HDD&Engine noise, only with the carpc

**Cris** · 03-28-2006, 05:25 PM

This is how I have my sound:

Carpc in the back --> quality RCA cable to aux input from the HU upfront --> quaility RCA cables to amp with sub in the back.

I have all power wires through the left side, signal wires on the right side, USB/VGA/AV through the middle. Ofcourse, they all meet up in the back...

All wires used are high quality wires.

I have a good grounding point, down to bare metal (one for both carpc and amp).

I tried to groung the case, no luck. Tried a ground loop isolator, still no luck. Also tried a USB soundcard, still no luck.

The HDD&Engine noise is present through ALL the speakers. It's also present without RCA leads or the VGA cables plugged in.
I'd also like to mention that with the Radio or CD, the noise is NOT present.

Also, the noise isn't that high in level, so the sound is good, but it shouldn't be there.

So, Red, and other Car Audio gurus, what else can I do?

**tj!2k4** · 03-28-2006, 05:33 PM

<ot>when did you get another car?</ot>

try grounding pc & amp to the same spot?

**Cris** · 03-28-2006, 06:02 PM

Originally Posted by tj!2k4

<ot>when did you get another car?</ot>

try grounding pc & amp to the same spot?

I got rid of the Megane a long time ago, and got a good deal on an Astra in the meantime. Still saving up for my dream car, the latest 5 series...

The PC has always been in the Escort.

They are both grouded in the same spot. I tried grounding them to different ponts but no luck.

**Cris** · 03-29-2006, 07:32 AM

**RedGTiVR6** · 03-29-2006, 07:41 AM

some HUs have an aux input level adjustment - if youre HU does, check that

also, try and ground EVERYTHING to the same point, HU/Computer/Amplifiers/etc

there's also the chance that the RCAs from the HU back to the amplifiers are carrying some noise. (another reason optical is preferred IMO)

let us know about these possibilities!

**Cris** · 03-29-2006, 08:02 AM

Originally Posted by Red GTi VR6

some HUs have an aux input level adjustment - if youre HU does, check that

No, it doesn't. It's a Panasonic CQ-7300N.

Originally Posted by Red GTi VR6

also, try and ground EVERYTHING to the same point, HU/Computer/Amplifiers/etc

Everything is connected to the same point...

Originally Posted by Red GTi VR6

there's also the chance that the RCAs from the HU back to the amplifiers are carrying some noise. (another reason optical is preferred IMO)

let us know about these possibilities!

I'm not sure, because the noise isn't present with the Radio or CD. I'm thinking more likely it's the RCA cable comming from the carpc to the aux input of the HU.
As I said, the noise is still there even without the RCA leads plugged in...

Also, the speaker cables have all been replaced by high quality cables...

**sama** · 03-29-2006, 08:14 AM

have you tried standing on your head?

do you mean the noise is still there without the RCA's plugged in to the carputer but still into the HU, or not into the HU at all?

**Cris** · 03-29-2006, 03:13 PM

Originally Posted by sama

have you tried standing on your head?

do you mean the noise is still there without the RCA's plugged in to the carputer but still into the HU, or not into the HU at all?

Yes the noise is still there without the RCA's plugged in to the carputer...
I can't get the RCAs out of the HU becuase I can't reach them...

I tried standing on my head, it just made it worse...

**sama** · 03-29-2006, 04:46 PM

I recon the long lead is picking up noise from somwehere else. perhaps there's a wire (fuel pump maybe) that's running parallel to the RCA cable somewhere.

you want to try to keep audio lines at least 8" away from power lines.