I can't speak for everyone else but mine really opened up using the 3/5 ratio back wall to side wall. Both measurements are to front side middle of the tweeter. I have mine toed in where they are firing just to the left and right of the MLP not directly at it. Every room is going to be different but this is the general idea. Mine are pretty much invisible and the soundstage and imaging is incredible. Certain songs you'd think all of the surround channels were playing. The dsp separates the front and the back speakers in the passive 1100s so the sound doesn't cancel each other out or cause weird wave effects. I'm sure others on here can be much more specific but that's the general idea. I would continue adjusting the speakers or maybe even your MLP if you can. 6 feet apart at 10 feet listening distance feels like the speakers might need to be a littler farther apart if you have room and not get too close to the side walls.
