Might be your cables bro.
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?
try grounding your motherboard and if you're still using your USB sound card, try grounding it.
Have you seen the stickey in here regarding trouble shooting these things?
Induced noise/Ground loop trouble shooting guide.
from the out on your motherboard to the amplifiers, do you have anything in between? like a head unit or a processor of any kind?
remember that on board audio only has around .5 v of output...which is not enough on it's own to provide decent sound.
Tried grounding the mobo, no luck. There is just a straight cable to the amp from the pc, i took the usb soundcard back. What would happen if i stripped the powercable to the pc and found the earth in that and grounded that? I'm in the uk so i'll be using british 3pin plugs.
thanks for the link to that sticky, didn't see it. from reading it through, i suspect that my pc is not grounded propperly, i'll try putting it in a metal case, and grounding that to see it the situation improves.
are you using an inverter? try just plugging in your psu to a wall socket, does the noise go away?
yeah, if i get an extension cable, the noise goes away. is it that the inverter is not grounded propperly then?
inverters are noisy by nature.
is there a reason you are using an inverter?
save your money and buy a DC-DC PSU and just go on with life.
i agree with red, save up for a dc-dc psu. i don't have any experience with inveters so i can't help you trouble shoot there. you'll have to research that one. but inverters are not only noisy but inefficient as well. you start with dc then the inverter switches it to ac then your psu switches back to dc.
I can't find any big dc-dc powersupplys. My pc needs atleast a 350w powersupply, as i'm running a 2.2 2800 athlon, sata raptor 36gb, 1gb ram and a radeon 9800 pro. Is there any good brands of inverters that are known not to cause noise?