How do you stop a sub woofer humming when connected to a BTL amplifier (via the speaker terminals) and the speaker outputs are floating?
I know one way would be to use a RCA cable from my pre amp, and use the low level input, but this is not convenient, as the headphone amp is connected there.
I have tried leaving the ground floating, and I have also connected it to the chassis ground.
With the sub connected, low volume listening is more pleasurable, which is why I want to keep it connected.