2 subwoofer???

I tried 2 subs with my B&W matrix 804's and they added a depth to the soundstage that was unknown to me before. I have since switched to Legacy's Focus 20/20 which is like having 2 subs in a speaker. Definetly an improvement over 1.

Virtually all CD's are mono below 80 Hz, so I doubt there would be a significant audible difference between dual mono subs and dual stereo subs.

I do believe that dual subs offer significant room integration advantages over a single sub.

From my investigation of the subject, there seems to be two well thought-out schools of thought on dual subwoofer placement. One holds that the ideal is to place the subwoofers to the extreme left and right of the listening position. This maximizes the interaural time difference and thereby the sense of spaciousness that the subwoofers convey.

The second school of thought recommends what could be described as highly asymmetrical placement, to maximally stagger the path lengths from each sub to the room boundaries and the listening position. This results in the smoothest bass, and is the technique that I use most
often.

Duke

I run a pair of Def. Tech. Cube II's with my monitors to great effect, clean, fast, controled.

In my experience 2 subs are better than one. They must be identical and in many cases should be placed at the near the midpoints of the room to help control room modes. They are difficult to set up without a tech with the proper equipment to help you,otherwise the placement is really by chance and you probably will not get the most for the money. That being said, properly setup stereo subs sound awesome indeed.
Good listening,
Sgr

Hey Duke, can you expand on your "second school of thought" comment above. I run dual subs and am all ears on set-up advice. You too Sgr and Rives. My primary concern is 2-channel audio even though I have HT in the same installation.

BTW Uru975, the bottom end of the Focus 20/20s is tough to match. I was a very happy owner of a set before getting Whispers. Even for HT, there is no need for a sub with those speakers...just lots of amplifier current!