buzz noise

sign man wrote:
so i removed the speaker making the noise & lo n behold it was the positive & negative clips touching the aluminum siding. so i bent them outta the way & presto, no more buzz.

Good deal but it also means something else--You have some sort of current in the trailer skin. If there is no signal being passed from the entertainment system, i.e. it is off, there is some current present that makes the speaker's coil vibrate/move. An unpowered speaker is quiet.

Try this: clip a meter lead to the trailer skin, set meter on small voltage scale and embed other meter lead in the ground. Do you see voltage? If so you have "hot skin effect" Google it for remedies.