I am surprised that you had not noticed your speakers set to small earlier on.
My preference is to use the full range of bass from my M60s and to keep my sub for only the low range rumble noises of home theatre (hence turning my sub crossover down to the 45hz-50hz setting). I did find however that moving my sub to the back of my listening area caused some problems with timing and general quality.
Changing the phase switch on the sub did not make any difference.
Have you noticed any muddyness in the bass since you moved your sub?
