I had that AMP a month ago and have the M80's.
I think as Alan said , if you ran Audessy it is set for 60hrz crossover and LFE.
I would check the settings and set to Mains and remove the LFE.
Also, I too notice even when I did the Audessy setup, that dial I had to crank it up to get any volume going -15 -10 db and when watching a movie about 0db or +5.
if you go into the setting on the levels for individual speakers you will probably find they are all set to -15 or lower.
I boosted these up about 5 to 10 db closer to zero then when I turned up the amp at about -20 things started to happen and at -10 it was quite sufficient.
By contrast, I ended up getting a HK3490 as right now I only have the two M80's and subs while my room is being built. I turn this up the other night listening to music and at 0 bd on the dial, listening to Luke Bryan song then one that goes boom boom ( sorry just recently started to listen to counrty ) there was extreme air movement in my living room
