Do i need two subs in my room 13 by 24.5 i am about 10 feet from the listeing position My M22ti are about 6 feet apart.

The short answer to your question is no. One sub that is powerful enough to match your other amplifier output and keep up with your room size will work just fine. This being said, I personally am a big fan of multiple subs. Two smaller subs in medium to large rooms can have some great advantages from the point of view of getting just the right amount of bass at all the various listening positions. It takes a bit of experimentation to get the sub placements and volume settings correct in your particular room, but it really works well. The other benefit, which can also be achieved by just having a sub that is bigger than you really need, is that the source material is not all recorded the same and some times you need to turn up the sub to get a proper balance of the low frequencies to the rest of your system. This is especially true with some Home Theater recordings and much less so with stereo.

Ok, this sounds (sic) great.. I'm a big fan of the 'multi-sub' concept.. I have experimented a bit with this, but could only afford the 120 watt 10 inch KLH's... What the heck, eh.. For 99 bucks each at Costco, makes me feel like a real "A and B" high roller.. :-) My question would be, if running more than one, do you stay with the recommended single size speaker, or drop down one size ?? EG: If room/system would normally run a 12, do you go with two 12's, or two 10's ??
The 12 moves more air, but the 10 is tighter, eh.. Two 12's too much, two 10's not enough ??
I will probably go with a single 12 and add the 2nd Twelve as funding allows.. But if two Tens would be better and more easily controllable, I would go that route..
One last thought.. Does it make any since to have a 12 and 10 combined in the same system ? Similar to multi size med's and woofers in a tower, eh...
Gotta love it.. And I do... thks..

Hi Grank It Up,

You could combine a sub with a 12-inch driver with a 10-inch-driver sub--it depends how much bass extension and output you want. If anything, the different characterisitics of the two subs (they won't be identical in the rate of bass rolloff, or distortion, or deep bass extension) might be complementary to each other.

But the real virtue of two subs, as Ian pointed out, is the ability to smooth out bass response over a broader listening area than would otherwise be possible with one sub. Standing waves with nodes of bass cancellation and bass emphasis are an inevitable product of any room (a room with square dimensions is the very worst to generate standing waves), and using two subs is an effective remedy.

Regards,

This could be a debatable point as you posted. Frequency waves generated by both subs would have identical wavelenghts at the same frequencies. By placing 2 subs in the room, the addition and cancellation could be extrapolated to the combined waves. Each sub could either cancel, or reinforce the others frequencies. I would think this would require careful placement to eliminate this.

Perhaps a front set offset from each other, or front and rear offset pair. It would an interesting experiment!