Sgt wrote:You are hearing the alternator.
One thing you should do with your deck and amp, is check your power and ground wires.
I am not too sure what you can do to eliminate this. A voltage stabilizer may help, as would a capacitor for your amp.
This is not going to cause any issues, it is just annoying.
This.
Also, check behind your radio (if you have an aftermarket deck) to see if they installed a "Bose conversion" box thing. That's what was causing that issue for me. It was basically bypassing the ground for some unbeknown reason to me.