John, is it a possibility that on some older receivers like my Scott 335,circa 1985 or so, that there might be any difference in sound because there is no audio direct buttons and that perhaps things such as the treble and bass may not be totally taken out of the picture. Also, there is a subsonic button on the unit which seems to really make a difference when hooked up to my M80's as opposed to my M3's. Not looking for an argument on the issue, just curious. My old Scott at 35 watts per channel sure made my M80's sound good, and took them to uncomfortable levels without any distortion that my untrained ears could hear. Only listening at 10 feet from the speakers. Although it did sound great at about 30 feet away while listening in the kitchen. Just not as loud.
