I am hearing some engine whine in my door speakers? I believed it was a grounding problem so I reworked everthing this weekend. I ran 4ga wire from the battery to the frame, and moved the grounds to the amp to a spot closer to the amps. what else could it be, and what else can I do? It is really bothersome. running a jl audio 300/4 orion 1200d to diamond audio hex and a 12w7