I have the (lowly) 45TX. I run the MCACC, which sets my front speakers as "large." I then manually set them as "small." You don't have to rerun the MCACC, since it will automatically reconfigure itself when you re-adjust the speaker settings. I do not tweak the level/delay/EQ parameters given by MCACC at all -- in fact, I once tried and quickly learned that it is darn hard to beat the MCACC.