Dean, I think you should try a seperate amp to drive the M80s, the bass I could get from them with the A1400 was incredible and it had alot of impact, much more than with the 3808 alone. The extra power from the seperate amp makes a much larger difference with the mid bass on the M80s than anywhere else, go for the A1400-2 ;\) \:\)

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70