Thanks for posting your experience with this device Mark, it's very interesting. I use a 2.1 set up for my system, for both films and music - well not really 2.1 I guess as that implies a dedicated, filtered bass channel, so I should really say I use 2 channel with bass augmentation.
The single sub is only set to very minimum output and a low cut-off point for music, just enough to excite the room. At this point the effect on presence and soundstage is huge and the projection into the room is a great contributor to the very live sound that I get. I turn the wick up a bit for movies but in either case, just tipping past this point gives me boomy bass, so there I stop.
I believe the reproduction of the lowest frequencies is essential to achieve "real" sounds. Even sounds that appear to have NO relationship with bass, say a triangle or cymbal. I'm sure it's just that our perception of "real" is based on the relationship to the full (or at least wide) frequency range and that deep bass does for high frequencies and imaging clues what a supertweeter does for tighter bass
I just recently found this unit on the BK site at the end of a surf run about subs, but I hadn't realised that you were in fact talking about the same bit of kit. I've heard Velodyne subs with DSP/ microphone compensation and the resulting effect was very clean, clear and desirable. As I'm commited to "2.1" I think one of these is going to be a finger slip away.
PS. Val has gotten to the stage where she sees me on AOS and immediately asks "so what are we getting now then?"