If you are going to do the calibration manually with an SPL meter you need to use the channel test tones. While the test tone is playing on each channel adjust the channel trim until the SPL meter reads 75db. The channel trim level for the subwoofer should be at zero in the AVR. The subwoofer volume should be set with the gain knob on the back of the subwoofer. The subwoofer should be adjusted to output between 75db to 80db with the test tone playing. Also keep in mind that the SPL meter needs to be set on C-weighting and slow reading. You could just let MCACC do this for you and check the results with the SPL meter.