Ok, first with the acknowledgements: needs room treatments, darker paint, blackout curtains, take down the framed art, thoughtful sub placement (not sure if the PC-2000's can move, but the third sub can be placed using the Geddes method- time will tell on that one), etc. The paint is going to stay the same- I pretty much never watch movies during the day. When I have time I'll build acoustic panels. Blackout curtains will be the first thing.
The room dimensions are: 11.5'w x 16'd (not including the recess in the front), and the ceiling vaults from 8' to 9.5', with the left, center & right portions covering the same distance laterally. The mains are 8" off of their adjacent walls, and are spaced to form a near equilateral triangle with the mlp (they have 3" rear ports- I know the placement isn't ideal in relation to the walls, but it satisfies the minimum distance from port to wall that Gene has mentioned). The surrounds are right at about 12' back, placed about 2' behind the seats, at 5' high.
I will eventually move the seats up closer and build a riser to get a second row couch. The second row will be a bit behind where the seats are at the moment- basically perpendicular to the surrounds. Assuming an 8"-10" riser, and an average listener's ear height of 36", the side surrounds are just about as low as they can possible be to maintain some elevation for what will be the middle seated position in the back row.
That's what I'm looking at right now. I am liking what
@William Lemmerhirt is saying about 5.3.4 vs 7.3.2 as it might be better overall with an additional down of seating. What "concerns" me is that setting the front and rear heights equally from front to back would have the front firing directly above the front row and the back firing directly above the back row. I'm not sure if this is a bad thing.
Thoughts?
P.s.- I know I could probably find plenty of this info doing research, but my room layout us unique to me, AND I like dialoguing with you guys!