Car stereo really loud noise over bumps not whining

[VR_meanz]

Hey there guys was just wondering if anyone could help me out. Ive just put a new stereo in my car two amps, sub and splits front and rear. Is fine when standing still but when going over bumps car speakers are making a really loud feeback noise like its goin to blow the speakers. I took the head unit out and made sure no wires are touching then turned it on and noise still there. Its not a whining noise from car revs so not sure what it could be. Any ideas what it could be at all im pretty new with car stereos so has got me puzzled. Thankyou

[acarmody]

I'd carefully check all wiring in the stereo. If all the speakers feedback at exactly the same time, I would check the main power/ground cables.

[danja]

If you amp has a metal chassis, check the screws aren't shorting against the car body when you go over bumps. I once screwed an amp to the boot liner and it was shorting over bumps because the pointy end of the screws was sticking through the bottom of the liner and shorting against the body of the car.

[VR_meanz]

Cheers for the input guys. I have checked the ground cables and its definitely not shorting out on the body. Im thinkin its got somethin to do with the rca's because when i play with them on the back of the head unit the noise starts. The headunit only has one set of rca's so ive used 2 Y splitter cables so can use two amps would this cause any problems? Thankyou

[acarmody]

Test one amp without splitters and see if its good. Maybe the splitters are buggered.