Subwoofer Grounding

[Neutron]

I have a subwoofer that every now and then makes a feedback noise (sounds like a fart). It's only when there's nothing going to it. It could be connected to my A/V receiver and make the noise when the receiver is off, and has done it when unplugged from the receiver.

Is there any way to ground it?

I have it connected to the receiver via a coax line, not speaker line.

 

[CochiseGuy]

I have a subwoofer that every now and then makes a feedback noise (sounds like a fart). It's only when there's nothing going to it. It could be connected to my A/V receiver and make the noise when the receiver is off, and has done it when unplugged from the receiver.

Is there any way to ground it?

I have it connected to the receiver via a coax line, not speaker line.

What type of power cord is it - the 3 prong connector, with the round ground prong at the top?

How do you have it plugged in - to an outlet on the wall, or to a power source on the receiver?

I have my sub woofer plugged into the power outlet on my receiver, so when I turn off my receiver it turns the sub woofer off as well. But, the power outlet on the receiver was only two prong, so I used on of those two prong adapters. When I moved to a new house a few years back I was getting radio station feedback through the woofer. Also, some popping noises when I turned the receiver off & on. On the advice of a friend, I used the little green cord on the two prong adapter to ground it to a screw on the receiver. That took care of all the problems for me.