RM6750 sub random humming issues

[tyypo]

I just bought the RM6750 speaker set and the sub is humming. When the receiver is off the sub will hum for 5 to 10 seconds then stop. About a minute later it will hum again for 5 to 10 seconds again. This goes on and on. I've tried two different cables to no avail. Any ideas?

Thanks
:)


Yamaha RX-V661
12' RCA cable from receiver to the sub

[obieone]

Welcome to the forum
Try plugging the sub's power chord into the receiver's aux. power outlets(IF it has any)
I had a sort of similar problem with my sub-it would make a popping noise when I shut off the ceiling fan, even though the rcvr was off.
It was on its own outlet, seperate from the rest off the system, which was powered thru a surge protector.
I've sinced moved it to the rcvr's aux. outlets and it just makes a slightly muffled
noise now when I power down the rcvr.
Good luck