not sure you answered my question, what mode are you using: direct, stereo, PLiix, etc? My m80's are seperated about 9-10ft in the theater room, front row is about 8-9 ft back, and 2nd row is more like 13-14ft, and there are no issues. The m60's should be as forgiving as the 80's.

my guess it is a room issue, what is your floor and walls like? if you have hard surfact floor, try throwing a carpet piece or something between you and the speakers.

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