OK, I see two things to think about so far :
1. The basic dimensions of the room (square) are going to be a bit of a challenge in terms of room modes, although the bevelled roof, the bookcases, and the openings in the west wall will definitely help (and half a cube is way better than a cube
).
Your main challenge is going to be a big response peak around 56 Hz.
2. If I remember correctly you have windows on the east wall and openings on the west wall. Assuming you leave the furniture oriented as it is now, you're going to need some VERY heavy drapes or equivalent over the windows on the east wall to keep the side reflections "balanced" and get nice clear imaging.
On the other hand your planned speakers are a good size for the room and the M60s sound great when they're pulled away from the wall. If I didn't screw up the math, you may find that pulling the M60s a few feet away from the wall (fronts 5' from the wall and 5' from each side wall) will tame that nasty 56 Hz peak. I haven't had a chance to do a lot of tinkering with this stuff though, so (a) don't worry too much about the bad things I'm saying and (b) don't get your hopes up about the good things. On the other hand, if I'm right about one I'm probably right about the other
Gonna wait for the rest of the posts now...
John
