they are a contractor cost, schedule and other considerations will also be taken into consideration. If working in an institution, there could be other constraints, hardware inventory, rental budget, etc. If it's a fixed install in club or church comes archtectual specs, elevations and renderings. For a touring system another set of variables. For a regional sound contractor it's a lot of pure experience in play. Make optimum use of inventory, while meeting or exceeding customer expectations. Take less gear out an you can send another crew out to handle a smaller job. Get paid twice that day.

There must be an awareness of how much PA is needed - can't use too much, drives prices out of competetive realm, not enough and sound is bad - damage to reputation.

To reinforce for instance a high school graduation ceremony in a big budget high school with large student body that's held in the football stadium with 5-10,000 seats presents unique challanges. Grandstands with infield seating in front and stage beyond that. Front fills, side fills, rear fills, time delay, etc. And it's outdoors. Gotta cover all the seats, not too loud for grandma, but speech intelligibility must be good on the upper deck and in the bleachers going up 50 rows. If it's not, you won't be coming back next year. Truck payment is tough to make when you're not working.

And instutution is about as much fun. Musical theatre in a house for public presentation - been there done that. Wireles mic's on actors, set mic'd up, apron in front of stage mic'd up. Live band behind stage mic'd up. Director demands the house including balcony and under balcony seats sound good - not too loud. And of yeah, the system must be behind scrim flats and unobtrusive - i.e. when the actors are speaking the point source localization is towards them and not a pair of stacks or flying array.

There's a degree of group think and paradigms on this thread that frankly bothers me. Somewhat narrow view of all things audio if you will.

Sometimes, it's good to blow dowm a few walls!

Cheers dude!!! :3:

PeruvianSkies
08-01-2010, 06:13 PM
So what if a person decided to connect all the speakers into their receiver in the wrong places and therefore had the surrounds mixed with the fronts and left and right were backwards and various other exchanges, but they claimed that they loved the way it sounded this way and think it is highly recommended?

By this we are saying that everyone has their own version of right and wrong setup and therefore there really isn't any correct or incorrect way of doing HT, which means to each their own and unless we can hear each others systems there is no way of really knowing?

Come on....

I think we are missing some of the fundamentals that go into this hobby and there are proper ways to do various things that each of us have tried in our own ways and logic tells us that we don't have to fall off a skyscraper to know it's a bad idea.

Sir Terrence the Terrible
08-01-2010, 08:19 PM
You are obviously intelligent, well spoken and very knowledgeable in audio. Good discussion - thanks for participating and taking the time to do so.

1) Yes, with tweaking one can obtain similar results using test equipment. That's part of my argument here - you didn't state they sounded the same, felt the same, invoked the same experience. You went straight to test gear. I can tune two guitars with test gear and they will sound different being played.

Yes, I go straight to test gear, because it is futile to create an "emotional" system that is suitable for everyone. Everyone's emotions are different, and stimulated differently. What stirs me emotionally may not stir you, so I don't chase after subjective variables, but stick to objective ones tweaked to taste.


2) Moot point. His system design could be improved upon, I already acknowledged that. Doesn't have any relevance to whether it sounds better or not with dual center channel loudspeakers.

Oh, its quite relevant. There is a great body of evidence that does not support the dual center set up, which is why none of these organizations have come out in favor of it.


3) Here I disagree. By virtue of adding the second center channel loudspeaker, he has absolutely improved the systems ability to control the reverberant field in the room. A good example is the HS gymnasium. Put one of our HT systems in basketball gymnasium and listen to it. Won't sound so good. Now put a 10kw pro system in it's place and the results are dramatically different even at similar sound pressure levels. Why? Nearfield radiation energy.

Sorry but you have this all wrong. First, most room in houses are not big enough to even speak about the reverberant field, that is the territory of auditoriums and concert halls where the pathways of reflections(and therefore their Reverberant times)are longer. If we sit close to the speakers as we sit in HT rooms, then the reverberant field is immaterial in the equation, the pathways and reverberant times are a lot shorter. Second you are totally missing dispersion as a component of performance. If he was stacking those two speakers in the vertical plane, the woofers interactions are complimentary on the horizontal plane, and destructive in the vertical plane which equals better radiation energy. This would result in a better frequency response over a very wide horizontal plane, and less interaction with the ceiling and floor. Stacking those same two speakers in the horizontal plane creates destructive interactions in the horizontal plane(lobing) which means an uneven frequency response off axis, a poor off axis speaker performance, which negatively affects both the nearfield, and the reverberant field alike. The floor and the ceiling are fully engaged thereby creating a short reflective path towards the floor, and longer one to the ceiling, and comb filtering between the two. Not good.


Air has mass. As such, standing waves have mass. There is a point when the energy from the source will overcome the standing waves making them essentially null and void. The reason we "Tweak" or "Tune" a room is to compensate for the systems lack of control of the reverberant field.

What you are speaking of does not happen in small rooms, this is a function of a much larger room - a room approaching the size of a theater or large auditorium. Standing waves in smaller room rooms are very audible, and cannot be swamped out unless the listening seat is very close to the speakers themselves. Much of what you are talking about occurs in the very deep bass, far below what is attainable with these dual center speakers.

The reason why we tweak or tune a system has more to do with the interaction of bass waves with the surrounding surfaces. If you try to swamp a standing wave by increasing the volume, you just excite the resonant frequency more. The only way to reduce standing waves is to move the sub out of the high pressure zones within the room(along with the listening seat). That is the only way period.

In larger rooms standing waves are far less audible, as they are much lower in frequency than in small rooms, and often the sources cannot drive them hard enough(stimulate) to make them audible.


There are three basic sound field components in a typical listening environment - near field (source), far field (near field + reverberant field) and the reverberant field itself.

In the typical listening room in homes those components have ratios. The near field accounts for 80-90 percent of what we hear, and we don't sit far enough away from the sources to truly give equality to the reverberant field, the rooms are just too small. These really are larger room principles you are trying to apply to small rooms. I would apply these principles when tuning a movie theater, or dubbing stage, not a HT room. I have done all three.


Ever been in a stadium or arena where you couldn't understand the announcer or music wasn't clear? Too much echo or slap back. Articulation and consonants lost. We all have. Ever been to a rock show, get there a little late with reserved seats. Walking across the parking lot you can hear the band playing like the building isn't even there? That's when they have a large enough PA system in the house to overcome the reverberant field all together and the near field of the system is expanded beyond the physical boundaries of the building. Little or no eq correction in the house system was needed or applied in such a case.

This has nothing to do with small rooms, and you must know this right? This comparison can't even effectively translated into the typical listening room in houses, the rooms are far too small to create this effect. What dogs articulation in small rooms are early arriving reflections combining with later reflections that create diffusion and comb filtering, not long reflections which create echo's and long reverberation times. In small rooms low frequencies fill the room instantly, and mid and highs have longer build up times, more density, which makes any resonances in those frequencies inaudible. Slap echo's are audible as a twang, but not as a total echo like in large spaces.


Both scenarios happen all the time. Most of our HT systems are somewhere in the middle of the two examples above - able to sound good, speech articlation is good, yet not enough power to completely overcome the room reverberant field - hence the use of tuning and treatments.

This makes no sense to me whatsoever. I have never heard a HT room that had enough internal volume to create the scenario you have stated. I have heard auditoriums, gymnasiums and stadiums that did.


Take a room, excite the room with a near field of 2" square @ 100 db measured at the source. Let's assume optimum placement of the source in the environment for this example. Now let's expand the near field at the source to 12" square, same measured intensity of 100 db. What happens to it's ability to control room reverberations? Take it up another level - 10' square near field size, same measured intensity of 100 db.

In example 1 the acoustic power generated is 1/60 of that in the 3rd example. Same measured intensity at the source, same inverse square law applies. The 3rd example will contol standing waves much better even at the same SPL. Because of the effective acoustic power radiation. The near field power radiation can be increased (maximum system gain) to the point the reverberant field and far fields dissappear or are nulled out by the near field power radiation.

None of this is applicable to the issue at hand. All even mentioning this does is muddy the waters of the discussion. What you are saying can be done by just moving closer to the source. There is no need to increase anything, unless the source is not suitable size wise for the size of the room.


I attended a USITT seminar in Oakland, CA back in the mid 80's and my perspective for audio systems was changed forever when listening to a lecture on sound design given by a professor from the Yale School of Drama. He began by stating (paraphrased) "When approaching a design, the first thing to do is determine what emotional responses we seek to elicit from the audience, then go about the task of determining how we are going to achieve it".

This does not sound like a function of the system itself, but the mix the system will reproduce. I learned this same principle at film school when approaching the design of a soundtrack mix. All I want my reproduction chain to do is convey the mix to the audience, not try and get an emotional response from the speakers themselves. The concept when applied to the reproduction chain places it in front of the mix itself , not exactly what we are looking for.


Never in the discusson did his perspective migrate into specifications, response curves, db meters, sound pressure levels, hardware - these are simply the tools and properties of the trade - the means to an end.

Perhaps you are right, but these tools are necessary to get a good result in the end, and the OP has not applied any of them, and his system does not reflect their use as well. In looking at the way the OP system is set up, there is no way he is getting any improvement from anything. The first rule of good sound is to use these tools as the means to and end, or you don't really have an end in their absence.


The OP stated his system sounds better - it does. Yet, the chorus seems hell bent on leather to disprove that possibility. He already stated it's a fact.

How do you know it sounds better, have you heard it? The chorus is right in this case, as the very nature of what the OP is doing defies good acoustical and set up principles in spades. If it in fact sounded better, you can bet THX, Dolby, Dts, SMPTE, AES, and ITU organizations would extol the use of dual centers. Since in fact testing has produced negative results for this kind of set up, none of them recommend it.

Facts must be verified, or they are just anecdotal without support.


Not suggesting he couldn't do better with it. But, neither can I definitively state it sounds worse.

The simplicity of design execution of a typical HT setup is something a hobbyist can enjoy. Let him enjoy.

I am puzzled by your defense of this kind of thing. You act as if this kind of set up has never been tested, and quite frankly it has. When attending USC's film school, I had Tomlinson Holmann (creator of the THX certification criteria) and Dr. Floyd Toole as my professors. My minor is in acoustical science along with a major in film and television post production with an emphasis on sound. None of what you are stating lines up one bit with what they have taught me when it comes to speaker/room interaction in small rooms. It does apply when we are talking about large rooms. It might help if your comments and observations lined up better with the circumstances at hand.

Sir Terrence the Terrible
08-01-2010, 08:33 PM
Hobbyist: Buy speaker x, amplifier y, processing setup of z and install in listening room. A skilled/experienced hobbyist will take said setup and work placement, room treatment and system tuning to arrive at a spot of optimum performance. Typically though, they only tune to one spot in the room.

There is two approaches when tuning a system. You tune to one spot(which is mostly recommended as there is only one place of perfect fusion in small rooms), and there is another school of thought that tunes for as many listening positions that are in the room, which mostly leads to average sound everywhere. I tune for a perfect one spot(or as close to perfect as possible), and secondarily for other listening positiond for as best sound as they can get. This yields one almost perfect spot, and many decent spots.


Professional Sound Designer: Will assess requirements, evaluate environment, then start shaping a course of action. If they are a contractor cost, schedule and other considerations will also be taken into consideration. If working in an institution, there could be other constraints, hardware inventory, rental budget, etc. If it's a fixed install in club or church comes archtectual specs, elevations and renderings. For a touring system another set of variables. For a regional sound contractor it's a lot of pure experience in play. Make optimum use of inventory, while meeting or exceeding customer expectations. Take less gear out an you can send another crew out to handle a smaller job. Get paid twice that day.

A sound designer does not design sound systems, they design effect tracks and create live or recorded mixes. A sound system designer designs sound systems with the room and purpose in mind. I am both a sound designer, and a system designer, and I know the difference between the two.

There are one very important factor you are missing here. When we talk about the combination of near-field, far-field, and reverberant field, the sound source has to be coming from one direction, much like a PA system in the front of the auditorium or concert hall(whether it is flown, or a stage stack). In a home theater, there is no reverberant field, as you are surrounded by speakers in a 7.1 setup, and at least enveloped with a 5.1 system. You are too close to all of the speakers for a reverberant environment to really form. You only get a reverberant field when the reflections are more dominate in amplitude, have very long reflective paths that diffuses the output from the source elements, and which reduce the high frequency content of the signals. This complex interaction does not happen with multichannel set ups in small rooms.


There must be an awareness of how much PA is needed - can't use too much, drives prices out of competetive realm, not enough and sound is bad - damage to reputation.

To reinforce for instance a high school graduation ceremony in a big budget high school with large student body that's held in the football stadium with 5-10,000 seats presents unique challanges. Grandstands with infield seating in front and stage beyond that. Front fills, side fills, rear fills, time delay, etc. And it's outdoors. Gotta cover all the seats, not too loud for grandma, but speech intelligibility must be good on the upper deck and in the bleachers going up 50 rows. If it's not, you won't be coming back next year. Truck payment is tough to make when you're not working.

Once again you are back to large spaces, which have no relevance to HT rooms.


And instutution is about as much fun. Musical theatre in a house for public presentation - been there done that. Wireles mic's on actors, set mic'd up, apron in front of stage mic'd up. Live band behind stage mic'd up. Director demands the house including balcony and under balcony seats sound good - not too loud. And of yeah, the system must be behind scrim flats and unobtrusive - i.e. when the actors are speaking the point source localization is towards them and not a pair of stacks or flying array.

For eight years I was an audio engineer on Broadway, and most of the systems in those locations are already set in place for the best sound coverage in the theater. Localization in a theater environment is not what you want, consistent even sound coverage is, which is why most theater installations are a permanent part of the theater.


There's a degree of group think and paradigms on this thread that frankly bothers me. Somewhat narrow view of all things audio if you will.

This group think exists because their are principles that have been tried, tested and proven to give good results. Follow the rules, and you get an expected good result. Create your own rules, and you have something only you can enjoy.


Sometimes, it's good to blow dowm a few walls!

Cheers dude!!! :3:

If blowing down walls is what you set out to accomplish, then you failed the mission. No offense, but your what you are stating here does not apply to the OP's situation. Not one bit I am afraid.

Dual-500
08-01-2010, 08:42 PM
Good stuff Terrence. I'll read and digest tomorrow night and comment.

Thanks for the discussion.

I do have some quesitons on tuning technique for HT applications - which by definition are unique to HT.

Cheers! :thumbsup:

Sir Terrence the Terrible
08-01-2010, 08:45 PM
So what you are saying is because two center would have four woofer cones moving more air, than two cones would, the field has more energy? If I am understanding this correctly it makes sense and why I find large woofers more accurate in reproducing drums, in a general sense, over smaller woofers. Some speakers with small woofers can play amazingly low but still seems to fall a bit short on the body of a drum tone. Hope I didn't misunderstand and get off on a tangent :)

Keep in mind that one larger woofer does not have the same negative side effects as using four spaced ones. If you are going to use four woofers, there has to be some way for them to couple together to effectively move more air as one driver(proximity boost). Spaced apart coupling is not effective, clustered together tightly it is. If you have ever seen a subwoofer in an IMAX installation, it has four 15" in what is called a "diamond cluster", a tight diamond shape pattern which causes the four 15" drivers to move the air as one large
driver.

If you really want to move more air, you get a larger center channel with larger drivers, not two separate speakers in the name of moving more air. Let's be logical here, just how much more air is going to be moved with those small drivers in such a small cabinet like the OP has.


If

PeruvianSkies
08-01-2010, 09:21 PM
Keep in mind that one larger woofer does not have the same negative side effects as using four spaced ones. If you are going to use four woofers, there has to be some way for them to couple together to effectively move more air as one driver(proximity boost). Spaced apart coupling is not effective, clustered together tightly it is. If you have ever seen a subwoofer in an IMAX installation, it has four 15" in what is called a "diamond cluster", a tight diamond shape pattern which causes the four 15" drivers to move the air as one large
driver.

If you really want to move more air, you get a larger center channel with larger drivers, not two separate speakers in the name of moving more air. Let's be logical here, just how much more air is going to be moved with those small drivers in such a small cabinet like the OP has.


If

EXACTLY! I am glad that someone else is not smoking crack around here regarding this. Despite my differences with Sir T in other areas here, I have to say that this is one time I am in complete agreement.

pixelthis
08-02-2010, 11:44 AM
Accurate? Another term that gets misused.

I haven't heard a definition for "Flat Response" yet. You and I agree, a room can't be made to be flat. Good starting point.

Accurate? Yes, we strive for accurate. But, like "Flat Response" it ain't happening. Accurate is goal, not a destination. We get as close as possible to accurate.

Take a given room and test 10 different system/installations in it and what do you have? 10 different sets of results. They can all be tweaked towards "Accurate" and all 10 setups sound good. But all 10 will be inherently different.

Take one "Decent" system and setup/install in 10 different rooms and once again, even after tweaking, the net result is different in each room.

That's my simple point. The OP in this thread made a change that to him sounds good. It get's criticized and shot down as not being "Flat Response" or "Accurate" and that's not the case. Factors are not being taken into consideration. The listening environment plays a role in the end result. That role varies from room to room, some more than others. It's simply not a constant that can be conveniently ignored or disregarded when discussing net results.

The only point in the naysayer discussion was driver interaciton at the source and resultant comb effects. The room wasn't even in the equation, and the room is probably the big player here.

Shoot your self in the foot? Negative. There are times when nearfield radiation increases will net better sound regardless of resultant side effects derived from comb interaction. I didn't say EVERY time, I said sometimes. No ABSOLUTES here.

I doubt anyone on this thread would argue that if the components from the dual center channels loudspeakers were package into an integrated unit in such a way as to reduce comb effects from optimum driver placement that the result would not likely be inproved. However, that in and of itself doesn't negate the potential that what he did resulted in an improvement.

I submit the results the OP is getting using 2 -vs- 1 center channel speakers is an improvement just as he says it is. The increase in near field radiation could be improving upon overall environmental acoustic conditions (reverberant field control) that the side effect of comb interaciton is negated.

Thanks for the input - good discussion.

Of course you cant get totally straight up and down flat outside a lab and very few high end setups, but you can get amazingly close, but not if you start off shooting yourself in the foot.
This sort of frequency cancellation is so effective that its used in several brands of headphones.
This sort of massively inaccurate setup is universally decried by all who know better.:1:

pixelthis
08-02-2010, 11:51 AM
[QUOTE=PeruvianSkies]So what if a person decided to connect all the speakers into their receiver in the wrong places and therefore had the surrounds mixed with the fronts and left and right were backwards and various other exchanges, but they claimed that they loved the way it sounded this way and think it is highly recommended?


PERSONAL EXPERIENCE?



By this we are saying that everyone has their own version of right and wrong setup and therefore there really isn't any correct or incorrect way of doing HT, which means to each their own and unless we can hear each others systems there is no way of really knowing?


what is this the situational ethics version of setting up a system?
PEOPLE PREACHING such a system claim that their is no set system of morality,
whatever you do is okay. They always fail to mention murdering people.
THERE IS AN OBJECTIVE WAY to hook any system up that is going to be best,
its called science, and you can argue that "if it feels good do it", but there is still
a certain set of objective rules to follow concerning setting up a HT.
And using two centers is not one of them




Come on....


I think we are missing some of the fundamentals that go into this hobby and there are proper ways to do various things that each of us have tried in our own ways and logic tells us that we don't have to fall off a skyscraper to know it's a bad idea.
Like using two centers.:1:

brad1138
08-02-2010, 06:53 PM
I want to point out, I have been professionally in and around the audio industry for ~20 years and a hobbyist since I got my first home stereo for my 10th B-day, 33+ years ago. I worked for 8+ years at a well respected, local, high end AV dealer (http://www.descoav.com/index.php) that has been around for over 40 years. I am not coming at this without knowledge of HT/Stereo design theory.

I get that the 2 center approach has draw backs, I can hear them. Slightly less pinpoint/focused image from the center for 1. However in my setup and situation, it has benefits, and in the end I like the Dual center sound better than the single. I am not some AV/HT noob, I have a fairly critical ear. Of course I could convince myself the sky is orange if I really wanted to, but I have no reason to convince myself the dual centers sound better, it was/is an experiment. If I hadn't liked the sound more I would have switched back and probably posted that experience as well. Last night while watching The Hangover with my son I let him have the center seat I almost always sit in, I was about 4-5 feet off center, and the "benefits" were present there as well.

Another point no one seems to have thought about. Some have said, "just go buy", I can't afford to just go out and buy the exact correct piece(s) for my system. If I could I would probably have a, single, top of the line center behind an acoustically transparent 120" projection screen. So I look for the best sound with what I have and can afford to buy. As I posted originally, the S1s weren't being used, and I came up with a way to, IMO, improve my system for free. I am very proud of, and happy with, the system (http://forums.audioholics.com/forums/showpost.php?p=701345&postcount=342) I have been able to put together over the last 20 years or so, for very little $.

Feel free to continue your (seemingly never ending) argument against it. I get your text books say it isn't a good idea (I have never been one to go by the books), and your expierience is that it doesn't sound as good. This is my experience & system and I don't need your approval.

I am always tinkering with my system. I will keep it like this for a while, I may change back at some point, especially if I get the M-Csi matching center for my M-3si's I have been looking for the right deal on, but I am very happy with the sound currently.

Thanks again,
Brad

Sir Terrence the Terrible
08-02-2010, 07:21 PM
I want to point out, I have been professionally in and around the audio industry for ~20 years and a hobbyist since I got my first home stereo for my 10th B-day, 33+ years ago. I worked for 8+ years at a well respected, local, high end AV dealer (http://www.descoav.com/index.php) that has been around for over 40 years. I am not coming at this without knowledge of HT/Stereo design theory.

If this were the case, then you should have known that what you are trying is not a good idea at all. A hobbyist or a salesman probably knows about as much about room acoustics and wave interaction as I know about rocket science. None of these amateurish credentials validates any special knowledge when it comes to the proper way of setting up a home theater.


I get that the 2 center approach has draw backs, I can hear them. Slightly less pinpoint/focused image from the center for 1. However in my setup and situation, it has benefits, and in the end I like the Dual center sound better than the single. I am not some AV/HT noob, I have a fairly critical ear. Of course I could convince myself the sky is orange if I really wanted to, but I have no reason to convince myself the dual centers sound better, it was/is an experiment. If I hadn't liked the sound more I would have switched back and probably posted that experience as well. Last night while watching The Hangover with my son I let him have the center seat I almost always sit in, I was about 4-5 feet off center, and the "benefits" were present there as well.

Brad, I do think you are really trying to justify something that acoustically speaking cannot be justified. Some of us know better, and have heard this whole schmeel before.

Anyone can say they have a critical ear, anyone can make any claim for that matter. But I have heard enough of these kinds of setups to know that you are not fooling me, but you really are fooling yourself.


Another point no one seems to have thought about. Some have said, "just go buy", I can't afford to just go out and buy the exact correct piece(s) for my system. If I could I would probably have a, single, top of the line center behind an acoustically transparent 120" projection screen. So I look for the best sound with what I have and can afford to buy. As I posted originally, the S1s weren't being used, and I came up with a way to, IMO, improve my system for free. I am very proud of, and happy with, the system (http://forums.audioholics.com/forums/showpost.php?p=701345&postcount=342) I have been able to put together over the last 20 years or so, for very little $.

If this is all you have, then you would do far better by stacking the two speakers in the vertical plane(instead of the horizontal) with the two tweeters clustered together. You will get far better sound than what you are currently doing.


Feel free to continue your (seemingly never ending) argument against it. I get your text books say it isn't a good idea (I have never been one to go by the books), and your expierience is that it doesn't sound as good. This is my experience & system and I don't need your approval.

Then why in the hell did you come here reporting what you have done? Did you come here expecting a co-signer to your madness?

Alright, so everyone, just throw away years and years of acoustical knowledge and experimentation done in labs under controlled conditions. Forget the white papers that have been submitted to AES on small room acoustics and speaker/room interactions. Forget the white papers on wave propagation, and driver interaction. What do the books and white papers know, anything goes and there are no rules. I will place my center speaker behind me, my left and right rears in front of me, and my main fronts to the side and rear of the listening area. This ought to sound great, because its my experience, and my system. Oh, and I will put my sub on the ceiling in the center of the room. It ought to have the perfect frequency response there.


I am always tinkering with my system. I will keep it like this for a while, I may change back at some point, especially if I get the M-Csi matching center for my M-3si's I have been looking for the right deal on, but I am very happy with the sound currently.

Thanks again,
Brad

If you are happy, I say more power to ya:cornut:

Mr Peabody
08-02-2010, 07:32 PM
Pix, don't start that frequency cancelling crap again, I can't believe the last time we went through this you didn't learn anything. Well, obviously, it must be true. I will say this just once and will not go through it again posting endless links to articles to prove it to you.
In general:
1. When same frequencies meet that are IN PHASE, they will increase.
2. When same frequencies meet that are OUT OF PHASE, they will cancel each other.

Mr Peabody
08-02-2010, 07:50 PM
Keep in mind that one larger woofer does not have the same negative side effects as using four spaced ones. If you are going to use four woofers, there has to be some way for them to couple together to effectively move more air as one driver(proximity boost). Spaced apart coupling is not effective, clustered together tightly it is. If you have ever seen a subwoofer in an IMAX installation, it has four 15" in what is called a "diamond cluster", a tight diamond shape pattern which causes the four 15" drivers to move the air as one large
driver.

One of the recommended ways to use dual subs is one in front of the room and one in the back of the room, so it would seem distance, as it relates to low frequencies, as in your example, isn't that relevant.

If you really want to move more air, you get a larger center channel with larger drivers, not two separate speakers in the name of moving more air. Let's be logical here, just how much more air is going to be moved with those small drivers in such a small cabinet like the OP has. If


Well, being logical, if you start with two drivers and add two more, you should effectively double the air movement.

What about the "phantom center channel"? I understand you are using two left/right speakers to create the phantom but those signals designated as center content have to be mono in order to be centered in the middle of the sound stage. Is there some reason this works horizontally and not vertically?

Mr Peabody
08-02-2010, 08:06 PM
:o
Keep in mind that one larger woofer does not have the same negative side effects as using four spaced ones. If you are going to use four woofers, there has to be some way for them to couple together to effectively move more air as one driver(proximity boost). Spaced apart coupling is not effective, clustered together tightly it is. If you have ever seen a subwoofer in an IMAX installation, it has four 15" in what is called a "diamond cluster", a tight diamond shape pattern which causes the four 15" drivers to move the air as one large
driver. If

Oh, I get it now, two centers isn't enough, he needs four, in a diamond shape around his TV, one on top, one underneath, and one on each side! diamond......

brad1138
08-02-2010, 08:36 PM
If this were the case, then you should have known that what you are trying is not a good idea at all. A hobbyist or a salesman probably knows about as much about room acoustics and wave interaction as I know about rocket science. None of these amateurish credentials validates any special knowledge when it comes to the proper way of setting up a home theater.

You are so full of yourself it is sickening. You can't for a second concede that your beliefs may no be 100% correct. Don't try to tell me what I do and don't know. For instance I know you are a know it all ass hole.

Why did I share this? I did something and liked the results and wanted to share that. You have spent all your efforts telling me I am wrong and don't know what I am hearing or talking about. I don't care how much knowledge you think you have, you can't tell me what I hear.

You have presented your position as if it is "gospel" with no wiggle room. I have found arguments for the other side, but you won't even acknowledge they exist. NOTHING is ever black and white, there is always some gray area, but you wont acknowledge that for a sec. I am done having discussions with people who wont do anything other than shout from their pulpit and not shut up.

I have never ran across a bigger group of Ditto heads (with a couple exceptions) that can't think outside the box. Take your theories and shove them you know where. I am going to enjoy my HT.

pixelthis
08-03-2010, 09:10 AM
You are so full of yourself it is sickening. You can't for a second concede that your beliefs may no be 100% correct. Don't try to tell me what I do and don't know. For instance I know you are a know it all ass hole.

Why did I share this? I did something and liked the results and wanted to share that. You have spent all your efforts telling me I am wrong and don't know what I am hearing or talking about. I don't care how much knowledge you think you have, you can't tell me what I hear.

You have presented your position as if it is "gospel" with no wiggle room. I have found arguments for the other side, but you won't even acknowledge they exist. NOTHING is ever black and white, there is always some gray area, but you wont acknowledge that for a sec. I am done having discussions with people who wont do anything other than shout from their pulpit and not shut up.

I have never ran across a bigger group of Ditto heads (with a couple exceptions) that can't think outside the box. Take your theories and shove them you know where. I am going to enjoy my HT.


GOOD for you!!!
Look, if your funds are limited, then its especially important to do the best with what you have.
I HAVE A 300 dollar center in the closet, other stuff I hardly use, but it doesnt fit into my system, anyway, you can't expect everybody to be enthusiastic with your setup when
its basically set up wrong .
Look at it this way, if it sounds this good now, how do you suppose it will sound decently
installed? Some have gone years doing the wrong thing, then they start doing the right thing and are amazed.
All I AM SAYING (hopefully a little more nicely than talks a lot) is that there is an optimum
way of setting up your gear, you are pissed because you think you had something you
created, and not only have others heard of it, they think its a bad idea.
Glad you enjoy your system, maybe someday when you get it set up correctly you
will see that there is an optimum way of doing things, and your way wasn't it.:1:

Sir Terrence the Terrible
08-03-2010, 09:44 AM
You are so full of yourself it is sickening. You can't for a second concede that your beliefs may no be 100% correct. Don't try to tell me what I do and don't know. For instance I know you are a know it all ass hole.


You are so full of ignorance it is sickening as well. No, my beliefs are 100% correct, and there is a mountain of evidence that proves this( I linked just one example that you stupidly ignored). Yes, I am an ass hole, but I am an educated one instead of just a stupid one like you are. I don't need to tell you what you don't know, this is as obvious as the big beak on your face.


Why did I share this? I did something and liked the results and wanted to share that. You have spent all your efforts telling me I am wrong and don't know what I am hearing or talking about. I don't care how much knowledge you think you have, you can't tell me what I hear.

I can't tell you what you can hear, I can tell you just can't hear. What you really wanted is a co-signer to your stupidity, and now you are mad that there isn't one.


You have presented your position as if it is "gospel" with no wiggle room. I have found arguments for the other side, but you won't even acknowledge they exist. NOTHING is ever black and white, there is always some gray area, but you wont acknowledge that for a sec. I am done having discussions with people who wont do anything other than shout from their pulpit and not shut up.


Where are these arguments, I would like to see it as you have not shown them here. You opinion does not count, because it is an opinion of justification and nothing more. There are some grey areas, but you are not in one, you are in a red area, and my link has proven that. If you are done having discussions about the bit of stupidity your have create, good, because I am done hearing about it. Let the door hit ya......


I have never ran across a bigger group of Ditto heads (with a couple exceptions) that can't think outside the box. Take your theories and shove them you know where. I am going to enjoy my HT.

So you think you are thinking outside the box? Well, what a waste of time. What's in the box are tools on how to properly set up your speakers, how to properly calibrate them, and how to integrate your system with your room to enhance its performance. So the box has every tool you need, so there is no need to re-invent the wheel with a square shape instead of a round one, the research has already been done.

Go enjoy your H, as you have yet to get to the T part.

bobsticks
08-03-2010, 09:47 AM
Now, now characters...this has been an interesting and informative conversation that I would like to see continue...but let's all take a deep breath and take it easy with the name calling.

Sir Terrence the Terrible
08-03-2010, 10:05 AM
Well, being logical, if you start with two drivers and add two more, you should effectively double the air movement.

That only works if they are clustered together tight enough to get a proximity gain. Spaced woofers may give the speaker better power handling, but it does not effectively double the movement of air, especially not with the woofers the size the OP has.


What about the "phantom center channel"? I understand you are using two left/right speakers to create the phantom but those signals designated as center content have to be mono in order to be centered in the middle of the sound stage. Is there some reason this works horizontally and not vertically?

Actually, you do experience cancellation when using a phantom center channel. One of the main things that THX found out when developing the criteria for THX, was that phantom imaging of dialog produced a diffusive effect that contributed to dialog intelligibility issues when other signals where present in the L/R speakers. This comes from a head related transfer distortion between 1-4khz which is eliminated by including a hard center speaker. In music, we usually eq to counter the effect on vocals that are mixed phantomly.

Sir Terrence the Terrible
08-03-2010, 10:06 AM
:o

Oh, I get it now, two centers isn't enough, he needs four, in a diamond shape around his TV, one on top, one underneath, and one on each side! diamond......

Ahhhh no!

E-Stat
08-03-2010, 10:31 AM
Other than the obvious benifit of the vocals coming from the TV rather than below it, they come across more powerful and more full, giving the effect of a much larger spk, I am really pleased with the results.
There is always a challenge with the center channel in a home theater arrangement where the speakers cannot play through an acoustically transparent screen and be suitably large and well placed. With most home systems, they must either be placed either above or below the screen or monitor, neither of which is necessarily ideal with creating a lifelike image. Your solution seems to address that image size factor but as has been pointed out, involves the compromises of comb filtering. You might actually consider disconnecting one of the tweeters to minimize that effect. You would then have a pseudo MTM arrangement. In my situation, the horizontally oriented MTM center is placed below a 61" monitor and aimed slightly upwards. That works ok, but there is still a sense of listening down to dialogue.

Each of us has their own preferences and the compromises with which we are most comfortable.

rw

pixelthis
08-04-2010, 09:59 AM
Now, now characters...this has been an interesting and informative conversation that I would like to see continue...but let's all take a deep breath and take it easy with the name calling.

Party pooper.:1:

Sir Terrence the Terrible
08-04-2010, 11:19 AM
There is always a challenge with the center channel in a home theater arrangement where the speakers cannot play through an acoustically transparent screen and be suitably large and well placed.

That challenge was conquered long ago when the ITU-775 standards were introduced.



With most home systems, they must either be placed either above or below the screen or monitor, neither of which is necessarily ideal with creating a lifelike image.

The way our ear/brain works, it will associate the dialog right on screen as long as there are no huge dis-association of the speaker from the screen(like it being placed wide left or right of the screen). If he sat his center speaker on top of the television(with an aim downward toward the listener) the dialog will be associated towards the screen. If he put it below the screen and aimed it up towards the listening position, the dialog will be associated with the screen. If you raise the screen so the bottom of it is at eye level when seated, place the speaker on a stand in front of the television so it is near ear height, this would be a perfect solution for the association of the dialog coming directly from the screen. The OP's set up has the dual center channel in a cove under the television(can anyone say early reflections and cavity resonance). What he did was place aesthetics over performance. Nothing more.


Your solution seems to address that image size factor but as has been pointed out, involves the compromises of comb filtering. You might actually consider disconnecting one of the tweeters to minimize that effect. You would then have a pseudo MTM arrangement. In my situation, the horizontally oriented MTM center is placed below a 61" monitor and aimed slightly upwards. That works ok, but there is still a sense of listening down to dialogue.

Each of us has their own preferences and the compromises with which we are most comfortable.

rw

In one of my rooms the center speaker sits 7" below the screen, but on a 30" stand. I have never had the impression that dialog was coming from anywhere but the screen. But of course, my center channel is vertically oriented, and that might make a difference.

Dual-500
08-04-2010, 11:34 AM
Guys this is a good lively discussion for sure. I hadn't posted for a few years on AR - went into the computers/forums a couple of years and as of late have been on the car forums as I have a hotrod / daily driver I have been working for the past couple of years restoring and such.

Currently looking for some technical materials to support my discussion and viewpoints on this thread & topic.

A little history is warranted:

I didn't post to troll and start a flame-a-thon. My original intent for logging on to AR was for discussion on Center Channel usage or not. I have been considering using phantom mode and doing away with the center all together - did some A/B listening with phantom mode routing center signals to L&R mains. Center is active in my current setup as are L&R mains. It sounds different between the two modes, sounds good in both modes, but at this point I prefer using the system with center in the movie mode.

The difference got me wondering. Hardware is identical in L&R mains and center with the exception of the midrange horn in center -vs- horns used in L&R mains. Both use the same dual 8" drivers for low mids and same mid drivers on the horns as well as the same HF driver/horn. Crossover is bit different with L&R mains being full digital which allows for complete time correction while the center only allows for time correction between low mid 8's and mid horn.

BTW, I just eq'd it after a change out of the equalizer. Went from parametric to 1/3 octave graphic and back to parametric.
-----------------------------------------------------------------------------------------------------------------------------

* I'll find the technical material and continue the discussion regarding using dual discrete centers in the next day or so.

Intensity is high, let's not forget we're all hobbyists and treat one another respect - and respect one another's ideas.

To be continued........gotta dial into a telecon for work.

Cheers my hifi brothers!!!! :18:

Dual-500
08-04-2010, 12:11 PM
Now, now characters...this has been an interesting and informative conversation that I would like to see continue...but let's all take a deep breath and take it easy with the name calling.
Absolutely agreed. The insults are flying - I probably need to go back and re-read some of my posts for qustionable comments.

And honestly, there's good discussion to be had here.

E-Stat
08-04-2010, 12:53 PM
That challenge was conquered long ago when the ITU-775 standards were introduced...the dialog will be associated towards the screen. If he put it below the screen and aimed it up towards the listening position, the dialog will be associated with the screen.
*Associated", perhaps. I prefer the IMAX approach where the fronts and center share the same vertical plane. One of Tomlinson's demos uses the same approach. Look here at Figure 1. (http://www.huonlabs.com/download/AA_01_surround.pdf)


The OP's set up has the dual center channel in a cove under the television(can anyone say early reflections and cavity resonance).
While his photos suggests a single center (likely taken before the change), his description does not. I refer to this: "I have 1 S1 upright below the TV and the other upside down above it. " Above and below screen. Which centers the image as one finds in theatres.

rw

Mr Peabody
08-04-2010, 04:19 PM
SteveW, you didn't post your equipment in your profile, what do you have?

PeruvianSkies
08-04-2010, 06:34 PM
You are some of the few around here that understand that listening to a system is more than just numbers and graphics, that it is an emotional experience that involves many of our senses and evokes something special inside us, something we wish to replicate time and time again with our music.

Thank you both for your contributions around here.

Sir Terrence the Terrible
08-05-2010, 08:47 AM
*Associated", perhaps. I prefer the IMAX approach where the fronts and center share the same vertical plane. One of Tomlinson's demos uses the same approach. Look here at Figure 1. (http://www.huonlabs.com/download/AA_01_surround.pdf)


I was a student of Tomlinson when he was working on the 10.2 system. I heard that system a lot while in school. What you don't see from that picture is that the center speaker is NOT on the same plane, it is actually pushed back a bit so that it is physically aligned(by distance) with the L/R mains to the listening seat. He is actually augmenting the ITU-B775 setup with additional points in space to create more envelopment, and more directional capabilities.

The IMAX system uses electronic delay to line up its speakers for equidistant placement. With this delay, it allows the IMAX front speakers to project a singular acoustical wave when projecting sound to the audience. The "voice of god" speaker on top of the screen uses that same delay to align its output with the other front speakers.



While his photos suggests a single center (likely taken before the change), his description does not. I refer to this: "I have 1 S1 upright below the TV and the other upside down above it. " Above and below screen. Which centers the image as one finds in theatres.

rw

Theaters don't use two speakers, and this is still a poor practice for all of the reasons I outlined. You don't need two center speaker to center the image, our ear/brain already does this work. With this setup, he now has timing issues to deal with along with the other issues I outlined, as he will be hearing those two spaced speaker output hitting his ears at two different times. Now you must know that having the output of two speakers with the same information hitting the ears at two different times is not going to be great for the dialog. It will sound smeared and diffused. His television is not tall enough that he really needs two centers, I have a 65" that does not need two center to focus the dialog on the screen. I just placed the center speaker just below the bottom of the screen, and my ears and brain do the rest.

This is a poor practice no matter how you slice or dice it.

pixelthis
08-05-2010, 09:22 AM
Guys this is a good lively discussion for sure. I hadn't posted for a few years on AR - went into the computers/forums a couple of years and as of late have been on the car forums as I have a hotrod / daily driver I have been working for the past couple of years restoring and such.

Currently looking for some technical materials to support my discussion and viewpoints on this thread & topic.

A little history is warranted:

I didn't post to troll and start a flame-a-thon. My original intent for logging on to AR was for discussion on Center Channel usage or not. I have been considering using phantom mode and doing away with the center all together - did some A/B listening with phantom mode routing center signals to L&R mains. Center is active in my current setup as are L&R mains. It sounds different between the two modes, sounds good in both modes, but at this point I prefer using the system with center in the movie mode.

The difference got me wondering. Hardware is identical in L&R mains and center with the exception of the midrange horn in center -vs- horns used in L&R mains. Both use the same dual 8" drivers for low mids and same mid drivers on the horns as well as the same HF driver/horn. Crossover is bit different with L&R mains being full digital which allows for complete time correction while the center only allows for time correction between low mid 8's and mid horn.

BTW, I just eq'd it after a change out of the equalizer. Went from parametric to 1/3 octave graphic and back to parametric.
-----------------------------------------------------------------------------------------------------------------------------

* I'll find the technical material and continue the discussion regarding using dual discrete centers in the next day or so.

Intensity is high, let's not forget we're all hobbyists and treat one another respect - and respect one another's ideas.

To be continued........gotta dial into a telecon for work.

Cheers my hifi brothers!!!! :18:


Your center needs to match your left-right speakers as closely as possible, sometimes three identical speakers are used.
ALSO, the center is the most important speaker, up to 90% of teh sound comes out of it,
you can get by without one, but its not recommended.
And you still don't get it, its not a matter of "respect" for ideas, dual centers is
the wrong way to do it, period.
I HAVE PLENTY OF RESPECT FOR YOU, but if you're jumping out of the plane without
a chute, its incumbent upon me to point it out to you, is all.
There is a certain way of doing things sometimes, its not a matter of opinion.
Sometimes several ways of doing things...but not this time.
One center is all you need ...PERIOD.
You need more "spread", get a bigger center, they make some pretty large.:1:

E-Stat
08-05-2010, 09:44 AM
What you don't see from that picture is that the center speaker is NOT on the same plane, it is actually pushed back a bit so that it is physically aligned(by distance) with the L/R mains to the listening seat.
When I speak of the vertical plane, I refer to the height of the mains vs. the center. It sure appears from the picture that the center and fronts use the same stands. Elbow height is the same for both center and right speaker.


The IMAX system uses electronic delay to line up its speakers for equidistant placement. With this delay, it allows the IMAX front speakers to project a singular acoustical wave when projecting sound to the audience. The "voice of god" speaker on top of the screen uses that same delay to align its output with the other front speakers.
Ok. My point is that they are not found below or above the screen. They are located in the same vertical plane as you see with the guys in the 10.2 photo - albeit they are a tad larger. :)


Theaters don't use two speakers, and this is still a poor practice for all of the reasons I outlined.
Consistent vertical alignment eliminates the need for separate speakers. Having a monitor in the middle, however, changes the equation. Neither above nor below is ideal.


I have a 65" that does not need two center to focus the dialog on the screen. I just placed the center speaker just below the bottom of the screen, and my ears and brain do the rest.
My brain is not as convincingly fooled with a similar arrangement which is why I continue to prefer the IMAX approach. The image is not consistent across the stage with the staggered vertical approach required by most home theaters.

rw

Sir Terrence the Terrible
08-05-2010, 09:56 AM
When I speak of the vertical plane, I refer to the height of the mains vs. the center. It sure appears from the picture that the center and fronts use the same stands. Elbow height is the same for both center and right speaker.

Then you are correct.


Ok. My point is that they are not found below or above the screen. They are located in the same vertical plane as you see with the guys in the 10.2 photo.

You are right, but they are not supporting video either.


Consistent vertical alignment eliminates the need for separate speakers. Having a monitor in the middle, however, changes the equation. Neither above nor below is ideal.

Not necessarily. Both above and below are perfectly acceptable as long as the speaker is vertically oriented. As I stated before, if you place the television so the bottom of the screen is at eye level, then you can place the center speaker so its top is aligned with the bottom of the television (very few folks use monitors, they have no speakers or tuners). That is below the television, and I have never heard this setup dis-associate the dialog from the screen.

THX has found that you can have the maximum of 16" of displacement between the tweeters of the center speaker and L/R mains before you start noticing an image jumping. So they allow that much offset even in THX approved set ups. The ear/brain is terrific at associating the dialog with the screen as long as you don't violate that 16" rule



My brain is not as convincingly fooled with a similar arrangement. I continue to prefer the IMAX approach.

rw

You also use a horizontal center speaker, that is a problem in and of itself.
A nice healthy floor interaction will give away a location of a speaker pretty quickly. Aside from that, the IMAX approach does not use dissimilar front speakers. They are all the same, and are oriented the same.

E-Stat
08-05-2010, 11:11 AM
You are right, but they are not supporting video either.
True, but they are illustrating the ideal relationship.


That is below the television, and I have never heard this setup dis-associate the dialog from the screen.
Ok. I find such misalignment somewhat distracting.


THX has found that you can have the maximum of 16" of displacement between the tweeters of the center speaker and L/R mains before you start noticing an image jumping.
That is an interesting parameter. In my case that would place the mains tweeters at a height of no more than 30.5" and they are substantially higher now. Practically speaking, that would mean I would just place the mains on top of the subs since I have no latitude with the center's vertical placement. I'll try that approach, but having been accustomed to full height line sources for thirty some years, I really don't like listening "down" to the sound field. Thanks for the tip in any case.


You also use a horizontal center speaker, that is a problem in and of itself.
Yet another HT compromise dictated by practicality.


They are all the same, and are oriented the same.
It's back to that concept of using the same vertical plane - which is not commonly found with HT systems, hence my original comment about the obvious challenges.

rw

Sir Terrence the Terrible
08-05-2010, 02:53 PM
True, but they are illustrating the ideal relationship.

For music sources at the moment, he has never applied his concept to real world video environments. At this moment THX is the only source that has applied its concepts to real world video and film environments - hence why its standards are applied in most HT pre-pro's, and receivers whether THX certified or not.



Ok. I find such misalignment somewhat distracting.

You have a horizontal center speaker, I don't. That probably accounts for the difference of opinion.


That is an interesting parameter. In my case that would place the mains tweeters at a height of no more than 30.5" and they are substantially higher now. Practically speaking, that would mean I would just place the mains on top of the subs since I have no latitude with the center's vertical placement. I'll try that approach, but having been accustomed to full height line sources for thirty some years, I really don't like listening "down" to the sound field. Thanks for the tip in any case.

Remember, this parimeter does not have anything to do with the height of any speaker, but the difference in distance between the center axis of the tweeters in the center and L/R mains. This also represents a worst case scenario, which would seem extreme to me in most enthusiasts home theaters.

Once again, that may be a case of difference of orientation of the center speaker. You aim your horizontally oriented speaker upwards (with its wide vertical dispersion pattern), and you get a little less floor bounce, and a little more ceiling bounce. I aim mine upwards(with its narrow vertical dispersion pattern), and it directs more energy to my ears, without really changing its reflection relationship between the floor and ceiling, or the side walls. Aiming my center upwards has the advantage of offsetting the difference in height that the center and L/R tweeters have (4" difference). That might be why we have a difference in perspectives - there may be other reasons as well.



Yet another HT compromise dictated by practicality.

Agreed. Its all a balance between ideal and compromises dictated by circumstances.



It's back to that concept of using the same vertical plane - which is not commonly found with HT systems, hence my original comment about the obvious challenges.

rw



This is a hard comment to make. Nobody has done research into how most folks orient their center speaker in relationship to their L/R mains in the vertical plane - or quite frankly calibrate or align their systems, so this statement might fail under more careful scrutiny. However, on some level you might be right. The original poster decided it was time to make new rules concerning wave propagation in small rooms, and take very generous liberties in regards to a great many tried and true HT placement concepts, that on this level you may be spot on.

The vertical plane is only a third of the equation - simular radiation pattern, and simular speaker is the other. One out of three ain't bad, but it is no cigar either.

E-Stat
08-05-2010, 03:29 PM
For music sources at the moment...
And the way the IMAX theaters are configured.


Remember, this parimeter does not have anything to do with the height of any speaker, but the difference in distance between the center axis of the tweeters in the center and L/R mains.
The simple concept was clear. When one speaker's vertical position cannot be moved, however, then any variation must necessarily occur with the other. I cannot raise the center's position.


That might be why we have a difference in perspectives - there may be other reasons as well.
There are. I prefer symmetric and coherent imaging.


This is a hard comment to make. Nobody has done research into how most folks orient their center speaker in relationship to their L/R mains in the vertical plane - or quite frankly calibrate or align their systems, so this statement might fail under more careful scrutiny.
Do you believe that IMAX and other cinemas who have the luxury of placing the center at the same vertical plane as the fronts do that for no deliberate reason?


The original poster decided it was time to make new rules concerning wave propagation in small rooms, and take very generous liberties in regards to a great many tried and true HT placement concepts, that on this level you may be spot on.
Or, choice "B", demonstrates different priorities among imperfect choices.

rw

Mr Peabody
08-05-2010, 05:01 PM
I listened to phantom center before and to me it doesn't compare to having an actual center. Can't explain why, but it defintely sounds better with a center channel speaker.

I have one of those twin tower entertainment centers with a bridge. When I had my old school rear projection TV my center sat on the bridge that went across the top of the TV. I had to work to associate the sound with the center screen. When I got my DLP I spread the towers and took the bridge out. The center went under the TV. The imaging was much better and the sound naturally seemed to be coming from the center screen. I believe the improvement was two fold, first it may be what Sir T was talking about with the center tweeter being closer aligned to the mains tweeter, and in each position the center fired forward, on top it just sat flat and on bottom there's not enough room to tilt up, so when it was on top I think more went over my head than in my ears, on bottom the center still fires forward but the sound can only go up and it's closer to my face. Like you all say each set up is different with it's own unique issues but unless your mains are tall with tweeters on top I think one is probably better with a center at bottom of screen. I guess ideal would be screen mounted on wall to where all three fronts could be same height.

PSkies, thanks for the kind words.

Sir Terrence the Terrible
08-05-2010, 05:39 PM
And the way the IMAX theaters are configured.

And so are THX certified theaters and every other movie theater in the world.



The simple concept was clear. When one speaker's vertical position cannot be moved, however, then any variation must necessarily occur with the other. I cannot raise the center's position.

Exactly!



There are. I prefer symmetric and coherent imaging.

We don't differ here. How do you achieve that with a front sound stage with two different radiation patterns?



Do you believe that IMAX and other cinemas who have the luxury of placing the center at the same vertical plane as the fronts do that for no deliberate reason?

You weren't speaker of theaters, you said this

It's back to that concept of using the same vertical plane - which is not commonly found with HT systems, hence my original comment about the obvious challenges.

How did you get from HT systems to theaters with your comments?




Or, choice "B", demonstrates different priorities among imperfect choices.

rw

Or unnecessary compromises when their are better choices.

E-Stat
08-05-2010, 07:21 PM
And so are THX certified theaters and every other movie theater in the world.
And theatres at the moment, too.


We don't differ here. How do you achieve that with a front sound stage with two different radiation patterns?
How do you achieve a realistic image with a staggered center? Certainly, such is not tolerated at an IMAX.


You weren't speaker of theaters, you said this
As for me, I use the same criteria for home theatres as well as - theatres!


How did you get from HT systems to theaters with your comments?
???


Or unnecessary compromises when their are better choices.
Such are value judgements not shared by everyone. Clearly when it comes to speakers, there is hardly one size that fits all. :)

rw

Dual-500
08-05-2010, 07:51 PM
I listened to phantom center before and to me it doesn't compare to having an actual center. Can't explain why, but it defintely sounds better with a center channel speaker.

I have one of those twin tower entertainment centers with a bridge. When I had my old school rear projection TV my center sat on the bridge that went across the top of the TV. I had to work to associate the sound with the center screen. When I got my DLP I spread the towers and took the bridge out. The center went under the TV. The imaging was much better and the sound naturally seemed to be coming from the center screen. I believe the improvement was two fold, first it may be what Sir T was talking about with the center tweeter being closer aligned to the mains tweeter, and in each position the center fired forward, on top it just sat flat and on bottom there's not enough room to tilt up, so when it was on top I think more went over my head than in my ears, on bottom the center still fires forward but the sound can only go up and it's closer to my face. Like you all say each set up is different with it's own unique issues but unless your mains are tall with tweeters on top I think one is probably better with a center at bottom of screen. I guess ideal would be screen mounted on wall to where all three fronts could be same height.

PSkies, thanks for the kind words.
Sounding better with center - yes. So far with limited testing that's the case in my setup also.

Center and L&R mains are identical with the exception of the horn/lens flare on the center being larger. Differences in 1" throat midrange compression drivers is nominal at best - all have phenolic diaphragms. Vertical orientation of high mid horns is within 6". I can't attribute the difference in sound to the diffierence in the mid horn/lens flare.

I just retuned the center with the change of the eq from graphic to parametric. Haven't checked the L&R mains for tuning, but will do so soon as a crossover change is pending for L&R mains.

Seems like it's both point source localization and overall tone. The center seems to eq differently than do the L&R mains - or simply is eq'd differently - or both. I haven't looked into that yet. Both L&R mains and center have parametric eq.

Center sits a little behind the L&R mains due to mock up setup. That may account for some of the tuning difference - not sure at this point. The mid horns on the L&R mains are nominal 80 degree horizontal coverage as I recall (McCauley 416 horn/lens) while the center is around 120 degrees horizontal if memory serves me correctly (McCauley 455 horn/lens). The final system configuration will have JBL 2390 horn/lens with JBL 2482 compression drivers.

Physically the L&R mains sit about 32" in front of the center, but are electronically corrected to align with the sub which is ~12" ahead of the center.

Again, the setup is in a temporary mock up condition as it has been morphing the past couple of years. I think I've arrived at the final configuration and have all the components.

Time for some cabinet work.

Center is flying, 46" monitor sits beneath center speaker, on top of sub for now. System corner loads into room. When completed, the center and L&R mains will also be flown, with sub remaining on the floor.

I'm interested in tuning experiences and any differences noted between center and L&R mains in tuning - for setups with closely matched centers and L&R mains.

Dual-500
08-05-2010, 08:16 PM
1) Your center needs to match your left-right speakers as closely as possible, sometimes three identical speakers are used.
2) ALSO, the center is the most important speaker, up to 90% of the sound comes out of it, You can get by without one, but its not recommended.
3) And you still don't get it, its not a matter of "respect" for ideas, dual centers is
the wrong way to do it, period.
4) I HAVE PLENTY OF RESPECT FOR YOU, but if you're jumping out of the plane without a chute, its incumbent upon me to point it out to you, is all.
5) There is a certain way of doing things sometimes, its not a matter of opinion.
6) Sometimes several ways of doing things...but not this time.
7) One center is all you need ...PERIOD.
8) You need more "spread", get a bigger center, they make some pretty large.:1:
1) I agree with that and have arrived at that conclusion myself as a matter of system evolution the past 10 years or to.
2) Agree here too - it seems to sound better coming from the center in my system.
3) Respect is respect. Differences can be tactfully stated or just blasted out as blatent crude insults.
4) Same here. I don't see any differences in this hobby the same as jumping out of an airplane - maybe I'm missing something. For me this is a hobby and these forums as well as others are a way to interacty with other hobbyists. A place to share ideas and learn from one another.
5) Sometimes. However, this hobby is as much an art as it is a science. And we all learn as we progress and our systems generally evolve as we do - many times in step with our learning. Other times, compromises are made due to factors such as budget, etc. In the case of my setup it's just in a mock up condition for now. L&R mains and center and sub are not aligned on the horizontal axis - a little electronic correction is in place - but it's not the "Anal Correct" setup - so what? It doesn't suggest I"m not aware of that. I doesn't suggest I"m not aware of potential or real side effects. Know what I mean?
6) Agreed, it's not always cut and dried, "Right" -vs- "Wrong", "Correct" -vs- "Incorrect". There is something to say for dual centers. Perhaps he's wants to hit a sofa and love seat on opposite sides of the room on a budget already has a pair of suitable speakers.
7) Not always, not in every case. Yes, we can custom design for unique coverage on the horizontal axis or in some cases simply splay out two enclosures. Whatever the condition, the language in parts of this thread is not warranted.
8) Yes and I've addresed this in 6 & 7. But, yes bigger is better and for optimum results, the vertical and horizontal dispersion should properly fit the environment.

Some of the language in this thread is pretty harsh - references to smoking crack, things being referred to as stupid. Uecessary and certainly isn't reflective of any degree of respect as I understand it to be. That isn't pointed your way.

Now, let's talk about center channel loudspeakers!

Dual-500
08-05-2010, 08:46 PM
SteveW, you didn't post your equipment in your profile, what do you have?
Goodness. What I am running is a mock up of the final configuration. Posted in profile - too busy smoking crack as of late to post. May do so in the future.

Right now the center and L&R mains are JBL 4612's modified for active amplification and crossovers and also sporting high midrange horns. It's a list of stuff. Amps are Carver and Adcom - I think it was 13 or 15 discreet channels of amplification between HT system and house system. JBL 2245 18" sub with a Carver TFM-35x amp bridged mono driving it. There's a AV-705x in there too driving low mids for the center & L&R mains and rears. Ashly signal processing for parametric eq & limiters, with DBX DriveRack crossovers on the mains and a Samson on the center. Parametric eq on center L&R mains. No eq on rears for now - considering that. Seeking feedback on that topic. Carver TFM-6CB on the L&R HF.

Final configuration L&R mains will be dual JBL 2206 12's, JBL 2390 horn/lens w/JBL 2482 drivers on them and a pair of JBL 2404 biradial HF horn/drivers. The sub will be 4 x JBL 2445 18's. Phase LInear Dual-500 will drive the subs and Carver's the top end.

Here's a pic of the current rack - going to migrate into slightly larger rack with front and back doors when I reconfigure the amp rack.

Dual DirecTV high def receivers, one has DVR capability the other is for background music. House system is the 4 ch Adcom amp driving JBL S-38's, a pair of Bose 301's in the shop (I don't want to hear a peep about the Blose in the shop as they were junk I was given and work fine out there) and many Optimus Pro LX5' s throughout the house.

Yamaguchi (aka Yamaha) DVD player.

EDIT: Also have a 42" LCD in the shop that is viewable from covered patio with shop door open.
Usage profile for the system is mainly TV in 2ch stereo mode. Most TV is watched with only the Adcom running the house system, the JBL S-38's are flying in the HT room and sound fine for TV. Discovery channel, Learning channel, History channel, Spike, Versus, Speed channel and such, about 90% of which is pre-recorede on the DVR receiver. I don't watch a lot of movies - but, do from time to time.

Oh yeah, it's on a dedicated 20a circuit with a dedicated #8 stranded copper ground wire from cold water system.

Here's a pic of the current rack setup.

System tuning is accomplished using a Samson D-1500 RTA.

http://www.senorpanadero.net/uploader/userfiles/stevew/HT%20Rack%208-5-2010.jpg

PeruvianSkies
08-05-2010, 09:18 PM
Goodness. What I am running is a mock up of the final configuration. Posted in profile - too busy smoking crack as of late to post. May do so in the future.

Right now the center and L&R mains are JBL 4612's modified for active amplification and crossovers and also sporting high midrange horns. It's a list of stuff. Amps are Carver and Adcom - I think it was 13 or 15 discreet channels of amplification between HT system and house system. JBL 2245 18" sub with a Carver TFM-35x amp bridged mono driving it. There's a AV-705x in there too driving low mids for the center & L&R mains and rears. Ashly signal processing for parametric eq & limiters, with DBX DriveRack crossovers on the mains and a Samson on the center. Parametric eq on center L&R mains. No eq on rears for now - considering that. Seeking feedback on that topic. Carver TFM-6CB on the L&R HF.

Final configuration L&R mains will be dual JBL 2206 12's, JBL 2390 horn/lens w/JBL 2482 drivers on them and a pair of JBL 2404 biradial HF horn/drivers. The sub will be 4 x JBL 2445 18's. Phase LInear Dual-500 will drive the subs and Carver's the top end.

Here's a pic of the current rack - going to migrate into slightly larger rack with front and back doors when I reconfigure the amp rack.

Dual DirecTV high def receivers, one has DVR capability the other is for background music. House system is the 4 ch Adcom amp driving JBL S-38's, a pair of Bose 301's in the shop (I don't want to hear a peep about the Blose in the shop as they were junk I was given and work fine out there) and many Optimus Pro LX5' s throughout the house.

Yamaguchi (aka Yamaha) DVD player.

Here's a pic of the current rack.

System tuning is accomplished using a Samson D-1500 RTA.

http://www.senorpanadero.net/uploader/userfiles/stevew/HT%20Rack%208-5-2010.jpg


Looks like the inside of a 747 cockpit to me.... what do you do about heat issues?

Dual-500
08-05-2010, 10:46 PM
Looks like the inside of a 747 cockpit to me.... what do you do about heat issues?
Good question.

When doing the initial rack build up in late 2005 I was discussing cooling fans with a friend. He suggested using 12v computer fans. That was a great idea - cost is much cheaper than 120v AC fans and size and capacity chioces are much better. And, they can be easily speed controlled.

So, I bought a 12v 10a power supply, 4 computer fan speed controllers and use about a dozen computer fans - a mix of 120mm and 80 mm and keep the speed slowed down to keep noise in check. Some fans are mounted directly to the amps with RTV, four are on the sides of the rack beside the TFM-35x, and three 120mm are in a fan rack mount panel in the rear of the rack at the top to remove residual heat and keep DirecTV receivers cool. The rack also sits on the far side of the room from the main listening position so fans are essentially inaudible.

Next rack will have doors and air filters to control dust. Right now I have to vacuum it out about once a year to remove dust.

Sir Terrence the Terrible
08-06-2010, 01:26 PM
Goodness. What I am running is a mock up of the final configuration. Posted in profile - too busy smoking crack as of late to post. May do so in the future.

Right now the center and L&R mains are JBL 4612's modified for active amplification and crossovers and also sporting high midrange horns. It's a list of stuff. Amps are Carver and Adcom - I think it was 13 or 15 discreet channels of amplification between HT system and house system. JBL 2245 18" sub with a Carver TFM-35x amp bridged mono driving it. There's a AV-705x in there too driving low mids for the center & L&R mains and rears. Ashly signal processing for parametric eq & limiters, with DBX DriveRack crossovers on the mains and a Samson on the center. Parametric eq on center L&R mains. No eq on rears for now - considering that. Seeking feedback on that topic. Carver TFM-6CB on the L&R HF.

Final configuration L&R mains will be dual JBL 2206 12's, JBL 2390 horn/lens w/JBL 2482 drivers on them and a pair of JBL 2404 biradial HF horn/drivers. The sub will be 4 x JBL 2445 18's. Phase LInear Dual-500 will drive the subs and Carver's the top end.

Here's a pic of the current rack - going to migrate into slightly larger rack with front and back doors when I reconfigure the amp rack.

Dual DirecTV high def receivers, one has DVR capability the other is for background music. House system is the 4 ch Adcom amp driving JBL S-38's, a pair of Bose 301's in the shop (I don't want to hear a peep about the Blose in the shop as they were junk I was given and work fine out there) and many Optimus Pro LX5' s throughout the house.

Yamaguchi (aka Yamaha) DVD player.

EDIT: Also have a 42" LCD in the shop that is viewable from covered patio with shop door open.
Usage profile for the system is mainly TV in 2ch stereo mode. Most TV is watched with only the Adcom running the house system, the JBL S-38's are flying in the HT room and sound fine for TV. Discovery channel, Learning channel, History channel, Spike, Versus, Speed channel and such, about 90% of which is pre-recorede on the DVR receiver. I don't watch a lot of movies - but, do from time to time.

Oh yeah, it's on a dedicated 20a circuit with a dedicated #8 stranded copper ground wire from cold water system.

Here's a pic of the current rack setup.

System tuning is accomplished using a Samson D-1500 RTA.

http://www.senorpanadero.net/uploader/userfiles/stevew/HT%20Rack%208-5-2010.jpg

This is overkill for a HT for sure!!! You don't need 3/4 of this equipment to create a nice home theater.

As a person who does both live sound and home theater, if you approach home theater like a PA system, you will make an absolute mess of things.

E-Stat
08-06-2010, 01:43 PM
This is overkill for a HT for sure!!! You don't need 3/4 of this equipment to create a nice home theater.
On the other hand, it looks cool. Scroll down to take a look at what McIntosh uses in their demo room at the factory. I visited it once about two years ago.


Big Blue Racks (http://www.hometheaterhifi.com/volume_14_1/mcintosh-factory-tour-1-2007-part-2.html)

rw

Sir Terrence the Terrible
08-06-2010, 01:56 PM
1) 5) Sometimes. However, this hobby is as much an art as it is a science. And we all learn as we progress and our systems generally evolve as we do - many times in step with our learning. Other times, compromises are made due to factors such as budget, etc. In the case of my setup it's just in a mock up condition for now. L&R mains and center and sub are not aligned on the horizontal axis - a little electronic correction is in place - but it's not the "Anal Correct" setup - so what? It doesn't suggest I"m not aware of that. I doesn't suggest I"m not aware of potential or real side effects. Know what I mean?

I would not characterize a properly set up system as a "Anal Correct" set up. Like everything in life there is a right way to do things, and there is a wrong way. There is a ideal way, and a way the envolves some necessary compromises that have to be carefully made to accomodate a certain environment.


6) Agreed, it's not always cut and dried, "Right" -vs- "Wrong", "Correct" -vs- "Incorrect". There is something to say for dual centers. Perhaps he's wants to hit a sofa and love seat on opposite sides of the room on a budget already has a pair of suitable speakers.

As a THX and cedia certified installer(with emphasis on the sound half of the equation), there is a right way and a wrong way. There is a correct and incorrect way. As I have said above, there is an ideal way, and a way that envolves some compromises. You try to apply your compromises in a methodical way as to have a few negative consequences as possible.


7) Not always, not in every case. Yes, we can custom design for unique coverage on the horizontal axis or in some cases simply splay out two enclosures. Whatever the condition, the language in parts of this thread is not warranted.

The use of "coverage" in a home theater setting is unnecessary. The 5.1 or 7.1 provides enough channels for coverage in home theaters. Now if you have a very large theater or screening room with lots of seats, that is a different story altogether. You have examples you can take directly from movie theaters to tackle that issue.


8) Yes and I've addresed this in 6 & 7. But, yes bigger is better and for optimum results, the vertical and horizontal dispersion should properly fit the environment.

Sometimes bigger is not always better. You scale the sound system for the space.


Some of the language in this thread is pretty harsh - references to smoking crack, things being referred to as stupid. Uecessary and certainly isn't reflective of any degree of respect as I understand it to be. That isn't pointed your way.

Now, let's talk about center channel loudspeakers!

Some ideas I have seen around here are quite frankly stupid (this ideas is one of them). There is a huge home theater tool box that has answers for just about every HT situation
out there. There is absolutely no reason to try and re-invent the wheel when the one we have works very well right now.

You want better "coverage" get a speaker with a wider dispersion pattern, not two speakers. You want more power in the room, get a larger speaker and amp. When you start adding a bunch of speakers beyond the 5.1 or 7.1 setups, you run a huge chance of creating an acoustical nighmare that was completely unnecessary in the first place.

Sir Terrence the Terrible
08-06-2010, 01:58 PM
On the other hand, it looks cool. Scroll down to take a look at what McIntosh uses in their demo room at the factory. I visited it once about two years ago.


Big Blue Racks (http://www.hometheaterhifi.com/volume_14_1/mcintosh-factory-tour-1-2007-part-2.html)

rw

It is probably a very big theater that rack has to serve.

E-Stat
08-06-2010, 02:24 PM
It is probably a very big theater that rack has to serve.
It is, but there is a lot of redundancy with their components on display. It's all about the blue lights. The front speakers were powered by their 2 kW amps which are not even in the picture. I was not particularly impressed with the overall sound. Here's another of a private system where the light show is nearly as impressive. Note the horizontal center. Do you think that breaks the 16" rule? :) This system was reputed to cost $1M.

More blue lights (http://www.hometheaterdesignmag.com/prointeriors/207mc/)

As an aside, if you Google "McIntosh rack images", you'll find a handy link. There you'll find more of the same and... pictures of other kinds of *racks*. :)

rw

Mr Peabody
08-06-2010, 02:33 PM
Steve you have an elaborate system. Of course, from another thread I saw you and I differ on Carver :) I wouldn't think they'd put out enough heat to worry about. Have you ever thought of going with a digital amp like Nuforce? If all four subs will be in the same room that should be something to hear. I have some Pro sound background but we used EV and Shure for the most part, filled in with some other things and sold a lot of Bogen.

Dual-500
08-06-2010, 03:04 PM
This is overkill for a HT for sure!!! You don't need 3/4 of this equipment to create a nice home theater.

As a person who does both live sound and home theater, if you approach home theater like a PA system, you will make an absolute mess of things.
Well thank you for the nice critique! Laughing now my friend.

Which parts do you recommend I do away with to arrive at at nice 25% solution?

At what point did I stray from HT/music system into the realm of an absolute mess? Can you be a little more specific here "if you approach home theater like a PA system"? I'm not sure I understand what I've done with my system in terms of approach that could be considered "PA approach" and not "HIgh End HT/music" playback system approach. What am I doing in terms of system design or component selection that we wouldn't find in a real Theatre of present or past?

My career is currently in the mechanical engineering discipline for an aircraft manufacturing company and has been as such for a while. In the pro audio, theatre arena I'm degreed in Lighting and Sound design and have about equal working experience in reinforcement, institution sound and playback systems.

Dual-500
08-06-2010, 03:16 PM
On the other hand, it looks cool. Scroll down to take a look at what McIntosh uses in their demo room at the factory. I visited it once about two years ago.

Big Blue Racks (http://www.hometheaterhifi.com/volume_14_1/mcintosh-factory-tour-1-2007-part-2.html)
rw
Thank you.

Some of the design considetations in the system was to achieve a little old school sound. Mainly for the center. From the old days of the Altec Voice of the Theatre systems. I originally was considering a full horn loaded design for the center.

I ended up, for now anyway running dual 8's and chose a vintage McCauley horn/lens and vintage JBL 2410 compression driver that is modified by using a phenolic diaphragm from the JBL 2461/2470. Also using a JBL 2404 for the HF element. Considered using a JBL2405, but ended up with the 2404 as it's 100 degrees on the horizontal plane and matches up better with the mid horn.

I wanted a system with a little old school character in the sound - but, with some modernizations such as a time correcting digital crossover and multi-amping, with parametric eq.

Mr Peabody
08-06-2010, 03:22 PM
Sometimes we do things because we can. I have a friend who removed the crossovers from his Khorns and is now using an Accuphase active crossover to tri-amp the Khorns. He uses no less than six Jeff Rowland monoblocks. The source is an Esoteric transport and DAC with variable output so no preamp. Needless, to say the system in a home enviroment defines "loud". I wouldn't use the term "audiophile" to define the sound but the physical abuse from the SPL was unreal. I mean, the sound was very good, the Khorns in the room it was just couldn't image the way some others may have being driven by such pedigree.

Dual-500
08-06-2010, 03:30 PM
It is, but there is a lot of redundancy with their components on display. It's all about the blue lights. The front speakers were powered by their 2 kW amps which are not even in the picture. I was not particularly impressed with the overall sound. Here's another of a private system where the light show is nearly as impressive. Note the horizontal center. Do you think that breaks the 16" rule? :) This system was reputed to cost $1M.

More blue lights (http://www.hometheaterdesignmag.com/prointeriors/207mc/)

As an aside, if you Google "McIntosh rack images", you'll find a handy link. There you'll find more of the same and... pictures of other kinds of *racks*. :)

rw
Beautiful!

Dual-500
08-06-2010, 03:50 PM
Sometimes we do things because we can. I have a friend who removed the crossovers from his Khorns and is now using an Accuphase active crossover to tri-amp the Khorns. He uses no less than six Jeff Rowland monoblocks. The source is an Esoteric transport and DAC with variable output so no preamp. Needless, to say the system in a home enviroment defines "loud". I wouldn't use the term "audiophile" to define the sound but the physical abuse from the SPL was unreal. I mean, the sound was very good, the Khorns in the room it was just couldn't image the way some others may have being driven by such pedigree.
My expereince with Klipsch gear is only with a guy I know that used a pair of LaScala's in a mobile DJ setup back in the 80's. The horns were a little harsh and the mid bass was somewhat boomy.

Loud? Yes, they were loud. Similar to Cerwin Vega in terms of efficiency and output.

Not sure what your buddy is running for Klipsch in terms of the model but would guess with analog active crossover and multi amping they would get plenty loud.

Dual-500
08-06-2010, 04:10 PM
Steve you have an elaborate system. Of course, from another thread I saw you and I differ on Carver :) I wouldn't think they'd put out enough heat to worry about. Have you ever thought of going with a digital amp like Nuforce? If all four subs will be in the same room that should be something to hear. I have some Pro sound background but we used EV and Shure for the most part, filled in with some other things and sold a lot of Bogen.
I'm not familiar with Nuforce. For now, amps are good to go. For the future who knows?

A rack that size gets warm and really needs forced air flow regardless of amps used, in my opinion anyway. The back is open on that rack and it would probably run fine without any fans - certainly for background/house music that is playing now or HT.

But, it's a dual purpose setup and sometimes I like to crank up some BTO or Sammy Hagar on Saturday morning - that's when the amps start to earn a living and pumping some heat. That's what the fans are for.

EV and Shure are first class stuff. Used many Shure mics and some EV RE-20 and PL-20's as well as EV 12's in PA setups and custom bass guitar stacks. Bogen has it's place in institution sound - been around forever and can be found all over the place.

Yes, the 4 x 2245's will all be in the listening/HT room in a single enclosure. Will use JBL specs for the cabinet design with a little twist from McCauley sound.

It will be basically like a pair of McCauley CS88's side by side with the JBL tuning paramaters for the drivers. This is to save space on the frontal plane.

Sir Terrence the Terrible
08-06-2010, 04:11 PM
Well thank you for the nice critique! Laughing now my friend.

Which parts to you recommend I do away with to arrive at at nice 25% solution?

I am still checking out which pieces of your gear "I" would keep, and which "I" would do away with.


At what point did I stray from HT/music system into the realm of an absolute mess? Can you be a little more specific here "if you approach home theater like a PA system"? I'm not sure I understand what I've done with my system in terms of approach that could be considered "PA approach" and not "HIgh End HT/music" playback system approach. What am I doing in terms of system design or component selection that we wouldn't find in a real Theatre of present or past?

That was a general statement of which didn't apply to anyone in particular. I just meant the approach you have to take is vastly different between the two.


My career is currently in the mechanical engineering discipline for an aircraft manufacturing company and has been as such for a while. In the pro audio, theatre arena I'm degreed in Lighting and Sound design and have about equal working experience in reinforcement, institution sound and playback systems.

I knew you worked in sound reinforcement for sure, I understand that language very well!

Sir Terrence the Terrible
08-06-2010, 04:17 PM
It is, but there is a lot of redundancy with their components on display. It's all about the blue lights. The front speakers were powered by their 2 kW amps which are not even in the picture. I was not particularly impressed with the overall sound.

Man, what I relief. I thought I was the only one (well one out of two anyway) in the world that didn't like the sound of the Mac's big front speakers and their 2K amps.



Here's another of a private system where the light show is nearly as impressive. Note the horizontal center. Do you think that breaks the 16" rule? :) This system was reputed to cost $1M.

More blue lights (http://www.hometheaterdesignmag.com/prointeriors/207mc/)

For a million dollars, they could have done better with setting that system up. I guess some compromises had to be made, but that center channel would have been too big a compromise for me. I would say they violated the 16" rule to the hilt!!!


As an aside, if you Google "McIntosh rack images", you'll find a handy link. There you'll find more of the same and... pictures of other kinds of *racks*. :)

rw

How much of this is really for show, and how much really can be attributed to performance? That is the 1 million dollar question.

Dual-500
08-06-2010, 06:00 PM
I am still checking out which pieces of your gear "I" would keep, and which "I" would do away with.

That was a general statement of which didn't apply to anyone in particular. I just meant the approach you have to take is vastly different between the two.

I knew you worked in sound reinforcement for sure, I understand that language very well!
Reinforcement yes indeed. However, I responded "equal working experience in reinforcement, institution sound and playback systems". Covers a bit more than pure reinforcement. And a little Lighting Design and contracting along the way.

"That was a general statement of which didn't apply to anyone in particular. I just meant the approach you have to take is vastly different between the two."

On this one my bullsh!t alarm is sounding for some reason - passive agressive comes to mind.......

"I am still checking out which pieces of your gear "I" would keep, and which "I" would do away with."

Make sure it's a viable 25% solution and sounds good with classic rock - BTO, Sammy Hagar, Aerosmith, Van Halen, Eagles, Joe Walsh, T-Rex......... I do enjoy my 110db saturday morning indoor mini concerts.

Dual-500
08-06-2010, 06:05 PM
:o

Oh, I get it now, two centers isn't enough, he needs four, in a diamond shape around his TV, one on top, one underneath, and one on each side! diamond......
For TT I'd recommend a "Five (5) Center" setup - four in the conventional "Diamond" configuration and the fifth (5th) in a classic pre lubed "Suppository" type design.

Sir Terrence the Terrible
08-06-2010, 06:19 PM
Reinforcement yes indeed. However, I responded "equal working experience in reinforcement, institution sound and playback systems". Covers a bit more than pure reinforcement. And a little Lighting Design and contracting along the way.

Then you know that each of these disciplines have a different terminology that is applied, correct?


"That was a general statement of which didn't apply to anyone in particular. I just meant the approach you have to take is vastly different between the two."

On this one my bullsh!t alarm is sounding for some reason - passive agressive comes to mind......

That wasn't a BS alarm, that was a"I am getting defensive" alarm. That you can shut off, it is not necessary at all. .


"I am still checking out which pieces of your gear "I" would keep, and which "I" would do away with."

Make sure it's a viable 25% solution and sounds good with classic rock - BTO, Sammy Hagar, Aerosmith, Van Halen, Eagles, Joe Walsh, T-Rex......... I do enjoy my 110db saturday morning indoor mini concerts.

The system you see in my signature should tell you all you need to know about high quality low distortion loud sound. Not a stranger to that at all.

Sir Terrence the Terrible
08-06-2010, 06:23 PM
For TT I'd recommend a "Five (5) Center" setup - four in the conventional "Diamond" configuration and the fifth (5th) in a classic pre lubed "Suppository" type design.

Don't bother, that would not be a viable solution for me. What was that comment you said about being respectful? Whatever it was, this ain't it.

Respect is respect. Differences can be tactfully stated or just blasted out as blatent crude insults.

Now which of these two statements do you think you followed? I would say the former, so are you going to be reality, or rhetoric?

I didn't go to school and get my HT certifications just so I can go and make things up as I go along. For everything there is a reason, and there is a lot of science in this hobby. So while I may need a suppository, you perhaps could use a plug.

What a poor way to start things off..........

Dual-500
08-06-2010, 06:30 PM
Don't bother, that would not be a viable solution for me. What was that comment you said about being respectful? Whatever it was, this ain't it.

Respect is respect. Differences can be tactfully stated or just blasted out as blatent crude insults.

Now which of these two statements do you think you followed? I would say the former, so are you going to be reality, or rhetoric?

I didn't go to school and get my HT certifications just so I can go and make things up as I go along. For everything there is a reason, and there is a lot of science in this hobby. So while I may need a suppository, you perhaps could use a plug.

What a poor way to start things off..........
A sense of humor goes miles too! This isn't a getting a little "Defensive" is it? C'mon man!!!

I have a good plug!

Mr Peabody
08-06-2010, 06:48 PM
LaScalla would be a bear to lug around to say the least. I bet the finish on the cabinet was finished. My friend is using Klipschorns, the top of the line in the Heritage series, LaScalla big brother. There are three series so far in the Heritage, the original, the 2nd series "II" which is basically the same with driver and horn upgrades from the original and currently the "III" when they went to the titanium drivers and I'm not sure if II or III added the Tractrix horn technology.

I still have a few EV cabinet designs. I'd love to have a room large enough to hold a couple of their folded horns. Couple those with some mid and high horns and you'd really have a Saturday concert. I really became a big EV fan because they sounded better than anything we carried in the home audio side.

Sir Terrence the Terrible
08-06-2010, 07:34 PM
And theatres at the moment, too.

yep!



How do you achieve a realistic image with a staggered center? Certainly, such is not tolerated at an IMAX.

I can do it because A) it is identical to the left and rights, and vertically set up just like my left and right mains, and B) because the staggered height is only 4" - well within the 16" perimeter, and C) the speaker is slightly tilted back so that the acoustical center of the speaker is aimed directly at my ears, just like all of my other speakers are. That's how. You can pan an effect across the front sound stage, and there is no hint of jumping or discontinuity, just a smooth pan across the front of the room with zero timbre mismatching.



Such are value judgements not shared by everyone. Clearly when it comes to speakers, there is hardly one size that fits all. :)

rw

Well, we weren't just talking about speakers, but speaker positioning. That being said, there are not a whole lot of value judgments to be made there. It is either correctly set up, or not.

E-Stat
08-06-2010, 08:38 PM
Needless, to say the system in a home enviroment defines "loud". I wouldn't use the term "audiophile" to define the sound but the physical abuse from the SPL was unreal.
HUH? I CAN'T HEAR YOU! WHAT DID YOU SAY? :)

rw

E-Stat
08-06-2010, 08:39 PM
Which parts do you recommend I do away with to arrive at at nice 25% solution?
Maybe it's the 1U lamp panels. :)

rw

Dual-500
08-06-2010, 08:59 PM
Maybe it's the 1U lamp panels. :)

rw
Probably! Definitely don't need lights on an anp rack. Maybe a couple of the fans too. And that NASTY APC 2200XL UPS just has to go! Probably could just junk the whole rack now that I think about it..... set her up on milk crates. JK of course. Better watch it - I have STtT interacting with me on the Rear/Side eq thread.

The lights on the front, I run six in pairs and also have lights on the back of the rack. There I used a couple of small 110v clamp on with 25w lamps in them.

Worked in dim lighted rooms over racks and consoles too long. So, on this setup, when I want to adjust something, just turn on the work lights and tweak to my hearts content.

The front panel lights are Littlelights and are powered by the same 12v dc power supply as the cooling fans. At a friends advice, I put a diode in series with the lights to drop the voltage a tad - because they are running on a 12v DC supply and are designed for 12v RMS AC. Great solution - and they don't run so hot they burn you when brushing against them. Plus the lamp life is good. 5 years service and no failures or replacements.

I have a pair of LED cluster type from a Singer sewing machine I picked up on eBay. They also run on 12v. Real nice, and on goosenecks with shrouds on them. Will use on the next rack when I build it up.

E-Stat
08-07-2010, 06:16 AM
Man, what I relief. I thought I was the only one (well one out of two anyway) in the world that didn't like the sound of the Mac's big front speakers and their 2K amps.
They were most certainly powerful and had seemingly infinite reserves of power. Just unable to throw a palpable and holographic image in the room. Their 300 watt tube amps, however, sound pretty good according to a trusted reviewer friend. Forget the speakers.


I would say they violated the 16" rule to the hilt!!!
:)


How much of this is really for show, and how much really can be attributed to performance? That is the 1 million dollar question.
You got me!

rw