Engine Noise????

I seem to be getting a lot of engine noise through my amp that powers the 6 speakers in the boat (Alpine MRV-F340). The noise does not seem to be present in the subs, or the tower speakers which each have their own amp. Anyone have suggestions for getting rid of the whine?

You Need to run all of the negative terminals of the amplifiers to the same place. If the are not you will pick up the altenator noise. I had the same problem and rewired all the amps and head unit to the same spot and the noise went away. The shorter the ground distance the better.

Now that you mention that, the amp with the noise is grounded to a different place. Thanks! I'll give that a try!