In reply to:
Sushi how can a 110 watt "receiver amp" at 0 put out 3db more volume than a 200 watt Adcom amp at 0?
Your suspicion is warranted If each power amp is supposed to be designed so that its rated max available power is reached at the same input voltage from the pre-amp. But in reality, this is not the case -- as John indicated, there is no "industry standard" for the voltage gain of a power amp. It is not unusual to see +/- 3dB or so of volume change when you switch the power amp.
But this (non-)issue is totally separate from the possible problem that you described earlier regarding the sub calibration. So, after running YPAO, does the sub put out approximately the same 75dB on the SPL meter when fed with a reference tone? After YPAO, how does the entire system sound with a music source, including the sub? Is the sub overtly too "cold" or too "hot"?
