I get a whirring noise going above 120 km/hr, only when I am accelerating. The amp is grounded to the chassis and the deck is grounded to some metal think near in the bay. The speaker wires are the stock, and I do get noise when putting the windows up or down.

Please tell me why.

I have a Pioneer DEHP2000 Deck, Pioneer X352 Amp under the front driver, Inifinity 652is in front and stock rears.