I have Boston Component speakers up front (2006 Coupe) for almost 2 years now. Recently the driver front speaker only, randomly cuts out and makes a hissing noise with the engine rev, like a bad ground. As soon as I press the power door lock button, it stops and works fine for a few minutes. I've taken the panel off and checked for exposed wires, but nothing that I've found. Is it a ground wire? if so, at the amp, or does the speaker have its own ground??

Anyone with advice, thanks in advance.