Neo, you have not described your setup, I assume your using surrounds? If not, is it possible the surround channel is being routed to your 80's? Are you using Dolby or DTS modes? etc... speakers set to small?

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85