Cardas Speaker placement..

parallelAll systems are starting points only. I have used the Cardas and then moved the speakers closer to the side walls. My GamuTs come with a formula that is complex enough for an advanced math class; I can't get them as far apart an they want in my room anyway. My room is 13'x35'x7' so I understand your problem; I would move them in at least 2' from the sidewall and possibly place sound treatment at first reflection point. Actually, I would treat the room no matter where I put the speakers.

I agree with Phil; I use 6" corner traps and 2 4' x2' x4" panels lying against the wall and the increase is bass very noticeable. See my system which is listed under my threads.

Without treatment the reflections reinforce some of the higher frequencies and cancels others. Makes the sound seem "louder" but when you listen carefully there are things that just aren't there that you hear with treatment. I occasionally take everything but the corner ones out just to check; I leave them in as they are screwed in, the others just hanging. With the treatment music sounds "softer" but there is actually more treble if anything; just a lot more even in character. There is definitely more bass with the panels; get a lot of cancelation without them. In a smaller room reflections are a much bigger problem than in a larger one.