Major crackling speakers, tried everything!
I recently just installed my car pc into my 1992 toyota celica. Everything works fine (except the bios, which keeps forgetting things - but that's a different story :)), but my sound does not. I'm running a 70w rms alpine amp for my 6x9's and another 1500w rms amp for my subs. Both amps are fine, they work brilliant from an ipod. However when I plug the rca from the amp to the 3.5m jack speaker output on the pc, it starts crackling. I can cut out the crackling by turning the gain right down on the amp, but then I can only have the music at a very low volume. The RCA lead isn't dogy, nor is the speaker output on the pc, as i've tested it with headphones. I've searched the forums constantly for the last few days looking for a solution, but i've yet to find one. How should ny PC be grounded in the car? I've even bought a usb soundcard, which I thought fixed the problem, but as soon as I plugged the usb cable in, crackling starts again, except alot louder!
Sorry for posting *ANOTHER* thread on speaker buzz, but this one really has me stumped!
ps, all the grounds in my car are decent, scraped away paint etc.
pps, My pc is housed in a custom built mdf case, would this need additional grounds?