I'm wondering if such a product exists. I recently moved into a new house where in the upstairs great room is tiny system with in-ceiling speakers. The equipment area has dedicated electrical discrete from any other circuits yet I'm getting a hum from the speakers. It seems to be related to when certain dimmers are on. I had expected ground loops or interference would not be a problem with the dedicated circuit. Is there a filter that I could install at the breaker panel for the dedicated electrical that would eliminate this? Other suggestions? Thanks.