I have found, through hours of experimenting, that my M80's require 12" clearance from behind, and about 9" from the side wall. It would be helpful if the M60's could tolerate less clearance, like six inches. Just how much distance do you have between the walls Chess?
Well, we have a subwoofer on one side of the M60 toward the wall and on the other side we have an audio rack.
So distances from the side walls is in the range of 2-3 feet. Distance from the rear wall is pretty much set based on the TV depth and i always wish i had just 2 or 3 more feet to play with in this regard.
I've never been too concerned about the distances, but in a smaller room, much closer to a wall, you could notice a small boost in sound reflections and bass (maybe).
It is hard to tell since you cannot simultaneously move a speaker and listen to it in two locations instantaneously.
I would be inclined to trust a frequency response measurement at a fixed location instead.
