speakers/sub

Your room is really quite small for a sub in general. If anything, I would suggest a REL (which is one of only a few sub brands I would even consider). I used to own a pair of T3s ($250-300 used) which do well in a smaller room and stand speakers that have limited LF extension.

The reason I recommend one of these smaller RELs is that I think most of their bigger subs will overpower your room and possibly even extend too low. At your room size, my goal would be simply to extend down to about 28-32 hz. and do so with a smaller driver (8" in my mind).

I have to be honest though and suggest that you would probably be better served by stepping up to a better performing integrated amp. Since I am no expert on integrated amps, I don't feel right recommending a specific one as I have limited experience with them.

Drew, that's odd, when I tried the "learning" subs (velodyne specifically) when I had a system in a very small room in the basement my experience was that sure some manipulation could affect performance in specific areas (frequencies), but the sub just wasn't very good.

Applying filtration to a sub that just doesn't produce a strongly musical sound performance and the ability to stay caught up with my speakers (at the time a pair of Wilson Audio Duettes) didn't do it for me.

All the digital manipulation didn't make up for a somewhat lacking sub in the first place.

My recommendation is to find a sub that has high performance characteristics and good speed, whether with or without all the digital filtration/adulteration components built-in.

A finely tuned Yugo is still a Yugo and no matter how good of a condition its engine is in, it's performance will always be limited.