I've recently installed an Acer EEE pc laptop into my dashboard, and everything is working perfectly, except I'm having the very common problem of engine noise..
I've looked through the various threads on here explaining how to isolate the noise, but I've hit a wall..
My car is a Fiat Stilo, currently set up like this:
Input voltage is the old headunit +12v, I've split that to go into the Amp and Laptop power inverter.
I have this inline noise supressor on the + of the cable between the laptop charger and the laptop. (This didn't help at all!!)
The laptop then has it's standard sound card line out connected to the amp.
The amp and laptop are ground to the same point. If I ground the amp, the noise gets louder. They're currently ground to the chassis, but I've also tried grounding them straight to the battery with no luck.
If I run the laptop on battery, the noise goes away. If I listen through headphones there's no noise either.
The next thing that I'm going to try is getting an external USB sound card.. Do you think that's the best way to go, or will I be wasting my time??
Thanks for anyone who can shed any light on this!!
If you want any more info about the setup just ask..
get a proper power supply for the laptop. interference in the power supply to the laptop is the source of your noise. any of the carnetix power supplies should do the job. and DO NOT power the amp off the the 12v line meant for your headunit. it needs to be at least a 8 or 6ga cable (depending on the power of the amp), fused, running directly from the battery and grounded to the chassis. the way you are set up right now is asking for all kinds of trouble like a short, or even worse: a fire.