Use the included MIC to run Audyssey MultEQ XT. This will set the trims to make your speakers close to 75db and will do wonders for your overall sound. After running Audyssey, you should manually set your crossovers if the Onkyo sets any to FULL.

The included test tones are -30db. This means your meter should read 75db when using the tones.

Dave
Audyssey Setup Guide