@brotw posted: " As I understand it, an array of subs would be very effective at smoothing out the bass response of the room over a wider sweet spot. What about spatial cues from bass frequencies? "
The good news is, you can have both.
My understanding is that true stereo below 80 Hz is actually quite rare, but if you want the ability to reproduce it, then (assuming four subs total) send the left channel signal to the two subs located towards the left-hand side of the room, and the right channel signal to the two subs located towards the right-hand side of the room.
If you’d like to synthesize the sort of immersive ambience we might get from true stereo bass, try this: Set the two subs on the left-hand side of the room both 90 degrees apart in phase from the two subs on the right-hand side of the room. So for instance if the two left-hand subs have the phase control set at 30 degrees, the two right-hand subs would have the phase control set at 120 degrees. Credit to David Griesinger (inventor of the Lexicon processor) for this idea; his original suggestion was to use two subs, located along the side walls to the left and right of the listening area. That 90 degrees phase difference isn’t necessarily carved in stone either - you can go beyond 90 degrees, at the expense of increased cancellation at the very bottom end (which in some cases may be desirable).
Duke
(disclaimer, in case the connection isn’t obvious: I make the Swarm)