moto man,
My perspectives tend to be about 3 3/4 feet from the back of the speaker to the wall behind them. Left speaker about 2 feet off the side wall, the other speaker near a room opening.
I haven't played with the speakers much closer to the back wall because I have a bit of an unusual room demands that forbids such placement as permanent (the right speaker is near the room entrance and placing the speaker closer to it's back wall actually puts it in the pathway of entering the room. In this case this "limitation" works out fine as most speakers work really well in the room at that distance from the walls.
My perspectives tend to be about 3 3/4 feet from the back of the speaker to the wall behind them. Left speaker about 2 feet off the side wall, the other speaker near a room opening.
I haven't played with the speakers much closer to the back wall because I have a bit of an unusual room demands that forbids such placement as permanent (the right speaker is near the room entrance and placing the speaker closer to it's back wall actually puts it in the pathway of entering the room. In this case this "limitation" works out fine as most speakers work really well in the room at that distance from the walls.