You've got about 3600 cubic feet of volume to fill, which is about 600 or 800 more than I have with my LFM-1. For me, the LFM-1 is plenty in my space, and I'd expect it to be similar in yours. A pair of LFM-2's should certainly be able to do the trick for you, but rather than just say "get two!" I'm thinking much the same thing you are - maybe one would do the trick for you. I'd probably get one and see what it did for me. If it wasn't enough, a second ought to get you where you need to be, but (particularly for music listening, where the lowest octaves don't see as much activity as action movies' LFE tracks) that single LFM-2 may very well be just what you're looking for.

For what it's worth, when I first saw pictures of the LFM-2 from last year's HE show, my first thought was, "An RR2150, a pair of nice monitors, and an LFM-2 could be a killer music setup." It really does seem like a well-suited combination, especially when you factor in the LFM-2's price tag.

If you do give the single LFM-2 a try, I'd love to hear what your experience with it is - it could help others with similar decisions.