ok folks. Ive seen quite a few subwoofer is humming threads but my situation might be different.
I have two different setups in the house. In the living room there is a small powered sub in that system. I have no hum issues with that one at all.
Upstairs there is the "main" home theater with a larger sub and it hums at all times when on. Even with no cable connecting it to system. I tried disconnecting cable to the house to see if that would kill the hum. No dice. Still hummed. My next project is to take the small sub out of the living room and plug it in upstairs to see what happens and perhaps bring the big sub downstairs and plug it into the system that is not currently humming to see what happens.
To subs go bad? This is an SVS and is about 5yrs old.