Humming from Subwoofer

[nitinserious]

Hi,

I have connected Denon AVR-X1200W 7.2 channel system. The Subwoofer amplifier is Sony XM-GS100. I observed humming in subwoofer when Denon receiver is turned ON. (no humming when Subwoofer amp is ON but
Denon is off) I tried providing solid common ground to amplifier and AV receiver. however humming is not reduced. When Denon AV receiver is muted, humming stops. I dont know how to remove humming. Overall system details are as follows.

AV Receiver: Demon AVR-X1200W
SUbwoofer Amp: Sony XM-GS100
Subwoofer Power supply: SMPS 12V/30Amp


Thanks/Nitin

 

[SS4927]

Try a different signal connector. Subs seem to be finnicky for some reason. I've had RCA wires work perfectly well on everything but subs. Or the wire might be toast.

Also try isolating the sub's signal wire. As good as some of them are isolated by there jacket sometimes you can still introduce interference when an AC wire is touching or just too close.

Is there a cable box connected to your system by any chance?

good-luck

 

[nitinserious]

There is cable box connected. Let me disconnect cable box and check once again. Let me also try combining/tying power cables together and audio cables together and keep a distance and check.

Any specific precaution to be taken on connecting cable box?

 

[SS4927]

Any specific precaution to be taken on connecting cable box?

Both could be contributing to the buzz your hearing, wire in close proximity and a possible ground loop through your cable. Read here https://www.audioholics.com/home-theater-connection/ground-loops-eliminating-system-hum-and-buzz

 

[nitinserious]

One more information, the car amplifier smps supply for subwoofer is 3 pin socket with its body connected to earth. Rest of the all devices connected hand 2 pin sockets. Will it contribute to humming?

 

[nitinserious]

Just to conclude, I am able to get rid of irritating humming. After trying out many suggested options, finally the problem lies in not perfectly grounding all connected devices. The Denon AV receiver is connected to STB and Sony Blue Ray player via HDMI. I used low guage copper wire (from old water heater) and inter connected tightly all the chassis cabinets with this thick copper wire. Also connected this grounding to subwoofer amplifier ground and the the magic happened.....Subwoofer gone completely silent for humming. Thanks all of your suggestions. This is one of the safe good option to try to eliminate humming unless it is because of some other reason.