I have tried several positions of the mains in relations to the side wall and back wall. Currently they are 2 feet from the side walls, and about 2 feet from the back wall, and are 7 feet apart. I found that the minimum for good imaging and stereo seperation is 6.5 and the max is about 7.5, after that I lose the cohesiveness of the image. Now, I did catch in your post that the same distance from side and back is not a good thing.. I remember reading that, it re-enforces something or other ? anyways, I'll experiment some more with moving them away from the back wall. I don't have much more play in the side walls, but the back wall I can go right into the middle of the room if need be.
It's been many months of tweaking, moving things around, trying every crossover option I have, putting up traps, trying blankets on the wall at different locations like back of room, front of room, frz, floor etc..etc..I have done a LOT of experimentation but alas..hence my call to the pro, but before I head down that path I'm going to want assurances that it "will" fix the problem and not create more !!! my room size will diminish by almost half with the wall..so that may introduce more modes as they are typically more apparent in smaller spaces..I don't know..I did not get "all the answers" from my consultation session that I was hoping to get.
The reason I paid $200 bucks to have that guy in was to stop taking shots in the dark and get someone on site to evaluate the situation first hand. I was expecting more I guess, maybe my expectations were unrealistic.
