Nasty, Nasty PC Audio

**akwash79** · 05-08-2007, 05:42 AM

Where to begin?

I have a M10000 powered by the m1-atx psu. Both amp and pc are wired directly to the battery using 10awg wire and both grounded to the same spot under a bolt in the trunk(I DID sand this down to bare metal). The audio is going out directly to the 4-channel amplifier(no HU).

1st attempt - I used the onboard sound and got alternator whine and buzzing sound whenever the HD was being accessed or duriing mouse movements(on touchsscreen). When removing the RCA wires from the amp, the noise stopped.

2nd attempt - I used the Turtle Beach Roadie USB sound card for audio out. While this improved the sound quality greatly, the same alternator whine still persists. But...... get this......I no longer hear a buzz when the hd is being accessed or during mouse movements, the buzz is now constant and ONLY goes away when the hd is being accessed or the mouse is moved. WEIRD. I hooked up a pair of headphones to the audio out from the roadie and I did not hear any noticeable noise.

Also, my rca cables are no where near the power or ground wires.

My next steps:

1. Try hooking a cd player or ipod directly to the amps to see if the noise is still there(may be difficult to come across one of these without purchasing) I may try using my pocket pc, just need an adapter.

2. Ground loop isolaters - although this really doesn't SOLVE the problem just masks it.

3. Ground amp and pc under 2 different bolts?

4. Better RCA cables(although I really doubt that this is the problem)

Any other suggestions before I lose my mind?
99 Mercury Cougar

**akwash79** · 05-08-2007, 05:47 AM

Oh, I also tried muting everything even the 'Master' volume to no avail.

**DarquePervert** · 05-08-2007, 07:06 AM

Run the power wires as far away from the audio signal wires as possible. POwer up 0one side f the car, audio up the other side.

**durwood** · 05-08-2007, 07:30 AM

**akwash79** · 05-08-2007, 08:22 AM

no power wires near any audio wires except at amp connection of course

**RedGTiVR6** · 05-08-2007, 08:45 AM

what RCA cables are you using?

the walmart RCA cables or the like or actual quality RCA cables that you spent a little bit of money on?

**durwood** · 05-08-2007, 09:44 AM

I hooked up a pair of headphones to the audio out from the roadie and I did not hear any noticeable noise.

Might indicate a ground loop between your equipment. Other thing to watch out, keep your video cable away from your audio cables.

Might possibly be bad soundcard or chipset drivers but I don't think that is the case.

**Vodkapete** · 05-08-2007, 06:27 PM

Originally Posted by durwood

Other thing to watch out, keep your video cable away from your audio cables.

I've not heard this before - how come?

Ian

**RedGTiVR6** · 05-08-2007, 06:36 PM

same reason as power and signal and RCA and power, etc.

**symon_say** · 05-08-2007, 08:24 PM

It really doesnt matter if you put your power cable and your RCA together, the loop that the power cable creates is nothing to care about is you install your equipment propertly. Is more important to have good quality RCA than this.

I have a little audio store, and install a lot of systems with the cables in the same rail, and it doesnt create a loop, and have solved a lot of cases that they have noise and the problem were some bad conections, or bad ground in most of the cases, or maybe some equipment interfering each other, so try the options you post those solve the problem in most case or try to put as far as you cant you carpc and your amp.