Seeing how you are drafting the house plans now, is it possible to move the rear wall to give you a few more feet in depth?? My HT is 12 X 16 and I sure wish it was 14 X 18. At least yours is 14 wide, which will give you enough width for four seats across the room (if desired). I think the 13’ depth is going to drive you nuts and you probably will not have enough depth for a projector, if you planned to go that route.
Regardless of room size, stick with 7.x. The trend for movies lately is to have 7.1 channel mix. It’s better to have a few feet behind your listening position for the back channels, but any amount will work. I have roughly 3' behind my listening position and I just can’t imagine not having the QS8’s behind me. I tried 5.1 just for grins once and went into withdrawals in short order. It’s better to have more distance for the back channels, but the Q’s will work well with anything you can give them.
For the center channel, the 180 is more than you will need, but who really cares?? I’ve never heard anyone bitch and complain about excess but they sure do bitch and complain about not having enough. I’d go for it if I were you. Screw the little book shelves. I’ve gone down that road and ended up with two M22’s under my screen and then ended up adding a VP150 above the screen to play with the 22’s. Now I’m happy. If Axiom had a center speaker somewhere in-between the 180 and 150 in physical size, I’d have two of them. One under and one over my screen.
You choice of subs is a good one and the same combination I have. I did have one EP600 in my room, but it was just too damn big and it stuck out like a sore thumb. I swapped it out for two 500’s and I prefer the 500’s over the single 600. I would suggest one slight change to your plans though. Buy one 500 now and give it a whirl. If you find it lacking, buy a second 500 later. I can tell you with absolute confidence that you will be quite happy with one 500 in a room your size. After time, when the honeymoon bliss wears off, you may start to feel like something is missing in the LFE channel. At that time, buy another one.
In the end, it’s your money and your decision to live with. Just about any combination that has been suggested will put a smile on your face. But I am quite serious when I suggest that you stretch that room of yours. That’s the one thing you can not ever change, and speaking from experience, it is the one thing you will wish you had changed.
