Receiver Auth

Receiver Auth

Why does my subwoofer hum when any device that's connected to my TV is connected to my receiver?

I own a Sony STR-DG500 6.1-channel receiver, a Cerwin-Vega active subwoofer, and a Sony 55" 1080p SXRD projection TV. When I connect ANY RCA cable (digital OR analog connection) to the STR-DG500 that's connected to a component that has any sort of connection whatsoever to the television (DVD player via analog stereo OR coaxial digital; cable box via analog stereo; even my iPod via a docking station, if the video connector is connected to the TV) I get a horrible hum through my subwoofer. If I use an optical connection or disconnect the component from the television, the hum goes away. If I connect an audio-only device via any connection, there is no hum. Hum persists regardless of subwoofer phase, volume setting, or crossover freq. Any ideas would be appreciated - amp and sub have both been in for warranty service, but problem persists despite assurances from the local Sony-auth. shop that the problem was found, diagnosed, and repaired. Thanks.

What your hearing is most likely a problem with your grounds. Is your sub plugged into the same outlet as the rest of your system using a surge or power conditioner. If not you should look into getting one. If the sub is far away from the tv make sure its at least on the same circuit as the tv. You can also try turning off that circuit and pulling out the outlet and tightening down on all the screws that are connecting the copper to it, over time they do loosen up some. Worst case, you can use a ground lift bought at any hardware store to lift the ground on the sub or tv and that will also probably clean up the hum. A warning if you do this though, by lifting the ground if the device shorts out the outer chassis of it will become charged due to no ground being attached so dont touch it until it gets unplugged, its a very minor chance of that happening but it can.

Tagged with: audio • dish network receiver authorization • receiver auth

Filed under: A/V Receiver

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