Sub "humming" (1 Viewer)

[Leigh_M]

I went to wire a new system in my parents new house. The house came pre-wired for 5.1 surround. The sub wiring put the sub on an adjacent wall. When I plug the sub into this wire connection and outlet, I get an awful humming sound. I get this sound with or without the receiver connected. Connecting the sub directly to the receiver using the same short cable produces no humming. I'm guessing the installer used un unshielded cable. Any other thoughts?

 

[Steve_Wingman]

It could be the power outlet's grounding or a ground loop. When you have the sub plugged in to the wall without the lfe line in connected, it still hums right?
-Steve

 

[Steve_Wingman]

QUOTE: "I have the sub powered through a surge protector which alleges to offer some smoothing as well. But yes, when there is no "signal" to the sub it still gives that same regular "pulse/beep" sound with each sound about 10-15s apart. It does the same even when the signal is present."

What happens if you bypass the surge protector and go direct to the outlet? (your post didn't show up for me on the msg board)
-Steve

 

[Leigh_M]

There is no humming when plugged to the outlet but not to the in wall lfe line. It only hums when connected to the in wall lfe line. Also, I used the same cable to connect directly to receiver and no humming. The sound is very steady, no cycling.