I have Paradigm speakers powered by a Denon AVR-2805 receiver.
The sub has an auto shutoff if no signal is received from the receiver.

Just recently the sub will not shut off. When the receiver is OFF the sub
continues to emit a deep thumping sound. The power light on the front
of the sub stays on.

When I unplug the monster cable from the receiver to the sub it shuts down like it is supposed to and the light goes off. The minute I plug the cable back in to the sub it starts up again.

I have tried changing cables and it does the same thing.

Does anyone have any advice?