Well I used one of the M80 rears as a center over the weekend and played with location. To my ear I could not hear any noticable differance with it 2 feet from the existing cabinet or if it was less than a foot from it. So the plan is to go with the sliding shelf, and this will allow me to slide it out as much as a foot if need be. Hopefully I will not need to re-engineer the cabinet again. lol

ROCK 'N' HAXIOM Theater