Quote Originally Posted by 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)
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.