Multiple Subs- do they need to match?

[Johnny B. Galt]

Since my reciever will support it, I''d like to add another sub to my HT setup. My setup is all Paradigm monitor series with a single PS1200 sub. I've been quite happy with it but kind of have the "upgrade" bug.
My question is: Do both subs need to match eachother in size/power/LFE? I don't really know what to expect for a benefit from a second and I'd probably use Audessey to help adjust the levels. Paradigm no longer makes the PS1200 so I'd be looking for a used one- or can I get something else? My room isn't large (15x25 plus a 12x10 opening)

[kevlarus]

Since my reciever will support it, I''d like to add another sub to my HT setup. My setup is all Paradigm monitor series with a single PS1200 sub. I've been quite happy with it but kind of have the "upgrade" bug.
My question is: Do both subs need to match eachother in size/power/LFE? I don't really know what to expect for a benefit from a second and I'd probably use Audessey to help adjust the levels. Paradigm no longer makes the PS1200 so I'd be looking for a used one- or can I get something else? My room isn't large (15x25 plus a 12x10 opening)

Personally I would just go with a larger sub, but depending on its placement it may not be as balanced in the room as it could be (ie, one person slightly closer to it than the someone else).

I know there's been lots of discussion about matching speakers in general, but I really try to match the sub if you decide on a second just to keep your sanity in attempting to balance the sound from both subs with respect to layout and size of the room.

I know most setups say to put the sub at the front but in some situations to can put it in the back pointing towards the wall in the front where the receiver/tv is and get bounce back from the entire wall --- you'll need to adjust the phase otherwise some of the base form the front/centers will cancel each other.

[Sir Terrence the Terrible]

Since my reciever will support it, I''d like to add another sub to my HT setup. My setup is all Paradigm monitor series with a single PS1200 sub. I've been quite happy with it but kind of have the "upgrade" bug.
My question is: Do both subs need to match eachother in size/power/LFE? I don't really know what to expect for a benefit from a second and I'd probably use Audessey to help adjust the levels. Paradigm no longer makes the PS1200 so I'd be looking for a used one- or can I get something else? My room isn't large (15x25 plus a 12x10 opening)

Your room is the same size as my theater room, and I have four subs in that room. Yes, your sub should be identical. This keeps one lesser sub from dragging a more powerful sub down with distortion from being driven too hard to keep up with the better more powerful sub. It also assures one that identical frequency responses are projected into the room which makes equalization easier to do.

Two subs in the two front corners of a room smoothens the bass response over the entire first row of seats. It also gives the system greater headroom which lower distortion coming from each sub. 2 subs work less hard to achieve X SPL level than one.

I don't know if Audessey will recognize two subs in its receiver implementation, or even work on two subs. I got Audessey sub software especially because it handles 2 or more subs.

[pixelthis]

Your room is the same size as my theater room, and I have four subs in that room. Yes, your sub should be identical. This keeps one lesser sub from dragging a more powerful sub down with distortion from being driven too hard to keep up with the better more powerful sub. It also assures one that identical frequency responses are projected into the room which makes equalization easier to do.

Two subs in the two front corners of a room smoothens the bass response over the entire first row of seats. It also gives the system greater headroom which lower distortion coming from each sub. 2 subs work less hard to achieve X SPL level than one.

I don't know if Audessey will recognize two subs in its receiver implementation, or even work on two subs. I got Audessey sub software especially because it handles 2 or more subs.

No wonder you never listen to anybody.
YOU'RE DEAF.

[Sir Terrence the Terrible]

No wonder you never listen to anybody.
YOU'RE DEAF.

I don't listen to people who do not know what they are talking about(much like yourself), and I wouldn't do so even if I didn't have subs at all. Besides, you don't go deaf listening to frequencies under 80hz, it is extended exposure to high and mid frequencies that does that. Our ears are not that sensitive at 80hz and below(where my subs operate) as they are at 1-4khz. That's science, not some crap you pull from your bum.

[E-Stat]

Your room is the same size as my theater room, and I have four subs in that room. Yes, your sub should be identical. This keeps one lesser sub from dragging a more powerful sub down with distortion from being driven too hard to keep up with the better more powerful sub. It also assures one that identical frequency responses are projected into the room which makes equalization easier to do. .

Ditto. The very best systems I've heard use symmetrical sub arrangements ranging between two and twelve drivers. Duke LeJeune's SWARM subwoofer system operates on that principle as well.

rw

[pixelthis]

Since my reciever will support it, I''d like to add another sub to my HT setup. My setup is all Paradigm monitor series with a single PS1200 sub. I've been quite happy with it but kind of have the "upgrade" bug.
My question is: Do both subs need to match eachother in size/power/LFE? I don't really know what to expect for a benefit from a second and I'd probably use Audessey to help adjust the levels. Paradigm no longer makes the PS1200 so I'd be looking for a used one- or can I get something else? My room isn't large (15x25 plus a 12x10 opening)

What I like to do, when I have a spare sub is use it for the rears.
Keep your main one for the main sub out, use the bypass on the sub for the rears.

[Sir Terrence the Terrible]

What I like to do, when I have a spare sub is use it for the rears.
Keep your main one for the main sub out, use the bypass on the sub for the rears.

That will do wonders for the acoustics when both subs are playing. You ever heard of bass cancellation? Aside from that, there is not enough bass in the rears to dedicate a separate sub to, it is a waste of money, and acoustically bad for accurate playback. Ever notice what size the surround speakers are in a movie theater? They don't do bass under 80hz, and we mixers don't mix deep bass there for fear of damaging a theater's surround speakers.

[pixelthis]

That will do wonders for the acoustics when both subs are playing. You ever heard of bass cancellation? Aside from that, there is not enough bass in the rears to dedicate a separate sub to, it is a waste of money, and acoustically bad for accurate playback. Ever notice what size the surround speakers are in a movie theater? They don't do bass under 80hz, and we mixers don't mix deep bass there for fear of damaging a theater's surround speakers.

Glad you agree with me, it does do wonders.
And yeah, you get bass cancelation if you play the same material over all channels,
and don't know how to set up a speaker system.
For us peeps with brains it can work out, but is tricky so I dont do it much.

[rob_a]

It is possible to run two different sized subs, pending on how you set the crossovers and power on them, You can get a very nice sounding bottom end. I would not run different brand subs.

[Sir Terrence the Terrible]

It is possible to run two different sized subs, pending on how you set the crossovers and power on them, You can get a very nice sounding bottom end. I would not run different brand subs.

You are going to inevitibley run into one subwoofer performance peaking before other, which will cripple the entire bass region. The only thing crossover will do is control how much upper frequency information get's into the subwoofer system, it will not control how much deep bass is running into each system. You could turn the weaker one down, but then that eleminates the very reason for having two - driver coppling, and the smoothing of the frequency response over the first row.

[Sir Terrence the Terrible]

Glad you agree with me, it does do wonders.
And yeah, you get bass cancelation if you play the same material over all channels,
and don't know how to set up a speaker system.
For us peeps with brains it can work out, but is tricky so I dont do it much.

You are full of $hit Pix, just full of it. Now, tell us how you peeps with brains assemble a multiple subwoofer system that covers both the rears and the fronts and avoids bass cancellation? Can you do that? Keep in mind, the mix has already been established, and you cannot change it.

I anxiously await your answer to this.....

[rob_a]

tell us how you peeps with brains assemble a multiple subwoofer system that covers both the rears and the fronts
I anxiously await your answer to this.....

I personally would not run a sub using the rear channels, just a mix of the fronts.

[audio amateur]

You are full of $hit Pix, just full of it. Now, tell us how you peeps with brains assemble a multiple subwoofer system that covers both the rears and the fronts and avoids bass cancellation? Can you do that? Keep in mind, the mix has already been established, and you cannot change it.

I anxiously await your answer to this.....

Why do you even bother? You know he is simply provoking you..

[pixelthis]

You are full of $hit Pix, just full of it. Now, tell us how you peeps with brains assemble a multiple subwoofer system that covers both the rears and the fronts and avoids bass cancellation? Can you do that? Keep in mind, the mix has already been established, and you cannot change it.

I anxiously await your answer to this.....

I anxiously await your total breakdown when you flunk your GED.
You might get some trouble if the front channels are the same as the rears.
But they are not in a 5.1 system, so "bass cancelation " wouldnt be a serious problem.
If the rears are the same as the front signals you might get problems.
I have seen several systems, but rarely do it myself because it can be trouble, but
then again I DONT EVEN LISTEN TO A SUB on two channel, only use one for movies.

[Johnny B. Galt]

Sir Terrance-
So your preference would be for two matched subs in equal positions in front? I've only got one row of seats (aka "couch") and there is a definite "sweet spot"- so play to that? I ran multiple coax lines to different locations in the room so I could play with positions. I was originally thinking of one in front (roughly 11 oclock) and one in the back offset (5 oclock).but don't know what this would accomplish. Also, the back third of the room is tile.

[Sir Terrence the Terrible]

Sir Terrance-
So your preference would be for two matched subs in equal positions in front?

Correct!

I've only got one row of seats (aka "couch") and there is a definite "sweet spot"- so play to that?

I would, unless you plan on adding more seats later.

I ran multiple coax lines to different locations in the room so I could play with positions. I was originally thinking of one in front (roughly 11 oclock) and one in the back offset (5 oclock).but don't know what this would accomplish. Also, the back third of the room is tile.

I would not locate a sub on tile, as it would emphasize the floor to ceiling resonance by boosting it with a strong first reflection. Having two mono sources widely spaced apart reproducing the same signal is an open invitation to multiple cancellation nodes Both subs will have very different frequency responses, and it is likely you will not really gain much boost in output with them being spaced so far apart. Also, neither sub will have much LF support when placed that close to the center of the room. I would only locate my sub in the 11 oclock position if my room was square, had a VERY powerful sub, and good EQ to create a house curve to support the lack of LF support.

[Tarheel_]

Sir TT,

I have a Def Tech 15" sub...it's nice, but older model. In your opinion, would I be better off buying another identical Def Tech sub or selling mine and going with a single Revel 15a sub (no way I can afford 2 of those puppies)?
Guess i'm asking if 2 inferior subs are better than 1 great one.
HT is 12x26x8 basement room.

[Sir Terrence the Terrible]

Sir TT,

I have a Def Tech 15" sub...it's nice, but older model. In your opinion, would I be better off buying another identical Def Tech sub or selling mine and going with a single Revel 15a sub (no way I can afford 2 of those puppies)?
Guess i'm asking if 2 inferior subs are better than 1 great one.
HT is 12x26x8 basement room.

It really depends on if you are trying to optimize for one seat or more, and if you are happy with the performance of your current sub.

If you have more than one seat, then you would be better off with 2 subs. If you are trying to optimize for just one seat, then a single sub in the corner will do the trick nicely. That Revel sub is a monster in and a half. It will definately fill that room size easily with deep tight bass. But you can only optimize a single bass module no matter how powerful it is for a relatively tight sweet spot. It takes more than one to cover more than that.

That sub is powerful enough that you could do center of the front wall placement, and create a house curve that counters the LF rolloff a sub would have when placed in that position. It still won't be optimized for more than one seat, but you could avoid exciting any of the most audible modes when you place it there.

[Geoffcin]

Since my reciever will support it, I''d like to add another sub to my HT setup. My setup is all Paradigm monitor series with a single PS1200 sub. I've been quite happy with it but kind of have the "upgrade" bug.
My question is: Do both subs need to match eachother in size/power/LFE? I don't really know what to expect for a benefit from a second and I'd probably use Audessey to help adjust the levels. Paradigm no longer makes the PS1200 so I'd be looking for a used one- or can I get something else? My room isn't large (15x25 plus a 12x10 opening)

Your room is similar in size to mine and I run multiple subs in my setup. It would be much easier for you to get a similar sized Paradigm than to try to match the output of another brand or sized sub. It can be done, but it's a bother that I wouldn't recommend. The only one I would think of trying mix-match is a Paradigm 15" Servo Sub. That sub is extremely powerful and you could run it as the main, and let your 12" fill some of the dead spots at -3dB. The servo sub cannot be driven into distortion and has an output in excess of >105dB across it's range in your room.

http://www.hometheaterhifi.com/volum...05-part-1.html

With your sub secondary you sould be able to reach 108dB or better. More than most non-reinforced structures can stand!

[Geoffcin]

Let's keep the personal sniping to a minimum guys. Thanks!

[Johnny B. Galt]

Thanks for all of the input. I came out with several take-aways. The first being one good sub with proper placement is more beneficial then two inferior subs. So, rather than trying to bring in another sub, I'm going to stay the course with my PS1200 for now. I plan on looking for something bigger and better in the future. Of course, if I happen to come across another PS1200 secondhand, I'll jump on it and then put off the bigger/better upgrade for a little while longer.

[Nasir]

I have checked out a lot of sites regarding subwooofer placement and the preference of 2 smaller subs over a single large growling variety of these beasts!
In theory and for the sake of symmetry, the left speaker and right speaker sides should be mirror images so as not to introduce MORE errors, leaving us with placement techniques and the dreaded room treatments to try to tame the other anomalies. The 2 subs in this case have to be placed so as NOT to reinforce but to minimize the standing wave patterns, otherwise a heavy bass headache will result.
Most cone speakers bow out around the 60 Hz mark, leaving the sub to fill in the rest. Electrostatic and other panel speakers hand over the heavy work to the sub at around 100 Hz. I am generalizing here, so please don´t get upset if your speakers cross over to the sub at different frequencies!! The 100 Hz wave can be localized as to be coming from 1 sub wherever it is placed breaking the effect desperately desired by our lot. Hence, the use of 2 subs removes this localizing annoyance.
So much for rules, but I am married, and the only rules that apply at home are made up by the wife and cats! To start with, nothing is symmetrical in my speaker placement and the recommended speaker to wall distances have been ignored in favor of me sleeping in the matrimonial bed instead of on the sofa. I have Electrostatic speakers, so the need for a second sub became evident quite early on. I am using a 2nd sub that is a lot different from the Final Sound sub that came with my 300i panels. Obviously, it took much longer to set up and the test tones easily distinguish the better sub, but for music and movies I am rewarded with a more enveloping bass than with a single sub setup.
Hope to have been of help.....

[Sir Terrence the Terrible]

I have checked out a lot of sites regarding subwooofer placement and the preference of 2 smaller subs over a single large growling variety of these beasts!
In theory and for the sake of symmetry, the left speaker and right speaker sides should be mirror images so as not to introduce MORE errors, leaving us with placement techniques and the dreaded room treatments to try to tame the other anomalies. The 2 subs in this case have to be placed so as NOT to reinforce but to minimize the standing wave patterns, otherwise a heavy bass headache will result.

The problem with this theory is that it requires a sub to be placed in the center of the room, suspended equally in between the floor and ceiling not touching any surface. I do not know many that would be comfortable with that set up. We have not even mentioned the complete lack of low frequency support that set up would have.

Most cone speakers bow out around the 60 Hz mark, leaving the sub to fill in the rest. Electrostatic and other panel speakers hand over the heavy work to the sub at around 100 Hz. I am generalizing here, so please don´t get upset if your speakers cross over to the sub at different frequencies!! The 100 Hz wave can be localized as to be coming from 1 sub wherever it is placed breaking the effect desperately desired by our lot. Hence, the use of 2 subs removes this localizing annoyance.

Two subs crossed over at 100hz would not exactly localize at exact locations, but you sure would know if they were both located at the front of the room, or in the rear of the room. If you split them up into front and back placement, you sure would know exactly where they sound is coming from. 80hz and below is a safer bet for both saving the smaller main speaker, and for not giving away the subs location.

So much for rules, but I am married, and the only rules that apply at home are made up by the wife and cats! To start with, nothing is symmetrical in my speaker placement and the recommended speaker to wall distances have been ignored in favor of me sleeping in the matrimonial bed instead of on the sofa. I have Electrostatic speakers, so the need for a second sub became evident quite early on. I am using a 2nd sub that is a lot different from the Final Sound sub that came with my 300i panels. Obviously, it took much longer to set up and the test tones easily distinguish the better sub, but for music and movies I am rewarded with a more enveloping bass than with a single sub setup.
Hope to have been of help.....

On one hand it is great to be married, on the other not if you are a video or audiophile.

[E-Stat]

So much for rules, but I am married, and the only rules that apply at home are made up by the wife and cats!

Fortunately, I was able to train mine from day one. She moved into the house I had purchased while still a bachelor with the system in place. E-Stat's low-WAF environment circa late 1985:



That tapestry draped over the stair rail behind the couch became my first room treatment when I hung it on the back wall. We later the finished the basement which became my first dedicated listening space. The other two houses we've owned since that time were chosen as having a dedicated listening room. Other than the audio room and the garage, the rest of the house is hers.

rw