Noise!! AARGH!

**sq_geek** · 09-09-2004, 10:13 PM

OK, so I finally did some more troubleshooting on my carpc to find out where the source of the noise is coming from.

The noise is basically like faint white noise which doesn't really change with RPMs, it's just static and annoying when music is low or not playing.

BTW, this noise occurs anytime the RCA is plugged in from the carpc to my amp. The noise comes from my speakers, obviously.

I found out that the cause of the noise is both my carpc's power cable (via an ITPS mind you) and also the VGA cable when the LCD is plugged in. Nothing even needs to be on (LCD/carpc), it just occurs when the engine is on.

So clearly the engine noise is coming in from +12v. But why is it going out through my amp and not somewhere else? Do I have a crappy ground somewhere?

My carpc is grounded to the same place my amp is, and it's a pretty good ground (4awg with a huge ring terminal and the ground point was filed/sanded to bare metal). I also tried adding a chassis ground to the carpc case, but no luck.

Or maybe my sound card needs to have an extra ground added? If so, where? I have the Audigy 2ZS. I should probably try the Via M10000 native audio out and see if they, too, exhibit this noise.

ANY IDEAS??

**Quattro** · 09-09-2004, 10:23 PM

I'm pretty sure its a problem with the ground somewhere, make sure everything is grounded properly.

Originally Posted by sq_geek

The noise is basically like faint white noise...

I never knew noise had colors, must have been smoking the good stuff when listening to the noise.

j/k

**sq_geek** · 09-09-2004, 10:31 PM

Ok, so let's assume it is a ground issue (I hope it is, cuz that means I'm close)...

Would the issue be the ground for the source of the noise (LCD or ITPS), the sound card/chassis or would it be the output device (Amplifier)?

**walky_talky20** · 09-09-2004, 10:48 PM

Just to define

White Noise - Acoustical or electrical noise of which the intensity is the same at all frequencies within a given band.

just a little different than

Pink Noise - random white noise that has been adjusted so there is equal energy per octave

which is used in the audo field for tuning and testing and what not.

carry on.

**johnnyutah36** · 09-10-2004, 12:15 AM

are u using the lilliput egg adaptor to power the lcd?

**aguila** · 09-10-2004, 01:00 AM

i am, why do you ask. can this cause the noise?

**sq_geek** · 09-10-2004, 10:02 AM

I am not.

**johnnyutah36** · 09-10-2004, 09:24 PM

Mine caused alot of noise. I could cup it in my hands and hear the noise go away. When I opened them up the noise came back. So I got rid of it and now power the lcd from the opus.

**MegatronUK** · 09-11-2004, 03:28 AM

I had the same problem when I was using my Xbox-Linux in car setup. I attached a seperate ground cable to the metal chassis of the Xbox and it went away.

If your carpc is not powered using a UK-style plug which has 3 wires including a seperate ground wire (i.e you have a power cord like the Xbox with only +ve and -ve) it's not getting a good enough earth. Put a grounding strap/cable from the chassis of the computer to the body of the car. Solved all my problems - no hum or interference.

**PaCMaYNE** · 09-11-2004, 03:48 AM

id idnt read all the replies,, not enough time... but ground your VGA shielding cable,, solder a piece on that *****,, then ground it,, itll do wonders,, just watch