Things to try:

1. Turn off Audyssey
2. Select a different Audyssey setting if equipped e.g. movie vs music curve
3. Set M80s to large
4. Bump up the bass
5. Lower the treble
6. Bump up the LFE gain
7. Play with EQ settings if equipped in the receiver


House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated