The Dude,

Have you actually tried your receiver with the M80's? I bet that most decent receivers will actually tolerate the M80's, especially given its high efficiency (meaning, less average power required). For example, even though Pioneer does not officially support a 4-ohm speaker, my Elite 45TX receiver is humming along with my 4-ohm Hales at pretty high volume levels. I believe that Denon officially supports 4-ohm loads with their mid-priced receivers and higher. But I would first try it with your existing receiver.