Hello all, I have a Velodyne subwoofer attached to my receiver. I have noticed lately that it is making a humming sound (or just a low bass sound) even when the receiver is off. I did not notice it before. I have turned it off for now as I found it a bit annoying. It's the kind of subwoofer that is plugged directly into an outlet. It has an on switch and an auto switch. In either mode it was still emitting the humming sound. I had to turn it right off to stop the humming. I have not figured out how to make the auto switch work. I was assuming that auto meant it would only go on if the receiver is on, but that was not the case. Unless I'm supposed to hook it up a certain way. Any advice appreciated.