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ryjam282
11-22-2004, 07:09 AM
I have a HTR-5790 and it only has the one output for the sub. Now, I have a larger room and many people on here have suggested getting another sub. My question is, do I just buy a male to 2 females splitter and plug the 2 subs in that way? Will that have any problems with sound quality? If so, what do you suggest?

kexodusc
11-22-2004, 07:29 AM
Slow down, ryjam282.
Before you start getting into that, I beg you to reconsider. I had 2 subs (paradigm PW-2200 and PW-2100 connected to my RX-V1400 in "stereo" or whatever. I tried a few placements: front and back of room, sides, in stereo position near my mains. And no matter what I did, I didn't notice much improvement in bass performance other than a more power and volume. It might have made the bass more uniform throughout the room, but from the listening position, the benefit was really minor.

I've since sold one of the subs, and realized that I'll be much better off to have one high powered, good sub that will fill the room, than 2 subs that don't quite perform as well.
Without knowing what you currently have it's hard recommend something for you specifically, but say you have two respectable subs with responses as low as 25 - 28 Hz or so, and a combined RMS power of 800 watts.
IMO you are much better off to drop the response to 20-22Hz (which is much, much, deeper and lower than you'd expect from just 3 - 5Hz) and 800-1000 watts. You'll have less integration problems blending only 1 subwoofer in, and probably a tighter, better sound all around.

Something to consider.

ryjam282
11-22-2004, 07:33 AM
kexo, thanks for the response. I have to say thanks a lot for the heads up, cause I still have not purchased it. I will take your word for it and try it this way. I still have not got everything set up from when you guys last help me with the room setup. We are still trying lots of different things. I will post updates when it is completed.

kexodusc
11-22-2004, 07:46 AM
Definitely do what you can with your room before buying anything else...that's usually the cheapest fix, and is probably necessary anyway.

I'm a little divided myself on the merits of 2 subs. I think if you really, really, knew what you were doing, had the delays, phase adjustments, and positioning absolutely perfect, you could get startling results. I think Geofficin has 2 subs in his system if I recall.

Subwoofers are pretty complex to be installed PROPERLY. Alot more can go wrong adding a 2nd sub than can go right, and to get them setup right is a fair amount of headache for most people. For the same money, I would always buy 1 dynamite sub, instead of 2 decent ones.

I would advise you to look into a parametric equalizer for the sub you have too...you might find that you're hearing the loudest peak and setting the sub accordingly, hence muffling most of the bass. YPAO doesn't really do much eq'ing for subs. Woochifer could probably give you better advice in this area.

ryjam282
11-22-2004, 07:58 AM
I Wooch chimes in then. If not, I will PM him or something.

As far as the room positioning being perfect, I have come to the conclusion that it will be pretty much impossible but I am ok with it as long as it sounds good to me. I am sure I will love it. Having finally been able to use the 7.1's like there designed to be used. Do you have a link for the website that has the proper positioning for the home theater speakers? I have seen it on here before but can't seem to find it.

Again, I thank you for you expertise and I just can't wait to get this all finished so I can post how it turns out.

htfan14
11-22-2004, 08:17 AM
I'm using 2 subs in my system and loving it. One is placed in the front right corner of the room the other in the back left corner. Both are 10" Velodyne's. In my case I got a very good deal from a friend on the second sub or I would not have ever tried this. Sure glad I did, thought the U571 depth charge scenes were loud before but now all I can say is WOW!!!

kexodusc
11-22-2004, 08:38 AM
I don't have any websites for 7.1 speaker placement, you should look at the 5790's manual...when I went to 7.1, I did a bunch of google searches, and the manual from Yamaha just confirmed what they said.

A few rules of thumb...try to make an equilateral triangle between the sweetspot, and your mains speakers...the distance between your mains should be roughly the same as the distance from a the sweetspot to each speaker...then decide if you like to be nearfield, or farfield (moving closer or a bit further).
I place my side surrounds about 3 feet above my head, 3 inches behind my ears, to the sides...and the rears are about 6 ft apart on my backwall, but if my room was smaller, I'd move them in closer together...maybe 2 to 4 ft apart.

Woochifer
11-22-2004, 01:19 PM
I would suggest that you pull down some of Harman's white papers on this subject. Their research found that using two subs helps to make the bass more even overall. (the placement in their diagram had one sub along the middle front wall and another one along the middle back wall, obviously you would need considerable space behind your listening position to accommodate this setup) With one sub, you're more susceptible to room interactions that create huge peaks and/or nulls. These can be remedied with careful placement, room treatments, and parametric equalization. But, using two subs is another (and some would argue more effective) way to help alleviate some of these room induced issues.

As kex pointed out, the auto calibration function on that Yamaha receiver does not correct far enough into the bass frequencies to be effective for subwoofer integration. You might need to get an outboard parametric EQ to address any room-related problems that might crop up in the 20-60 Hz range (this is the majority of the audible range that a subwoofer is supposed to cover).

http://www.harman.com/wp/index.jsp?articleId=1003

With regard to a 7.1 speaker setup, keep in mind that if your sofa is right up against the backwall, you're probably better off sticking with a 5.1 setup. The positioning that Dolby recommends with a 5.1 setup is to raise the surrounds about 2' above ear level and point them direclty at one another in order to diffuse the sound sufficiently while retaining some degree. I also like placing the surrounds about 110 degrees off center (this is only slightly behind the listening position).

Woochifer
11-22-2004, 01:28 PM
Slow down, ryjam282.
Before you start getting into that, I beg you to reconsider. I had 2 subs (paradigm PW-2200 and PW-2100 connected to my RX-V1400 in "stereo" or whatever. I tried a few placements: front and back of room, sides, in stereo position near my mains. And no matter what I did, I didn't notice much improvement in bass performance other than a more power and volume. It might have made the bass more uniform throughout the room, but from the listening position, the benefit was really minor.

In some of the articles I've read on this subject, the uniformity of the bass is one of the more touted benefits of a two sub setup. You're right in that two subs won't do anything to increase the bass extension, but they can help to alleviate some of the room induced issues in smaller rooms. The main disadvantage of a parametric EQ is that it primarily benefits whoever sits in the listening position. Move a few feet to the right or to the left along the sofa and the bass might sound very different. Bass traps affect the entire room, as does a two-sub setup. That Harman white paper that I linked to tests the effects from multiple subwoofer setups.

I think in your case, the issue might have been using two different types of subs. If I recall, Terrence posted on this subject a while ago and indicated that to get the benefit from a two sub setup, you need two identical ones.

Geoffcin
11-22-2004, 06:20 PM
I have a HTR-5790 and it only has the one output for the sub. Now, I have a larger room and many people on here have suggested getting another sub. My question is, do I just buy a male to 2 females splitter and plug the 2 subs in that way? Will that have any problems with sound quality? If so, what do you suggest?

You will need a db meter, and a good setup DVD like the Avia. These things are a good thing to have no matter if your using one or two subs.

First you will need a splitter from your receiver, and then, if your subs have dual input like mine, another splitter for each sub so that both line level inputs on the sub have signal. With subs that have dual voicecoils, this is absolutely necessary so both coils are used.

Right now to lower the room nodes to the minimum I have one sub in the corner, and another 1/3 out from the side wall. The corner sub is set 3db less than the other, and they both together have a flatter, and deeper response than one alone. It took me and a buddy only a few hours, and a bottle of single malt to get it all worked out just right.

Richard Greene
11-23-2004, 01:51 PM
[QUOTE=Woochifer]I would suggest that you pull down some of Harman's white papers on this subject. Their research found that using two subs helps to make the bass more even overall. (the placement in their diagram had one sub along the middle front wall and another one along the middle back wall, obviously you would need considerable space behind your listening position to accommodate this setup)
RG
The Welti white paper at the link you mention is by far the worst white paper on subwoofers and room acoustics I have ever read on the internet.

Sorry you happened to be the person who posted on this white paper, as you give otherwise good advice on subwoofers.

Readers of the white paper are initially confused by the intent of the finite element computer analysis.

Next, it's pure junk science to assume a computer simulation correlates with real listening room measurements ... when you have done absolutely no room measurements to verify the model.

The intent of this simulation is to get the most consistent bass frequency response from seat to seat within a large area (including many seats) in a large home theater room.

This goal may be useful for small auditoriums or very large home theaters.

However people reading the white paper may not realize that smooth bass frequency response at their listening position is not a priority at all ... and that's exactly what most people at this forum are interested in.

In addition, Tom Nousaine has posted on a USENET group that he has measured the
mid-wall recommendation and it did not outperform one sub in a room corner.

I'll also add that satellite subwoofer integration can only deteriorate as subwoofers are moved more than a few feet away from satellite speakers.

Subwoofers placed on opposing walls do one thing to the bass frequency response -- they are placed out of polarity and therefore fail to excite odd-order standing waves between those opposing walls. Whether that results in subjectively better or worse sounding bass = flip a coin. In general you want to reduce the effects of all standing waves evenly.
If you eliminate one room mode the remaining room modes may become more audible and annoying than before.

Richard Greene
11-23-2004, 02:26 PM
[QUOTE=Woochifer]In some of the articles I've read on this subject, the uniformity of the bass is one of the more touted benefits of a two sub setup.
RG
It is easily verified by measurements that using two subwoofers on opposite sides of the room (the common left-right subwoofers) only makes one difference to bass frequency response -- the first-order axial room mode between the side walls is not excited because the subwoofers are located out of polarity for that room mode.

That can be useful for home theater because that room mode causes large variations in bass frequency response between a seat half way between the side walls and off center seats.

The third, fifth and other odd-order axial room mode between the side walls are already similarly affected by using left and right satellite speakers (these room modes are almost always above subwoofer range).


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You're right in that two subs won't do anything to increase the bass extension, but they can help to alleviate some of the room induced issues in smaller rooms.
RG
There is rarely much of a subjective benefit from using two subwoofers in small rooms other than making it simpler to integrate subwoofers and satellite speakers which is a
no-brainer with two subwoofers.

See above answer for the total effect of two subs at the common left-right positions.
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The main disadvantage of a parametric EQ is that it primarily benefits whoever sits in the listening position.
RG
Not true.
The main disadvantage is no effect on nulls .

Parametric equalization of a bass peak caused by a front to rear standing wave will equally improve the bass frequency response for all listeners whose ears are located roughly the same distance from the front wall, such as three people sitting side by side on a couch.

Equalization of a bass peak caused by a floor to ceiling standing wave will also improve the bass frequency response for all listeners whose ears are roughly the same distance from the floor (+/- 6 inches)

Equalization of a bass peak caused by a side wall to side wall standing wave may improve the bass frequency response for all listeners whose ears are the same distance from the side walls such as one listener five feet from the left side wall and another listener five feet from the right side wall -- listeners near halfway between the side walls, however, hear a significantly different bass frequency response than off center listeners so this room mode is tough to equalize for more than one seating position.
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I think in your case, the issue might have been using two different types of subs. If I recall, Terrence posted on this subject a while ago and indicated that to get the benefit from a two sub setup, you need two identical ones.
RG
It would make little difference if subwoofer A was a 12" sealed model XXX and subwoofer B was a 12" sealed model YYY as long as their frequency response was similar.

Richard Greene
11-23-2004, 02:36 PM
I have a HTR-5790 and it only has the one output for the sub. Now, I have a larger room and many people on here have suggested getting another sub. My question is, do I just buy a male to 2 females splitter and plug the 2 subs in that way? Will that have any problems with sound quality? If so, what do you suggest?
RG:
You can use a Y splitter to connect two subwoofers.

Using two subwoofers allows you to create the same bass SPL (volume) as one subwoofer but with the two woofer cones stroking a little more than half as much = lower harmonic distortion that may be audible.

Two subs are very easy to integrate with two main speakers.

Two subs can provide a more consistent bass frequency response across a listening room as left-right subs are located out of polarity and do not excite the first order axial room mode (standing wave) between the side walls (loud bass near the side walls and weak bass half way between the side walls is the symptom of that standing wave.

Two subs also cost twice as much as one sub and take up twice as much space.

There is sometimes a tradeoff of buying one good low distortion subwoofer for $X or buying two mediocre moderate distortion subwoofers for $X -- two mediocere subwoofers may or may not sound better than one good subwoofer.

Sir Terrence the Terrible
11-23-2004, 04:27 PM
I think in your case, the issue might have been using two different types of subs. If I recall, Terrence posted on this subject a while ago and indicated that to get the benefit from a two sub setup, you need two identical ones.
RG
It would make little difference if subwoofer A was a 12" sealed model XXX and subwoofer B was a 12" sealed model YYY as long as their frequency response was similar.

I think that is what I said. I believe the individual wanted to use a 8" and a 12" sub. I said it wasn't going to be particularly effective as you need two subs with IDENTICAL driver sized in order for it to work well.

Doc, its good to read your posts again. You were sorely missed while you were drunk, and in detoxification. Too much port?

Woochifer
11-23-2004, 05:16 PM
Doc -

Good to have you back, even if it means sending me back a grade or two! :)



I think in your case, the issue might have been using two different types of subs. If I recall, Terrence posted on this subject a while ago and indicated that to get the benefit from a two sub setup, you need two identical ones.
RG
It would make little difference if subwoofer A was a 12" sealed model XXX and subwoofer B was a 12" sealed model YYY as long as their frequency response was similar.

Kex was referring to a pair of subs, one of which uses a 10" driver while the other uses a 12" driver.

Richard Greene
11-23-2004, 05:23 PM
[QUOTE=Sir Terrence the Terrible]I think that is what I said. I believe the individual wanted to use a 8" and a 12" sub. I said it wasn't going to be particularly effective as you need two subs with IDENTICAL driver sized in order for it to work well.

Doc, its good to read your posts again.
You were sorely missed while you were drunk,
and in detoxification. Too much port?

RG
I'm still drunk, however during detox I did swear off mind-altering drugs such as
peanut M&M's forever.

I don't get why anyone would want to buy any single 8" woofer advertised as a "subwoofer".

Sure three long-stroke 8" drivers can make up one decent subwoofer but
for most people one 8" driver* or even one 10" are just not enough for low distortion bass
unless they are ported, the room is small and the listener doesn't care for loud bass ....
In udder woids, as dey say in Nu Yawk where I'll be tomorra night, a total looza.

I use a 15" +/- 20mm XMAX driver (Kove Z15D) for my car subwoofer and I still can't convince some people one 8" or one 10" sealed subwoofer is not enough for their living room or family room! Maybe if the room was 12' by 10' by 8' but not most rooms.

So it looks like I'm back ... still ranting and raving about bass.

R. BassNut Greene

PAT.P
11-23-2004, 10:52 PM
I don't get why anyone would want to buy any single 8" woofer advertised as a "subwoofer".

Sure three long-stroke 8" drivers can make up one decent subwoofer but
for most people one 8" driver* or even one 10" are just not enough for low distortion bass
unless they are ported, the room is small and the listener doesn't care for loud bass ....
In udder woids, as dey say in Nu Yawk where I'll be tomorra night, a total looza.

I use a 15" +/- 20mm XMAX driver (Kove Z15D) for my car subwoofer and I still can't convince some people one 8" or one 10" sealed subwoofer is not enough for their living room or family room! Maybe if the room was 12' by 10' by 8' but not most rooms.
-----------------------------------------------------------------------------------------------------------------------------------What are you talking about not considering a 8"as a subwoofer? Ever check out a Energy Encore 8" sub or Dalhquist QX100SA ? As for 10" sub Paradigm as PS 1000,Energy as the S10.2 sub (ect ect ect) I see you said you have a 15" driver for your car subwoofer (is your car bigger than a room 12x10x8) What is the size of your subwoofer at home and what is your room size?To have a 15"subwoofer in a car you probably would need a 80" + subwoofer to satisfy you.I have a 8" and 10" sub and they do kick out the bass and my room is 26 x 16.Im sure there lots of us with 8 and 10 subwoofer for sound system !Pat.P :mad:

kexodusc
11-24-2004, 06:38 AM
Yes, Mr. Richard Greene, as Wooch said, I used two nearly identical subs, one 10" and one 12"from the same product line. The 10" sub IMO actually was actually the better of the two IMO, a bit tighter, faster, more accurate or whatever.

Didn't matter what I did, the 2nd sub actually made things worse in many cases. In fact SPL was the only thing I notice that improved, but I didn't need anywhere near that level of SPL anyway. I'm not sure the distortion would be audible with one subwoofer even at loud volumes I sometimes play.

One of the most annoying and frustrating problems with my 2 sub setup was that the bass would seem to llinger in the room a fraction of a second longer than I felt it should..it sounded delayed, etc...I'm sure this had to do with reflections or something because the delay times were matched very, very closely. Unless it's possible the response time of the different woofers changes with frequency...At any rate , it didn't do much of anything for smoothing out the room response as near as I could tell with my setup discs. In fact, some peaks got further out of hand, some new ones were introduced. Eventually I took one sub downstairs to my 2nd system, and much prefered the one sub. I've since sold it.

I don't doubt that 2 subs could be better, I just feel that all the time, effort, and placement requirements (if possible in my room given my furniture, etc) were far too difficult, (qualifier: In my room) and a better sub was a more viable alternative given the costs.

In your opinion, would you be better off to buy one higher quality, better performing subwoofer and use parametric equalization, or two lower performance subwoofers, and try to acheive synergy between them? Assuming a given budget. What would you recommend to the average consumer, who may not have the level of expertise you do? Thanks.

Sir Terrence the Terrible
11-24-2004, 10:07 AM
In your opinion, would you be better off to buy one higher quality, better performing subwoofer and use parametric equalization, or two lower performance subwoofers, and try to acheive synergy between them? Assuming a given budget. What would you recommend to the average consumer, who may not have the level of expertise you do? Thanks.

Now that my boss has returned to the board, I shall assume my old position as his trusty assistant Baldy.

Because I know my boss well, he will say it is better to have one high quality sub with parametric eq, than two lower performing subs. Now if I am wrong, you are welcome to slap me on me on my hairless crown, get me down on all fours, and make me bark like a dog!

kexodusc
11-24-2004, 10:16 AM
Now if I am wrong, you are welcome to slap me on me on my hairless crown, get me down on all fours, and make me bark like a dog!

Man, I've always wanted to have someone say that to me...except I pictured it would be Catherine Zeta Jones or Halle Berry, not Sir Terrence the Terrible...er...no offense, Sir T.

Now, can anyone think of any negative effects, or drawbacks to using Parametric Eq???

lattybuck
11-29-2004, 12:37 PM
One of the best systems using subwoofer set up's I have heard myself was using 2 subs. They were split off one from the front left and one from the front right main speakers ion a 5.1 system. It was originally a single sub system a friend wanted to try adding another sub to to see the difference. He talked the audio shop into letting him try an extra sub out. We used the crossover in the subs by wiring between amp and preamp at 60hz then killed the center and rear speaker output at 60hz to match. His mains, surround and center speakers all had good response to below 60hz already. This made a "stereo" effect with the bass that just seemed to sound more natural. As opposed to the single point sub approach. I seem to always be able to identify a single sub too easilly. It does something to the overall soundstage for me. That system was basicly just an experiment for us and he kept it, utilized 2 Revel B15 subs. It was difficult to balance the subs, but we followed the recomended Revel setup for "stereo" subs plus utilizing Revels EQ computer program and some meters we borrowed. It is amazing to listen to. The soundstage, at least as I refer to it as being audibly locating insturments within the room, was definately improved over the single Revel B15. If I get the cash I will definately do the same one day myself.
I have heard numerous people tell about utilizing 2 subs and having very good sound with some difficulty in setup. But it can be worth the hassle in the long run.
Your call and hearing in the end as always.
Take care

ryjam282
11-30-2004, 08:27 AM
Thanks so much for everyone's replies. I have a friend who has an indetical set of speakers as me so I will give his sub a try with mine and see what we can figure out.

Stu-r
12-26-2004, 07:57 PM
Not only is a single subwoofer cleaner. But you might also try higher subwoofer crossover frequencies. I've found that they're not only for speakers with poor low frequency response. They also do a great job of cleaning up room effects simultaneusly excited by all of the non-sub speakers.