Dick,
I have a 16'x16'x 8.25'H room, with a fireplace/chimney protruding at front wall center. The speakers are about 3' out from the front of the fireplace, and there are cavities to the sides of the chimney which effectively extend the distance directly behind the speakers to 5'. I listen on a couch against the rear wall. So the distance behind the speakers is pretty good, but the listening position against the rear wall is suboptimal but necessary in order to position the VSMs the desired 9.5' from the listener.
I experimented with acoustic treatment between the speakers, and found that 80% results can be obtained by hanging a 1.5'H x 5'L band of sound absorbent material on the front wall at ear level between W & T. I used a Navajo rug covering some Cornertunes (IMO never much good when placed in the corners for which they are designed). Hanging a blanket floor-to-shoulder height added just a bit more clarity, or "contrast" as Bobby said.
Finally, on a spectrum analyzer in this room I have measured flat bass response on the VSM-MX +/-3db down to around 30hz., with audible bass all the way to 27hz. But the bass is so clean that sometimes you don't realize it's there, relative to the warm, distorted bass of some other designs.
I also have a TSM-MX used in another system as a CC speaker. It is a damned nice CC!
My apologies as well for moving off topic.
Dave