False wall and audio sound

[Sir Terrence the Terrible]

Boy, does it take 49 responses and twenty million quotes and unquotes to answer a simple question as "how does a false wall would effect the audio sound"?

My point exactly!

[This Guy]

i dont understand how some of you people get so upset at one another on an internet forum. You dont know the person and never will, so there's no need to argue. Just save some time and answer the guys question and end it.

[Resident Loser]

Boy, does it take 49 responses and twenty million quotes and unquotes to answer a simple question as "how does a false wall would effect the audio sound"?

...we are well beyond "answering a question"...It's like this...good ol' Terrence the Interminable tells the poster, "...sure, punch a couple of holes in the wall, pop in the speakers, and you're good to go...".

I disagree, and stated my position as to why. TtT simply has a problem with that...how dare anyone question his "expurtise"...I purport to be no "exspurt" and my experience(regardless of TtTs opinion) tells me the project isn't a simple one with simple solutions...in fact it could prove to be more trouble than it's worth...simply providing an alternate POV...

jimHJJ(...quite simple really...)

[gonefishin]

*bump*

[Sir Terrence the Terrible]

...we are well beyond "answering a question"...It's like this...good ol' Terrence the Interminable tells the poster, "...sure, punch a couple of holes in the wall, pop in the speakers, and you're good to go...".

And this was all I said? Bull old dude This is what I said

If you are speaking of a baffle wall, that will increase bass tremedously, and get rid of some modes and nodes in the room.(that would be standing waves) THX actually recommends this for THX certified rooms. I would not recommend boxing the speakers, that would create resonances that are undesireable. If you build a wall with speaker cutouts for the left, center, and right speakers with acoustical foam surrounding the speakers, you will get pretty good sound.

and this

Installing baffle walls is a common practice in THX certified rooms. I have done at least three installations using baffle walls that I can remember(I am sure there is more), and none of the problems that the individual above me listed ever showed up. While it must be carefully designed, it is doable

Did you forget the increase bass tremedously part? Or how about the carefully designed part? I mentioned the only acoustical issue you get from this mounting, and gave him a simple guidline to work with in terms of mounting. What he didn't ask for was specific construction answers, acoustical issues unrelated to this kind of install, no mention of the need for toe in, and all the other crap you brought to the table. Half the crap you mentioned there wasn't enough information to even address.

I disagree, and stated my position as to why. TtT simply has a problem with that...how dare anyone question his "expurtise"...I purport to be no "exspurt" and my experience(regardless of TtTs opinion) tells me the project isn't a simple one with simple solutions...in fact it could prove to be more trouble than it's worth...simply providing an alternate POV...

jimHJJ(...quite simple really...)

Your position was a position of complete ignorance of this kind of installation. The kinds of acoustical issues you brought up are not issues for this kind of install. If you have ANY experience doing this kind of install, the kinds of issues you raise would be in line with this kind of setup. The rather silly thing that makes me laugh is that you are arguing against something that has been done over and over again. You need to check out more magazines that feature custom installed hometheaters. Several things that you seem to forget constantly is;

He never asked any constructions questions.
He never stated a room size
He never stated a screen size
He didn't say HE would build it
He never mentioned a budget
He never said he was married or had children, a dog, or a horse.
He never asked was the easy or hard to do.

In spite of this, you still brought some of these up with absolutely no information. You call that a POV, or just fishing for a problem in a situation you don't understand. You know, just throw crap out there and see what sticks. Now had you have asked about vibration control, differences between flush mount in a cutout hole and mounting the speakers to the frame, these are issue related to this kind of setup. Not standing waves, not the lack of rearward waves effect the speakers sound, not creating more acoustical problems(because it doesn't) or any of the other non flush/baffle mounted issues you raised. Those issues you raised are problems with in room speakers, not baffle/flush mounting. You may call it a POV, I call it complete ignorance.

It is completely disingenuous of you to come here and represent yourself as the saviour of HVAIC from misinformation. Your created more misinformation and dispelled nothing. You didn't even address my responses to your so called POV

[Resident Loser]

...what you really said was:

If you are speaking of a baffle wall, that will increase bass tremedously, and get rid of some modes and nodes in the room. THX actually recommends this for THX certified rooms. I would not recommend boxing the speakers, that would create resonances that are undesireable. If you build a wall with speaker cutouts for the left, center, and right speakers with acoustical foam surrounding the speakers, you will get pretty good sound.

...and you pretty much would have left it that way if I hadn't put that bug up your @$$...perhaps if you had the forethought to include...

While it must be carefully designed, it is doable

in your initial response, I might have been inclined to let you slide...probably not, but maybe...and anyway, how do you know he wasn't ready to whip out the ol' Sawzall and start on this project simply because you intimated it was a piece of cake and would probably cure cancer and solve world hunger to boot?

Do make a note for future reference YOUR use of the word "if"...conjecture on your part is OK, however if I choose to raise some doubt it is verboten, eh?

I included everything I did simply to counter your overly simplistic answer, sorry you no likey!

And again, for the gazillionth time...

The rather silly thing that makes me laugh is that you are arguing against something that has been done over and over again.

When what I actually said was:

Once again, you can put your enclosures or drivers in any configuration you chose, but they need to be either designed for the purpose or mechanically/electronically manipulated to compensate for their environment.

Given the choice(and since they make 'em for multiple environments) why would one want to use a speaker optimized for free-field use, when a flusnh-mount or cabinet-mount model is available?...as in the case of PSB. It'll only require that much more tweaking...

Why use the Genelecs which are near field radiators and which should be toed-in, as per spec, completely out of context?

Why put your boots in the oven and expect them to be seen as biscuits?

The answer is simple...HT is simply a medium for laser-totin' mechanical lizards...accuracy simply isn't of paramount concern...it's all nothing but one-upsmanship and old fashioned popcorn makers...and ooh's and aah's...

You didn't even address my responses to your so called POV

There are around 55 posts, roughly half of which are mine...if you don't have all the answers you need, the problem isn't mine...

jimHJJ(...and it really p!$$es you off...)

[Sir Terrence the Terrible]

...what you really said was:



...and you pretty much would have left it that way if I hadn't put that bug up your @$$...perhaps if you had the forethought to include... in your initial response, I might have been inclined to let you slide...probably not, but maybe...and anyway, how do you know he wasn't ready to whip out the ol' Sawzall and start on this project simply because you intimated it was a piece of cake and would probably cure cancer and solve world hunger to boot?

Listen, this is not about you no matter how much you attempt to make it. It is about the posters question, something you failed to answer even after 27 or so responses. Your responses didn't even respond to the basic question that was asked {b}would the false wall effect anything else?[/b]. Your responses brought up issues related speakers out in the room, not flush/baffle mounted. Because of this, it was of no help at all. Of course, this wasn't about the question the poster asked was it?

Do make a note for future reference YOUR use of the word "if"...conjecture on your part is OK, however if I choose to raise some doubt it is verboten, eh?

Do make note of the mistletoe located conviently on my coattails. In the future when raise some doubt, make sure its appropriate to the design that discussed. You were totally off the mark on this one.

I included everything I did simply to counter your overly simplistic answer, sorry you no likey!

The question was simple, the answer was simple. Only an idiot thinks he needs to rewrite the constitution just to answer the question. You included everything you did, because you are not familar with this particular kind of installation. So what you did was throw everything including the kitchen sink,to hide your ignorance(which it did not) and make a feeble attempt to counter my response. Not very effective, and not particularly helpful to the original poster. You are welcomed to challenge anything I say at any time.

And again, for the gazillionth time...



When what I actually said was:

You should have stop right there. The rest of your responses were not helpful,.

Given the choice(and since they make 'em for multiple environments) why would one want to use a speaker optimized for free-field use, when a flusnh-mount or cabinet-mount model is available?...as in the case of PSB. It'll only require that much more tweaking...

How do you know it requires more tweaking, have you tried it? Do you actually have any hands on experience, or are you just guessing? You use the Genelecs because they work, and they are better than what is being marketed as in wall or flush mounted. PSB are optimized in a reflection free anechoic chamber, not a room, not in your room, and not in the posters room. PSB does not have any idea where their speaker is going to be installed.

Why use the Genelecs which are near field radiators and which should be toed-in, as per spec, completely out of context?

They require toe in when the installation requires it. They do not ALWAYS require toe in. Your still thinking inside the box. We use them because they work exceptionally well in this kind of design. Toe in is a recommendation, not a specification must.

Why put your boots in the oven and expect them to be seen as biscuits?

I guess for the same reason why you think a standing wave is a room resonance.

The answer is simple...HT is simply a medium for laser-totin' mechanical lizards...accuracy simply isn't of paramount concern...it's all nothing but one-upsmanship and old fashioned popcorn makers...and ooh's and aah's...

All of this is based on your personal experience? Or are you just complaining that the industry has grown past your knowledge. Have you ever heard any custom installed theaters. Is your opinion educated, or just some more ranting and raving because you just don't get it?

There are around 55 posts, roughly half of which are mine...if you don't have all the answers you need, the problem isn't mine...

jimHJJ(...and it really p!$$es you off...)

You call those answers? It was more like crap on the wall that is not even appropriate for this kind of installation. You don't know what pisses me off. I certainly am not bothered by the musing of an old man well past his time, with no current information on current audio technology. Remeber the question waswould the false wall effect anything else?
. You offered nothing to answer that question nor to this discussion

[Resident Loser]

...I provided ALL the info I that did (kitchen sink included) to counter your overly-simplistic response. PERIOD, end of story...sorry you no likey.

My take(and consequently MY response) on the "false wall" was as I outlined in text AND as I presented in those .jpegs. PERIOD, end of THAT story...

I guess for the same reason why you think a standing wave is a room resonance.

You mean it's not?!?!? Funny thing, these folks seem to think so:

http://www.indiana.edu/%7Eemusic/ete...standing.shtml

http://hyperphysics.phy-astr.gsu.edu...es/standw.html

I'll guess you have some new and revolutionary take on what currently comprises a standing wave in the scientific community...Oh, do 'splain Lucy...

For example you have a room whose dimensions are AxBxC...you have a loudspeaker whose low-end FR is limited so that the interaction, in that room, insofar as standing waves is concerned, is nil or negligible. Given the fact that as we move up in frequncies the wavelengths become shorter...so if we shorten a room dimension so that now it will line up with the wavelength of a lo-end freq the loudspeaker is more capable of producing, something is probably going to happen...nodes or anti-nodes...but something. Caveat emptor...

jimHJJ(...or as in your case "cabeza empty"...)

[Sir Terrence the Terrible]

...I provided ALL the info I that did (kitchen sink included) to counter your overly-simplistic response. PERIOD, end of story...sorry you no likey.

Not end of story, you provided that information because you didn't know what you are talking about. Its funny, you still don't. Simple question requires simple answer. Get that simpleton?

My take(and consequently MY response) on the "false wall" was as I outlined in text AND as I presented in those .jpegs. PERIOD, end of THAT story...

Unfortunately it didn't even come close to describing what the poster wanted.. Sorry YOU is wrongy. Speakers boxed in a free standing solid wall, get the concept? You wanna try again, and please put the speaker IN THE WALL.

You mean it's not?!?!? Funny thing, these folks seem to think so:

http://www.indiana.edu/%7Eemusic/ete...standing.shtml

http://hyperphysics.phy-astr.gsu.edu...es/standw.html

I'll guess you have some new and revolutionary take on what currently comprises a standing wave in the scientific community...Oh, do 'splain Lucy...

You still do not get it.

These standing wave modes arise from the combination of reflection and interference such that the reflected waves interfere constructively with the incident waves. An important part of the condition for this constructive interference for stretched strings is the fact that the waves change phase upon reflection from a fixed end. Under these conditions, the medium appears to vibrate in segments or regions and the fact that these vibrations are made up of traveling waves is not apparent - hence the term "standing wave".

In the case of a loudspeaker in a baffle there is no rear wave colliding with incidental waves in opposite directions coming at the listening position. There is a single incidental wave coming from the front baffle(which the ears hears first), and reflections from the back wall arriving MUCH later(which the ear interprets as another event). In the case of a speaker out in the room(can anyone say proud to the wall) you have the front wave arriving first, and close arriving second waves reflected off the front and side walls near the speaker arriving next. These waves are 180 degrees out of phase with each other. Notice in the text where is says An important part of the condition for this constructive interference for stretched strings is the fact that the waves change phase upon reflection from a fixed end.. In order for a standing wave to be audible there must be a flip in phase. This can only happen if the speakers sits IN FRONT of the wall, and you hear a combination of the direct, and later arriving reflected signals. That is what creates standing waves. If there is no combining of incident, and later arriving reflections, then there cannot be a audible standing wave. Installing a speaker in a baffle wall supresses any late arriving reflections that would be out of phase, so only the incident wave is heard. Hence, no exciting of standing waves. Since the speaker is closer to the baffle wall, it places the speaker in a high pressure zone which accounts for the boosting of the bass. Much like what you get when you push a sub against a single wall. Room resonances can occur at all frequencies, standing waves are a low frequency occurence period. Not the same thing Methuselah

For example you have a room whose dimensions are AxBxC...you have a loudspeaker whose low-end FR is limited so that the interaction, in that room, insofar as standing waves is concerned, is nil or negligible. Given the fact that as we move up in frequncies the wavelengths become shorter...so if we shorten a room dimension so that now it will line up with the wavelength of a lo-end freq the loudspeaker is more capable of producing, something is probably going to happen...nodes or anti-nodes...but something. Caveat emptor...

First, and once again, you are mixing up room deminisional resonances and standing waves. Room deminsional resonances are resonances based on room deminsions. A room that is 14ft long will have a room resonance of 40hz. This resonance is not out of phase, but in phase when arriving at the ears Standing waves are a different animal altogether. They come from the interaction of a series of reflections combining with a incident wave and flipped out of phase and only occur in a speakers omnidirectional radiation pattern which are in a speakers low bass frequencies(which excludes baffle/flush mounted designs). Two different animals that when combined together(can anyone say proud to the wall) makes things alot worse than if you have a single incedental wave with a boost in bass of about 3db.

Did the poster mention that he wanted to shorten the room deminisions? No! A free standing baffle wall does not shorten a room's deminisions. It cannot since it is not attached in anyway to the orginal rooms walls. Hence FREE STANDING. You have not change the fundemental deminsion of the room, there is just a barrier there. This would break up any side to side room modes, especially a wall 2-3ft thick.

The reality is without room deminsions from the poster, your weak attempt at saving your face is useless.

jimHJJ(...or as in your case "cabeza empty"...)

In your case "don't know ya stuff". Surf the internet, find a link, and thinks ya got it. NOT!!!

[hermanv]

At least we taught that HAVIC guy never to show his face around here again!

[Resident Loser]

...you wouldn't get it if it were on your kitchen table in a big, brown bag marked "IT"...

For all the kiddies in the peanut gallery, let's start with a few definitions and/or references:

http://www.atis.org/tg2k/_standing_wave.html

"Standing wave: In a transmission line, a wave in which the distribution of current, voltage, or field strength is formed by the superposition of two waves propagating in opposite directions, and which wave is characterized by a series of nodes (maxima) and anti-nodes (minima) at fixed points along the transmission line. Note: A standing wave may be formed when a wave is transmitted into one end of a transmission line and is reflected from the other end by an impedance mismatch, i.e., discontinuity, such as an open or a short. Synonym stationary wave."

In this instance, even though the energy we are transmitting is an acoustic wave and our "impedance mismatch" is a wall, this definition is still applicable.

And then from:

http://www.crutchfieldadvisor.com/IS...cs.html?page=2

...in a nutshell:

"Standing waves and room resonance modes

Any time you have a pair of parallel reflective surfaces (like room walls, or the floor and ceiling), you're going to experience some degree of a phenomenon known as standing waves. Standing waves distort the bass and lower midrange frequencies from 300 Hz on down... Standing waves are created when sound is reflected back and forth between any two parallel surfaces in your room. They affect frequencies below 300 Hz...A room's primary or "axial" resonance modes are based on the room's three main axes: length, width, and height. These resonance modes create bass peaks and dips of up to 10 dB throughout the room!"



http://www.audiovideo101.com/diction...nding-wave.asp

"Standing Wave
Low frequency anomaly or distortion created when a certain frequency is reproduced whose size has some special relation to the room or object it is produced in (wavelength the same size as the room dimensions) resulting in the room or object resonating with the sound and increasing the strength of the sound (the sound wave does not diminish and may instead increase as it interacts with its surroundings). The end result of a standing wave is a very loud signal greater than that presented by the original signal. The sound wave is essentially amplified by the space in which it exists."


http://www.axiomaudio.com/archives/b...e_theater.html

...Pariticularly the following:

"Choose the Correct Room Shape

If possible, avoid square rooms, because deep bass sound waves really misbehave in square rooms. They produce “standing waves,” which result in areas of extreme bass emphasis and no audible bass. Trying to fix the standing-wave problem after the fact is virtually impossible. Instead, select a rectangular shaped room with the dimensions (length, width and height) not evenly divisible by a common denominator. For example, don't choose a room 24 x 16 x 8 ft.; instead lay out dimensions of 23 x 13 x 7 feet. That way, you'll minimize standing waves."

There are more. They basically say the same thing...anyone interested can Google "audio standing waves" or "definition of standing waves"...don't take my word for it, check and see...We are not afraid! At least I'Mnot.

Anywho, back at the ranch...

In the case of a loudspeaker in a baffle there is no rear wave colliding with incidental waves in opposite directions coming at the listening position...

etc.

We aren't talking about "rear waves"...can you say red herring?...All loudspeakers attempt to eliminate (as in infinite baffle, acoustic suspension) or use/control (as in transmission line, bass reflex, ported)those...standing waves are a product of frequency vs. room dimensions REGARDLESS OF SPEAKER TYPE...free-field...in wall...in ceiling...in your shorts...If the conditions are right, standing waves ARE a reality as long as there are two(or more) parallel reflecting surfaces...sooo, bada-bing, bada-boom, bada-bite-me...

Did the poster mention that he wanted to shorten the room deminisions? No! A free standing baffle wall does not shorten a room's deminisions. It cannot since it is not attached in anyway to the orginal rooms walls. Hence FREE STANDING. You have not change the fundemental deminsion of the room, there is just a barrier there. This would break up any side to side room modes, especially a wall 2-3ft thick.

According to your initial "IF"y response, that's what you responded with...simply build a "baffle wall" and hide your PSBs...If that doesn't change a dimension or two I can't think of what would...'twern't 'til I voiced my objections that we got any sort of clariciation (as vague as it was) on the matter...cheez-and-crackers, do you actually think the folks who may have been following this object lesson in futility are as dumb as you are? Let's simplify matters...

Post #1. Pooor HAVIC asks a question...

Post #2. TtT provides the infamous and simplistic "stickin' 'em in a wall is bettr'n canned beer" response...

Post #3. RL says no, no ,no...not so simple...because...

TtT scrambles for the smoke and mirrors...

jimHJJ(..."save face"?...)

[GMichael]

You guys are so great. I would be bored as h.ll if it weren't for this thread.

[Resident Loser]

...from the Yogi Berra school of thought...

Room deminsional resonances are resonances based on room deminsions.

...and you can observe a lot by just watching...

BTW, all that text you posted with the reflected and incidental waves wasn't an ad for Bose speakers...it was an explanation of standing waves with regard to strings and air columns...destructive and non-destructive interference are simply points where sound is either augmented or cancelled(e.g. in-phase or out-of-phase) on a vibrating string or column of air...IT HAS NOTHING TO DO WITH early or late reflections from a loudspeaker. Nice basket of apples and oranges you got there fella...do try to read(and understand) ALL the links within the links provided, it tends to make more sense that way...

In order for a standing wave to be audible there must be a flip in phase

B..b...b....but if there is a flip in phase, and it's a stationary wave...th..th...th....then it's out-of-phase and nothing is audible...QUICK!...somebody get MIT on the line the laws of physics are NOT immutable???? RUN FOR YOUR LIVES...THE SKY IS FALLING!!!!

No, no...sorry it's just TtT mis-reading and mis-applying those dang diagrams again...

This can only happen if the speakers sits IN FRONT of the wall, and you hear a combination of the direct, and later arriving reflected signals. That is what creates standing waves.

No, not really...THAT'S called "Stereo Everywhere" and I think Bose may have the copyright on that...Actually, it's the passengers on the ship leaving the dock that are responsible for standing waves...

jimHJJ(...and pal (generic) yo' ship done sailed...)

[Sir Terrence the Terrible]

Room resonances are not created randomly. They have to be stimulated by a sources located near the rooms boundary's. A speaker on a stand in the middle of the room will not excite or drive any of the a rooms modes. A speaker on a stand against the front wall will excite a room resonances associated with the length of the room(front to back), but is not likely to excite any room modes associated with floor to ceiling, or side to side boundaries as it is not efficiently coupling with these boundaries. A speaker against the front wall and on the floor will couple efficiently with both the floor to ceiling and front to rear axial modes. A speaker on the floor and in a corner will excite ALL room modes efficently and cause AUDIBLE standing waves to be heard if you are situated near the room boundaries. Certain condition must be met to make standing waves audible. Your sources must be near room boundaries, and so do your ears. Once you decouple either from the boundaries of the room, room modes and nodes are not efficiently driven, and become less audible.

The reason standing waves are a problem at frequencies below 300hz is because this is the frequency that speakers begin to couple with the room boundaries more efficiently. As the dispersion pattern of the speaker becomes more omnidirectional, the better chance the speaker has of efficiently coupling with the boundaries of the room and stimulating a room modes. A speaker that never becomes omnidirectional will not efficiently couple with the room boundaries.

How does this relate to what the poster ask? The poster wants to erect a stand alone wall(that is decoupled from every room boundary except the floor) and flush mount his speakers in that wall. RL says this will create more acoustical problem and will likely stimulate standing waves in the room. He suggest that it might be better just to install them "proud" with the wall as if that will make acoustical problems go away. Wrong, it will make them worse. The poster has a sub, and it is likely it will produce all of the deep bass from the system. Since the poster has a Yamaha receiver it is likely the crossover point to the sub is 90hz. The posters main speakers are tall and narrow baffled tower, that are pretty deep in depth. The drivers are 6.5" woofers. If placed in front of the wall as RL suggests, it is likely at sometime before 90hz that this speakers output will become omnidirectional, and bass frequencies would begin to wrap around the cabinet and engage the rooms front wall. This will excite the room front to back axial mode. The fact that the speaker sits on the ground already will excite the rooms floor to ceiling axial mode. There will also be early and late arriving reflections that smear imaging, and changes the frequency response of the speaker at the ears. Hardly less problems

The poster did not say how wide this stand alone wall would be, but he did suggest up to 3ft deep. The wavelengths of the bass would have to be pretty long(deep bass)to wrap around this baffle wall, and engage the rooms front to back axial modes. They would have to be VERY long to engage any of the rooms natural boundaries. Since the poster has a subwoofer, it is not likely his main speakers that are in the wall would produce any bass with wavelengths long enough to engage any room mode. The speaker never radiates in a omnidirection pattern, not at any frequency it will likely be producing. That means no early and late arriving reflections, and no stimulating of the room axial modes and nodes. The baffle wall will create a boost in the mid bass, and the speaker is on the floor which will excite the rooms floor to ceiling mode. Both of these CAN be eq'd(especially the baffle wall boost since it is in phase with the direct output of the speaker itself). What RL proposes would require more acoustical foam and eq than baffle/flush mounting. The monolith wall is not near any boudaries, so it would be pretty hard to stimulate or drive any of the rooms modes.

RL, you just cannot mention standing waves as a stand alone issue. Standing waves and room modes have to be stimulated by the source. The closer to the room boundaries you locate the source(and your ears) the more profound standing waves become. If you limit the dispersion pattern of the speakers at bass frequencies(a baffle/flush mounting will do just that) then you decrease the chances of the speaker to interact with the rooms boundaries. Thus you do not stimulate or drive the rooms modes.

Your contention that baffle/flush mounting would be worse is not true at all. What you suggested would require twice the work to get right, not to mention more acoustical control. Your suggestion has more chance of exciting room modes than mine.

[Resident Loser]

...I propose I attempted to add information to help guide the poster in making a decision...

I propose the initial question was vague enough for me to propose two specific scenarios which I REJECTED for various reasons...

I propose that regardless of your protestations, I stand by my response to HAVIC...

I propose we are well past "helping" the initial poster and have been for some time...

I propose any relevance to HAVICs inquiry ceased somewhere around post #4...no, make that precisely at post #4...in fact the response in post #2 is highly questionable...

I propose you wouldn't know a standing wave from a standing rib roast...some "exspurt"...

I propose your "expurtise" is limited to reading trade mags that have been left around by legit acousticians/installers...

ERGO:

I propose that, you sir, are an idiot...an immature, emotional, ego-centric, know-it-all idiot to boot...

jimHJJ(..and I am done with you...sorry ericl, there goes your "hit" count...)

[Florian]

Will you two please shut up?
LOL, i am just kidding. Its fun to see other people fight like i sometimes do.

Cheers

Flo

[Resident Loser]

...of audio wisdom,contained here:

http://forums.audioreview.com/showth...?postid=110152

Well i woudnt call them fullrange just wired in series i thinkand they are horribly inefficent

...you might wanna' think twice before getting "too" involved...

Series? Parallel? This affects bandwidth how? I'd have to refer to the schematic, but I'm fairly certain they're actually both...given the nine drivers involved, such internal wiring is required to present a nominal 8 Ohm load to the driving amp...and as stated in my response, in the thread from whence your quote originates, Series one and two were of an inefficient acoustic suspension design requiring 100Wpc to get going...the latter(and current models) are ported and require around 10Wpc; far more efficient.

Besides there is no fight...I tend to refrain from a battle of wits with an unarmed person...

jimHJJ(...and, as stated in my previous response, I'm done...)

[Sir Terrence the Terrible]

...I propose I attempted to add information to help guide the poster in making a decision...

Unfortunately your so called information is not applicable to what the poster is asking. Can't get standing waves, Room modes, or dog crap unless the conditions exist for their stimulation. Had you have given the posters question some real thought, you would have plainly seen that what he proposes is doable if he planned carefully.

I propose the initial question was vague enough for me to propose two specific scenarios which I REJECTED for various reasons...

Yes, you were so busy analyzing the posters mental state, that you didn't understand(and still don't) or could invision what he was asking.

I propose that regardless of your protestations, I stand by my response to HAVIC..

Who cares? I don't. You could stand in the middle of Broadway or 5th avenue during rush hour, I don't really care.

I propose we are well past "helping" the initial poster and have been for some time...

Duh!. How many brain cells died so you could arrive at this conclusion?

I propose any relevance to HAVICs inquiry ceased somewhere around post #4...no, make that precisely at post #4...in fact the response in post #2 is highly questionable...

You have yet to disprove it. You have posted nothing here that disproves what I have stated. You had plenty of opportunities, but you couldn't deliver.

I propose you wouldn't know a standing wave from a standing rib roast...some "exspurt"...

I think I describe it quite well in the post above, It shut you up. Unlike yourself I also describe the conditions that excite them. You did not, and you could not apply it to the poster inquiry You may know what a standing wave is, but the lights are out when it comes to you describing the conditions that makes them exist. That is obvious in all of your statements in this thread. So what does that make you, a smart dummy?

I propose your "expurtise" is limited to reading trade mags that have been left around by legit acousticians/installers...

I propose that I don't care what you think. Based on the information you have provided here, proposing maybe all you can do, critical thinking, problem solving and imagination are far beyond your reach.

ERGO:

I propose that, you sir, are an idiot...an immature, emotional, ego-centric, know-it-all idiot to boot...

jimHJJ(..and I am done with you...sorry ericl, there goes your "hit" count...)

This sounds like a man that has had a cork shoved in his mouth. I guess my last post muted your sorry butt to the point that all you have left is name calling. I propose that you are a cowardly debater who does not know when he is over his head.

[Resident Loser]

...I'm only starting to do what YOU have been doing all along...

I guess my last post muted your sorry butt to the point that all you have left is name calling. I propose that you are a cowardly debater who does not know when he is over his head.

I'm sure Paul Klipsch designed his Klipschorn to exite standing waves...

Go ahead, keep on going...you'll bury yourself a little deeper...

Hey kid's gather 'round this is gonna' be sooo cool!!!

jimHJJ(...make that f*ckin' idiot...)

[Sir Terrence the Terrible]

...I'm only starting to do what YOU have been doing all along...

Uh huh......The only thing you have done so far is exibit just how irrelevant you are to this discussion.

I'm sure Paul Klipsch designed his Klipschorn to exite standing waves..

The klipschorn is designed with very specific instructions. They are to be pushed into corners tightly, and placed along the long walls of a room. The cabinet design of the speaker uses the corner walls as an extension of the bass horn. Because the baffle of the speaker(and it woofer driver) is aimed at between 30-45 degrees from the side and front walls, standing waves are completely diffused(broken up) as opposed to a subwoofer or speakers with flat baffles and square cabinets which leaves the woofer in very close proximity of the walls, and produces a very strong interaction with room surfaces. The woofer of the klipschorn fires through a folded horn design, so it loads the room much differently than a standard woofer firing directly into the room. Set a regular speaker close to a corner, and the results would be the exact opposite of the Klipschorn. It wasn't designed for corner placement. Since you are in the mood for a fight, there you go.
.

Go ahead, keep on going...you'll bury yourself a little deeper...

Hey kid's gather 'round this is gonna' be sooo cool!!!

jimHJJ(...make that f*ckin' idiot...)

An old not so smart phart trying to use words like "cool" just sounds like an old phart trying to use the word cool. Its not cool at all. A person that cannot communicate without using vulgar words is a person that lacks effective communication skills.

[Resident Loser]

...but for anyone who still cares...

http://www.keithyates.com/inwall2article.htm

"Indeed, if you were to try to install into a wall a conventional speaker whose response was tuned for freestanding placement, that is, well away from walls, you would hear a noticeable reinforcement (roughly 6 decibels) in the mid- and low-bass range. But no credible manufacturer of in-wall speakers uses a 4-pi (free space) tuning for a product destined for a 2-pi (hemispherical) environment. Further, all other things being equal, an in-wall speaker enjoys a decided advantage over non-in-walls precisely because one of the biggest variables in the performance of freestanding speakers—namely, the woofer's relationship to room boundaries-is replaced by a certainty that can be factored into the speaker's response in the design stage..."

http://www.atlantictechnology.com/ma...ystem%2020.pdf

"If there are bass standing wave problems when in-wall speakers are utilized full range the only real options are to change the listening position or add a subwoofer that can be located in a “better bass place” in the room."

http://www.axiomaudio.com/archives/b...e_theater.html

"Don't Hide Floorstanding or Bookshelf Speakers Inside Custom Cabinets

Speakers already have their own enclosures (cabinets), and are carefully engineered to perform at their best in a freestanding location, unencumbered by special custom cabinets, nooks, custom shelving, or concealed in elaborately constructed cubbyholes behind special grilles. This extra cabinetry will degrade and change the neutral transparent tonal balance that Axiom speakers are noted for. At the least, deep bass performance will be uneven or boomy and hollow-sounding, and the midrange and treble tonal balance may become noticeably nasal or muddy and congested."

http://www.itea.com/newsletters/2002...pdf/Page_5.pdf

The above link contains just some interesting references re: infinite baffles and baffle walls and Bafflettes...

http://www.cinemaequipmentsales.com/athx3.html

"A. Baffle Structure

1. Construction

With each site specific baffle drawing set supplied by the THX design office, the overall dimensions, materials specification, and installation directions must be closely followed. Also please note a minimum of 4'-3 " (1.3 meters) of available room is necessary behind the screen to construct the baffle.

2. Speaker Holes

a) Placement

The placement of the speaker holes in a THX baffle structure is very specific and is determined by the image sizes. A new baffle drawing must be generated by the THX design office if the image sizes change.

b) Size

The size of the speaker holes is determined by the equipment chosen from the THX approved equipment list."

So now argue with some others with regard to some of the topics I previously mentioned...

jimHJJ(...I'm sure you can figure out the references...)

[jneutron]

The klipschorn is designed with very specific instructions. They are to be pushed into corners tightly, and placed along the long walls of a room. The cabinet design of the speaker uses the corner walls as an extension of the bass horn. Because the baffle of the speaker(and it woofer driver) is aimed at between 30-45 degrees from the side and front walls, standing waves are completely diffused(broken up) as opposed to a subwoofer or speakers with flat baffles and square cabinets which leaves the woofer in very close proximity of the walls, and produces a very strong interaction with room surfaces. The woofer of the klipschorn fires through a folded horn design, so it loads the room much differently than a standard woofer firing directly into the room. Set a regular speaker close to a corner, and the results would be the exact opposite of the Klipschorn. It wasn't designed for corner placement.

You have an interesting understanding of standing waves, room resonance characteristics, acoustic impedance matching technology, and coupling parameters between room nodes and acoustic input..where are you getting this stuff?

Do you have any links to provide us to support some of this? Like how a horn loads the room, vs how the dihedral wall loads the horn in half, quarter, or eighth space? And why a horn generated wavefront can't excite room modes? You seem to be confusing the main firing direction with the focussing capability of horns which are limited by mouth size, such as the K's vs zero length horns like direct radiators with very small mouths..at the main room mode frequencies, both horns and directs do not have sufficient dimensions to project planar wavefronts, so your explanations are rather, umm, interesting..

Cheers, John

[Resident Loser]

...for HAVIC...You have couple of roads to take...

The simplest, since you have yet to purchase a projector/screen, would be to purchase a perforated screen. If you really like your PSBs, you can position them where they will sound best and hang the screen between and forward of them...for a sort of "psuedo-wall" sense of continuity, just flank it with acoustically-transparent scrim and voila! HT that looks aesthetically pleasing...sorta' like a retro movie theatre...little muss, little fuss...and no design/construction to contend with or demolition should the whole idea not seem quite the ticket after-the-fact.

If you really long for THX-lite and the infinite baffle concept AND yet want musical accuracy in addition to the crash and boom of your laser-totin' mechanical lizards, I would opt for one of the many in-wall units(LCRs) designed and optimized for that purpose plus an easily moved sub(yes Virginia, standing waves can still be a problem) for LFEs...Do keep in mind that while in-wall units are no longer simply a baflle with raw drivers and are closed, self-contained units, the rigidity of the wall in which they are to be placed is still quite important, as is the insulation contained therein to help deaden any structure-borne rattles, grunts or groans. There is even one manufacturer who produces what they call AcoustaCell wall inserts. These units seem to be specifically for their units, but there are probably others available...here's a link:

http://www.wildwestelectronics.net/spact6syform.html

In regard to simply popping any old thing into a wall, if you take a look at some of the links I provided along this long and bumpy road of a post, yes, an infinite baflle/baffle wall/Bafflette is a requirement for THX certification of commercial venues...however it's structure is somewhat complicated and even in it's more simplified form, requires the use of MDF in lieu of wallboard and studs. In such an application the plans MUST be THX approved and conform stringently to their parameters including use of approved speakers, which tend to look like industrial vacuums painted in lampblack...which, since they are in a wall, is no biggie. There also seems to be very specific room size/screen size/speaker placement guidelines to afford the best(as per THX requirements) performance.

jimHJJ(...round and round she goes...)

[Sir Terrence the Terrible]

You have an interesting understanding of standing waves, room resonance characteristics, acoustic impedance matching technology, and coupling parameters between room nodes and acoustic input..where are you getting this stuff?

Do you have any links to provide us to support some of this? Like how a horn loads the room, vs how the dihedral wall loads the horn in half, quarter, or eighth space? And why a horn generated wavefront can't excite room modes? You seem to be confusing the main firing direction with the focussing capability of horns which are limited by mouth size, such as the K's vs zero length horns like direct radiators with very small mouths..at the main room mode frequencies, both horns and directs do not have sufficient dimensions to project planar wavefronts, so your explanations are rather, umm, interesting..

Cheers, John

John,
I am no expert on horn loaded speakers. I do own three heavily modified klipschorn speakers that I used to use in my mixing/screening room. John Allen designer of the HPS-4000 all horn commercial loudspeaker system, and expert on horn speakers gave me the explaination. Its been awhile since he explained this to me so my explaination probably is not clear. But I do remember him saying that is was both the way the angle that the klipschorn fired bass into the room, with the combination of the fact that the woofer fires into horn as opposed to the free air like typical speakers do. Now the answer probably is much more detailed than he explained(and it probably is) but that is what he gave me.

[jneutron]

John,
I am no expert on horn loaded speakers. I do own three heavily modified klipschorn speakers that I used to use in my mixing/screening room. John Allen designer of the HPS-4000 all horn commercial loudspeaker system, and expert on horn speakers gave me the explaination. Its been awhile since he explained this to me so my explaination probably is not clear. But I do remember him saying that is was both the way the angle that the klipschorn fired bass into the room, with the combination of the fact that the woofer fires into horn as opposed to the free air like typical speakers do. Now the answer probably is much more detailed than he explained(and it probably is) but that is what he gave me.

The answer is far more detailed.

The reason a horn does what it does is it couples the energy of the source to that of the room much like a transformer. A small surface vibrating at 20 hz, for example, does not couple it's energy output very well to a room. By using a horn structure, the expanding energy with the compressible media (air) is allowed to slowly convert (as it were) to the impedance of the room.

A room corner, by it's nature, will do this for any transducer that is put there, for frequencies where the walls can be (seen) by the expanding energy. The K horns use this fact to allow the corner to act as part of that waveguide/transformer. So, both horns and direct radiators/ports/T lines/whatever...will see that enhancement when they are put into the corner...the K's just require it as part of their design.

A room will have resonances at specific multiples of the base frequency, in all 3 directions. Corner placement of any transducer will still excite those modes, regardless of the cabinet type.

Putting a speaker away from the walls does not prevent excitation of room modes, unless of course, placement is at a node. There is a complex relationship between where the transducer is within the space, the coupling efficiency to the space as a result of proximity (or lack thereof) to the boundaries..very complex.

For sound frequencies where the walls are part and parcel of the horn waveguide, there can still be coupling to room modes.

Your explanation regarding horns, room resonance, and such, was a curious mix of actual fact, and stuff that... while incorrect, can be useful for guidance in setting up systems..many times, what is taught is not correct, but has a more intuitive feel to it...giving people who don't have the math or physics skills the ability to do their job well, while not burdening them with the real information..and yes, the explanation I just gave is also a simplistic one, but arguably at the level that all here can understand.

I see the two of you arguing along these lines, and am getting very bored with it..

I miss my K horns..

Cheers, John