Pierre,
Here is the follow-up on your comments on the Quads 2905 you posted on my system page:
I'm sure the 2905s sound good; I haven't heard them yet, but I love my 989s and from what I understand, they're not all that different. I wonder if they really wouldn't work in your room. My room is L-shaped, but the portion I use for listening is 11' wide (same as your width); length is 23' but I use only the front portion of that length. The point is that 11' of width should quite workable with the 2905s, if you can fit them along the shorter wall; those speakers can be placed practically against the side walls because there is nothing (phase cancellation) coming out of the sides. You would have them ca. 7' apart (from the center of the panels).
I see that you're having your speakers currently on the long side; that's the way I heard the 989s originally at the dealership where I bought them. They worked fine like that, because those speakers are great when heard practically near-field, as long as you have them 4-5' from the wall. I'm not sure what the opening on the right side of your diagram is, but the speakers would end up almost in front of it (if it's a window, no big deal).
Your room looks a little tricky to work with, but, alternatively, I don't know if you can reconsider your layout to have the speakers against the shorter wall, at either end (you could perhaps still get in your media room if the speakers are 4-5' from the wall--is there a door to that room? if they were on the other side, they would be on the outside of that opening you have there).
Either way, I wouldn't give up on the idea, if you like them enough to give them a try. That's my experience with them, at any rate.
Cheers,
Joel

jfd01 June 29, 2008 02:59