KLH HTA-4906 System "surround sound back ground noise" Questions

...sound will come out. Receiver settings are for a subwoofer to be connected. I get a "humming noise when the jack is partially conneceted but goes away when fully connected. What can be the problem? ...

...surround sound system, powered subwoofer make sure you have the speaker connection right if you do then it is a ground problem try plugging it in a different outlet Check the back side of your ...

...sound. This can easily be fixed by adding a switch to disconnect the mains earth from the back plate, or you can just unscrew the earth and tape it up, this fixed my ground loop, (some models already ...