I have a HT room about 9x15x8 It is about 1180 cubic volume, I think. The HT room is setup with my in wall speakers and furniture and moving things around is not an option. The tv is directly in front of me with 2 svs pb-12plus/2's They are monster subs especially in that size room. Anyway on to the question. I am probally canceling each sub out since they are on both sides of the tv. But i will not move them because of looks. Is there some type of equipment out there that I can hook up so it stops the subs from canceling each other out? Thanks

At the very least get them out from having a TV between them (if this a large TV or in/on cabinet etc), or move the TV, then try adjusting the phase on the subs.

Unless you have the phase reversed, they are not cancelling each other out. Did you check the phase settings?

I don't have the phase reversed, but I was always under the impression that if you have 2 subs on the same wall in each corner, together they will cancel each other out. And thanks alot for the help.

I don't have the phase reversed, but I was always under the impression that if you have 2 subs on the same wall in each corner, together they will cancel each other out. And thanks alot for the help.
If they are in phase properly they won't cancel each other.

Try unplugging one or the other and see if that improves the sound. If that works, buy a dead copy of what you have now and sell the good one.

You'll still have the balance you seem to need.

Two subs are a royal PITA. Especially when you don't want to move one of them.

I don't have the phase reversed, but I was always under the impression that if you have 2 subs on the same wall in each corner, together they will cancel each other out. And thanks alot for the help.

What happens when you have loudspeakers that are spaced is you get cancellation AND addition. It depends on the freq and the spacing. It will vary all over the place and will vary with the listening position. For example at one seat you may get a cancellation at 50Hz and at another position you will get an addition-because the subs have different path lengths to different listening positions.

In most cases unless you have a LARGE TV think 10' wide AND you are sitting way off to one side, you should not have any cancellation going on, on addition-due to the long wavelengths.

At higher freq, yes you would get some cancellation-depending on your seating position relative the distance between each sub and your seat.

In the middle you should get only addition-since you are the same distance from each sub.

Are you saying that if you have only one sub on it is X loud and when you turn on the other sub the level decreases? If this is the case you either have a defective sub, a wiring issue or a setting difference of some sort.

When you add the second sub, it should get louder. If not, do not look for some special technology, but rather what is wrong with your setup.