I've had a 45TX for about 6 months now. Up until recently, normal listening levels (i.e., with my wife in the room!) were in the 36-33db range - maybe 30. By-myself levels were 27-24db, maybe 21-18db if I was going for broke. About a month ago, I changed my sub (built an Infinite baffle). Ever since running the MCACC, normal "wife-approved" levels are now 27-24db. (Right now, we have Chicken Run on at 21db, and it still could not be considered loud.) I did not keep track of MCACC levels until after changing subs. (I have since made a simple chart to easily record all the levels.) I suppose the most relevant would be the channel level. Here are my current levels - they have all been relatively similar since I've started keeping records (4 different MCACC's): Frnt - L: +8.5 Cntr: +7.5 Frnt - R: +8.0 S - R: +2.0 SB - R: +8.5 SB - L: +10.0 S - L: +6.5 Sub: -4.5 BTW, I reset the unit to factory defaults before the last MCACC (which is the one listed here). I know I can just turn up the volume to whatever level now works. But, I cannot help but wonder what the difference is. And, I'm not sure I'm getting everything out of my sub that I should be getting. (I'm told my Bryston 4B should be bottoming my 2 15" drivers, but it clips first instead.) The different volume levels make me wonder if the dynamics of the receiver are somehow limited now. Any help would be greatly appreciated. Steve V.