My Denon mic setup also gives me slightly different results than my SPL meter when I calibrate to 75dB's.. I'm not sure when the receiver runs its tests what dB levels it is trying to achieve?

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85