You are experiencing what is commonly known as DC offset from the power supply of your amplifier. If I have read your situation correctly, you need to have the power supply section of your amplifier looked at perhaps. It is my wager that there is a resistor inside that allowing a small portion of DC to pass through and thus is not performing to the rating that the resistor manufacturer intended for it. When this happens, DC will be able to be sent to the speaker outputs.....you should be able to measure it! Give it a try. That is what it sounds like you are experiencing anyways.

Good luck

 

wow that was an excellent burn, but not entirely true, but yes their is still a little of the mobile dynamics somewere in the back of my brain, i try to forget as much of it as possible and use real life theory.

 

Couldn't an appropriately sized Capacitor in series block the DC? Make it a high pass for above something ridiculous like 30 Hz?

 

I am big on full grounds and powers from battery!!