I have a Denon AVR2105 (90W/channel) in a 4000 cubic foot room. I sit 8 feet away from the M80s. For music, I have the Denon set at about -25 which is less than a watt per channel. For movies, I have it set at about -15 or -20 which is a few watts per channel. Put your money to an EP600 instead of a monster amp unless your cathedral ceilings are 30 feet tall. I hope this helps and happy listening.