My guess is that you are running RCA's thru your system...Usually a good idea is to chase the rabbit down, if you catch my drift. If you are running to amps, begin by removing your signal RCA's to your crossovers/amps and see if the noise leaves. If yes, then you have a bad deck. If no, then you go to the next component in your chain.
Check also to see if the noise filter is in good shape under the hood and see if it is clamped correctly. Also check your grounds all of them. Make sure that they are connectected to a substantial piece of metal and that the screws have not worked loose. Look for frays on your wires where they meet power and ground both on your deck and on your amps. Also, check your noise filters that you have installed. Some have a habit of making installers go nutz cause they go bad quickly or wear out. The biggest thing to do is chase your wires down and make sure that they are still in good working order.
Peace out
Rich
