the system in my car came with it when i bought it, and every once in a while if i hit a bump or sumthin the amps start whining real loud, and then every time the rpms go up, the whining gets louder and higher pitched. what could this be and how would i fix it?

 

It's called alternator whine and it's caused by a ground loop and as the links below suggest, you need to find out where everything is grounded and perhaps rework the grounding points. Idealy you want to have your head unit and any controller units grounded to the same point and preferrably under the dash. Also your amps need to be grounded to their own 'common' ground. Last but not least and almost always forgotten, is check to see where the 'turn-on' (+) lead of the head unit is attached. Typcially some shmoe will attach it to the battery wire under the dash instead of the factory wire, to run the stereo with the car off. This is the worst possible place to attach it as the battery is hooked up directly to the alternator.

You may notice the whine may get worse once you reground everything. This means you need to pick another spot. The shorter the ground cables, the better.

http://www.caraudiohelp.com/newslett...ator_whine.htm

and

http://www.bcae1.com/audiots.htm - halfway down the page.

 

thanks, when i hit the seat it goes away, so i think its the ground for the amp