Axiom Home Page Forums General Discussion Home Theater Can't kill the humming in my sub..help

His #5 seems to indicate what removing the input from the receiver does indeed stop the hum. So it is a ground loop, just an extra pesky one.

I'd say, while it is humming, start unpluging things from each component, and then components themselves from the wall. When it stops humming note what you just unplugged. You can then try plugging some of the other stuff back in, and see if it does not return. Report back here with your findings for some ideas.