Two Subwoofers

[Hashpot]

Im getting the Onyo HTS790B system and the subwoofer doesn't have enough 'juice' for me. What conection am I looking for to connect a 2nd woofer? And the Sub that comes with the system is not magnetically shielded so does that mean im going to have to place it the back? I dont really have any space on the sides because the TV (Hitachi 50'' 50v720)Is on the corner of the room.

[Dusty Chalk]

There's a really detailed tutorial in the last issue of Absolute Sound (the one with the two subwoofers on the cover) of how to place one's subwoofer.

[royphil345]

Actually looks like a pretty nice little system for the money...

It seems the receiver is pretty standard... Will probably have a single RCA preamp output for a subwoofer.

You could use a Y-adapter to split the signal for two subs, which can effect the sound quality some in my experience, although many people do this. Or... some subs have an output to daisy-chain an additional sub.

If you get a better sub, you may find it's not necessary to have the original hooked up at all. Might just ruin the clarity / musicality of the better sub.

A fellow Hitachi owner!!! Hitachi is OK in my book... I have an aging Hitachi 55" rear-projection. While the picture's of course not as sharp as on the newer sets... It still looks good. Maybe even more theater-like than some. Never had a lick of trouble with it... knock on wood...

What sub are you thinking about? I'd suggest taking a look at the Sony SA-WX700. It's powerful, it goes low and it's far more musical and accurate than you'd expect for the reasonable price. A definite upgrade, yet not overkill for your system. It has an output for an additional sub as well. Don't bother with the single-driver, ported Sonys that all sound a bit boomy to me...

Oh and... Since your speakers are on the smaller side... your crossover frequency to the sub will be pretty high. Higher frequencies are easier for your ears to trace where they're coming from. Your sub will sound better as close to front and center as you can get it, especially for 2-channel music. Not magnetically shielded means it may distort the picture if placed too close to the TV. You'd just have too see if you could put it where you want without causing problems. Sometimes you gotta' do what you gotta' do to fit a system into a room. The results aren't always terrible.

[Robert-The-Rambler]

1. A fellow Hitachi owner!!! Hitachi is OK in my book... I have an aging Hitachi 55" rear-projection. While the picture's of course not as sharp as on the newer sets... It still looks good. Maybe even more theater-like than some. Never had a lick of trouble with it... knock on wood...

2. What sub are you thinking about? I'd suggest taking a look at the Sony SA-WX700. It's powerful, it goes low and it's far more musical and accurate than you'd expect for the reasonable price. A definite upgrade, yet not overkill for your system. It has an output for an additional sub as well. Don't bother with the single-driver, ported Sonys that all sound a bit boomy to me...

1. I have a new 65" Widescreen CRT Rear Projection HDTV with HDMI. It looks great!!! Who cares if it is 300 lbs? Who am I to judge? <>__<>

2. I have 3 Sony SA-WX700s behind the HDTV. The bass is thunderous without being boomy and it is not sloppy. More subs working less hard just sounds better. Actually I also have 2 18" Pyle DJ Subs being driven by a Behringer EP2500 amplifier with 450 watts each in the corners of the 20' * 12' room.

[filecat13]

Regardless of the brand of your equipment, having multiple subs provides a number of benefits. In addition to the article already mentioned above, the pioneering work in this area was done by Harman International as revealed in this white paper presentation:

http://www.harman.com/wp/pdf/multsubs.pdf

I found this immensely helpful and benefitted greatly from following the overall process.

Good luck as you look for the perfect bottom end! (Keep it clean.)

[audio_dude]

2 subs will greatly reduce your "Dead spots" as well as increase the volume and quality of your bass

[twochannelsonly]

agreed, always use 2 subs whenever possible

[audio_dude]

well, one sub is fine if placed well, but for dedicated stereo... i'd say two is best.

(if not, then single one should be placed in middle)

[Dusty Chalk]

2 subs will greatly reduce your "Dead spots" as well as increase the volume and quality of your bass

...if set up properly, if not set up properly, you will have more dead spots (more like dead bands). So count me amongst the naysayers.

[Rock789]

using physics, one could argue both sides...

for simplicity, I would suggest purchasing a single better sub...
what is your price range?
check out parts express for some sub kits which are very nice...

edit: this being said, I am building 2 subs with 12s for my ht... (and have 2 10s right now)

[westcott]

Regardless of the brand of your equipment, having multiple subs provides a number of benefits. In addition to the article already mentioned above, the pioneering work in this area was done by Harman International as revealed in this white paper presentation:

http://www.harman.com/wp/pdf/multsubs.pdf

I found this immensely helpful and benefitted greatly from following the overall process.

Good luck as you look for the perfect bottom end! (Keep it clean.)

Ditto!

Make sure they are on either side of a null or centered on two opposing walls to reduce room mode interaction. As said by others and the article, it provides better coverage for multiple listeners, like those found in a home theater.

[filecat13]

Ditto!

Make sure they are on either side of a null or centered on two opposing walls to reduce room mode interaction. As said by others and the article, it provides better coverage for multiple listeners, like those found in a home theater.

I've a bit of an odd-shaped room, wider in the front than in the back. That's actually a good thing in many respects, but it does require some attention to the details when setting things up. So, I'm using three JBL HTPS400 1000W subs, one dead center on the front wall, another almost at the midpoint of the left wall, and the third about a foot back of the midpoint of the right wall.

It took a fair amount of crawling around with an SPL meter and an AE2000 to find the best placement, and then it was night and day better throughout the room. I think one more sub against the back wall would improve things a bit more, but since I don't spend any time back there, it's not a priority.

[Florian]

The best thing is Stereo subwoofers where there is a sub left channel and a sub right channel. Improves imaging, soundstage depth and precision. But i dont know if HT Receivers have dedicated left and right subwoofer channels.

[westcott]

The best thing is Stereo subwoofers where there is a sub left channel and a sub right channel. Improves imaging, soundstage depth and precision. But i dont know if HT Receivers have dedicated left and right subwoofer channels.

Even if you were able to separate the low frequency signals using left and right channels, you would not be able to hear the difference. Low frequency signals below 80Hz are omnidirectional and the human ear can not tell what direction they are coming from even if you placed one on the left or the right. The reason for two or more subs is to to provide more even coverage of the listening area and to excite fewer room modes while doing it, if properly placed.

[Florian]

Even if you were able to separate the low frequency signals using left and right channels, you would not be able to hear the difference. Low frequency signals below 80Hz are omnidirectional and the human ear can not tell what direction they are coming from even if you placed one on the left or the right. The reason for two or more subs is to to provide more even coverage of the listening area and to excite fewer room modes while doing it, if properly placed.

Hehe, if you believe in that then thats ok. You should spend some time in other forums or even better yet, try some out yourself :-) Or ask E-Stat if he would rather have one or two electrostatic stereo subwoofers :-)

[Feanor]

Even if you were able to separate the low frequency signals using left and right channels, you would not be able to hear the difference. Low frequency signals below 80Hz are omnidirectional and the human ear can not tell what direction they are coming from even if you placed one on the left or the right. The reason for two or more subs is to to provide more even coverage of the listening area and to excite fewer room modes while doing it, if properly placed.

It does depend on the recording. If the recording was made in a live accoustic environement, then the two channels can catch bass sounds content that is out of phase with each other. In this case the two subwoofer will differentiate the signals and provide a more realistic sound, (as Forian mentioned).

[E-Stat]

Hehe, if you believe in that then thats ok. You should spend some time in other forums or even better yet, try some out yourself :-) Or ask E-Stat if he would rather have one or two electrostatic stereo subwoofers :-)

Well, I think you're both right. I find precious few subs that operate exclusively below 80 hz even when the crossover is set much lower. The subs in my HT have significant output above that frequency. A single unit would collapse the soundstage. Indeed, multiples allow for optimizing the placement to minimize room nodes.

rw

[westcott]

Well, I think you're both right. I find precious few subs that operate exclusively below 80 hz even when the crossover is set much lower. The subs in my HT have significant output above that frequency. A single unit would collapse the soundstage. Indeed, multiples allow for optimizing the placement to minimize room nodes.

rw

There is always the exception, and electrostatics happen to be one of them. One, they do not have phase and time alignment issues because of the single source delivery (as a horn lover, I can appreciate that). Two, they do need help in the lower frequencies so adding woofers is not uncommon to aid the lower frequencies beyond what a subwoofer is usually called on to do for passive radiator designs. If there is phase and time alignment info above the 80Hz, most floorstanding left and right channel passive radiator speakers are more than capable of reproducing these signals in stereo, as well.

Thanks E Stat, your comments make more sense and now I understand why you would set up your system in such a manner. It must be difficult to find a subwoofer that has a flat frequency response above 70Hz. Which ones are you using?

[E-Stat]

Two, they do need help in the lower frequencies so adding woofers is not uncommon to aid the lower frequencies beyond what a subwoofer is usually called on to do for passive radiator designs. If there is phase and time alignment info above the 80Hz, most floorstanding left and right channel passive radiator speakers are more than capable of reproducing these signals in stereo, as well.

Not all electrostats need augmentation. After much experimentation with placement of speaker, listening position, and a forest of bass traps, I get +/- 1.5 db measured results from 30 hz to 200 hz with my Sound Lab U-1s. Below that, there is a small rise to 25 hz with response falling off by about 10 db at 20 hz. Nevertheless, I consider remarkably flat response to 25 hz to be completely adequate. Blending monopole subs with bipolar mains is problematic in my experience. Had I more space and a much larger budget, I would consider the companion subs to the mains called the U-1Bs. See my gallery for pics of those.

It is with my HT system using Polk RTi-35s where I use a pair of (just ok) Eosone/Polk RS-912 powered subs. I found the smoothest transition was achieved by blending the subs at a higher frequency than I would have originally thought.

rw

[westcott]

It is with my HT system using Polk RTi-35s where I use a pair of (just ok) Eosone powered subs. I found the smoothest transition was achieved by blending the subs at a higher frequency than I would have originally thought.

rw

Now I am really confused.

Those U-1's are impressive electorstatics. Everyone should be lucky enough to own them.

[E-Stat]

Now I am really confused.

All I'm suggesting is that unless you have floorstanders with genuine bass response (my Polks are neither) and use an extremely steep low pass on the sub, then you need a pair of them. According to the Klipsch site, your system should do well. The mains go low enough and the sub offers both a low cutoff (40 hz) and steep (36 / 48 db/octave) lowpass slopes. I have heard many an HT system using small satellites and a single sub where there is a giant hole in the lower midrange/upper bass and the low end is directional.

Those U-1's are impressive electorstatics. Everyone should be lucky enough to own them.

Thank you. I am extremely pleased with the SL speakers. While not for the 100 db crowd, they simply disappear. Sonically, if not visually.

rw

[westcott]

All I'm suggesting is that unless you have floorstanders with genuine bass response (my Polks are neither) and use an extremely steep low pass on the sub, then you need a pair of them. According to the Klipsch site, your system should do well. The mains go low enough and the sub offers both a low cutoff (40 hz) and steep (36 / 48 db/octave) lowpass slopes. I have heard many an HT system using small satellites and a single sub where there is a giant hole in the lower midrange/upper bass and the low end is directional.


Thank you. I am extremely pleased with the SL speakers. While not for the 100 db crowd, they simply disappear. Sonically, if not visually.

rw

E-Stat,

First, I want to say how pleased I am that you stepped in and clarified exactly what your situation is and explaining why you have taken the approach you have. Without your honesty and participation, this discussion would have been fruitless.

Second, I think I have found a new friend in the forum and have a great deal of respect for you, your diplomacy, and your knowledge.

I would never knock someone elses speakers and your forthrightness is to be applauded. I now understand what you are trying to accomplish and why and that would never of happened without your input.

I look forward to further discussions with you and, as always, hope I can learn as much as possible from you.

If you ever find yourself in the Houston area, you are welcome.

[orgasmdonor]

In my experinence....I have a 20x25 ft room in the basement. One of my SVS subs could handle it with no problem. I purchased the second and stacked them. l immediately noticed a gain in pure depth. I link that to the amount of air two quality subs can push. You also gain decibles (around 3). If you just want one sub make sure that it can MORE than adequately push enough air per your room size. You always want to make sure you have more than you need in the bass area....given all the different ways and times things were recorded.

[Dusty Chalk]

Hey, you should try this: unplug the bottom one. Adjust the volume so that the top one is pushing the same amount of air that the two together were.

My suspicion is that getting the sub up off the ground made the bigger difference than getting a second one. Getting a sub up off the ground is a known improvement.

[westcott]

Harman International's testing has shown that placing subwoofers at opposing locations gives better coverage of the room for a wider listening area, and if placed midway of each wall, excite fewer room modes.

http://www.harman.com/wp/pdf/multsubs.pdf