I have an LFM-1 and 1050, and in really hot weather I get a loud hum coming from the subwoofer. If I turn that off, I still hear the hum in the speakers. Again, this only happens in hot weather, and it doesn't seem to be any particular component causing it as I've tried the old "unplug everything until you find the source" trick. It tends to happen even if my AC is off, so I'm thinking it's something with my refrigerator, but I could be way off.

Any ideas?