One more thought as you're doing all this set up work...
Check this out:
SPL calculator
One thing to keep in mind though for amplifier power is what you are getting
all channels driven. So your SR7012 isn't actually giving you 110-125w per channel... that's only 2 channels driven (stereo listening). If running 7-9 channels, you are probably only seeing ~75-85wpc.
I use the SR6012, and when my speakers finish arriving next week, I'll be juicing them with external amps... by the time my Phil-3s arrive in May, I'll be running 11 channels, and will have 5-channel audio powered by external amps, with the Rears and .4 Atmos driven by the AVR.