Thanks for the link Hutzal, I will most likely end up using this method if I cannot find anyone to trade 1:1. Unfortunately the M80s only give about $350 credit towards a pair of M60s. I may add some QS8s to get the full trade in value, though I don't know if I can justify spending the extra money at this moment.
Terzaghi, my father and I both use Onkyo receivers. I own a 304 and he has a 605 (unfortunately no pre-outs on either model). Both receivers ran quite hot when using the M80s so I removed the speakers from the theater room to prevent any possible damage (and also because the cherry finish clashes with the entire room). Right now we are using M22s as mains, but the room is rather large (31x14x7) so an M60 would likely be the best fit - also because it's 8ohms.
Right now the M80s are in the living room running in stereo on "small" speaker mode on an older Yamaha receiver. No problems, but I would really like to be able to crank them up while watching a movie in full surround.
PS I apologize if I violated any forum rules. Mods, feel free to delete this thread if I have.
