the 'famous' static noise

[jroot]

Hi, I'm new to the board, it looks like there is a lot of people here who know there stuff, so I figure I'll post a problem I've been having (yes, I've done some searches as well)....

I'll start by naming my system components..

Head Unit - Alpine 9815

Amp - US Acoustics USB-4085

Infinity Basslink

Speakers - Infinity Kappas around (2 5 1/4's, 2 6x9's, 2 3 1/2's)

So my problem is if I have my engine running I get a static noise through my speakers which are hooked up to my amp. I won't get this noise if I don't start my car (Volvo 850). So I only get the noise when the engine is on and also when I turn off my car but not completly, the static will get more severe.

I have my amp + basslink grounded in the same spot. Power + Remote wires running on drivers side, and all other wires on the other side. I don't think anything is wrong with my audio wires at all. I'm using 8 gauge power and ground for both amp and basslink, 14 gauge or 12 gauge for my speakers.

I've tried just about everything I can think of to fix it, switching ground points, just lying the rcas over the seats, trying a different head unit (i haven't tried a different amp, so it may be the amp?), and numerous other things...

Someone told me that the static noise is coming in from the power line, and I need to get 4 gauge but I think 8 gauge is good enough, but maybe i'm wrong??

Also crutchfield gave me a suggestion to run my ground from the HU back to the amp location ground to eliminate the 'ground loop'.

So anyone have any other suggestions?

I even checked my ground which I think works in theory by hooking up jump starter cables to a good grounded car to my car thinking maybe my car didn't have the best ground but the static still remained there.

Thanks,

Jay

Click to read more...

 

[Shugarra 10+ year member]

Some threads:

http://www.caraudio.com/vb/showthread.php?t=45926

http://www.carsound.com/UBB/ultimatebb.php?ubb=get_topic;f=2;t=003807

http://www.carsound.com/columns/navone/nav0005.shtml

Alt wine = the devil. I sure hope yours is something easy! By the way, it's not going to be your power wire size, if you are running your rcas by the power, however, that is probably the problem. Good luck!

 

[helotaxi 5,000+ posts]

Are you using the factory radio ground wire? If so, this is likely your problem. Find a good solid chassis part behind the dash and move the ground of your HU there. Another thing to try is to get power for your HU from a wire direct from the battery. Fuse this wire of course.

 

[helotaxi 5,000+ posts]

Shugarra,

Where are you in MT? I live in Great Falls when I'm not deployed, as now.

 

[jroot]

Hey,

I have tried grounding the wire in other ways beside the stock radio ground...

What would the power from the direct battery do for me exactly, that the other power lead is not doing?

Also, do you think it's a good idea to run ground back to the amp ground location? -- I may try this..

I may also try ground loop isolators -- but not sure how much this will sacrifice my system?

Thanks,

Jay

 

[helotaxi 5,000+ posts]

What would the power from the direct battery do for me exactly, that the other power lead is not doing?

Sometimes the power coming off the main fuse block is a bit noisy. Taking it out of the equation can fix your problem. Try removing the deck and connecting it directly to the battery with as short a power wire as you can and check for noise. If the noise is gone, then the direct battery connection may be what you need. When you route the wire try to avoid any high current wire (alternator especially).

 

[Shugarra 10+ year member]

I'm in Bozeman =)

 

[maylar 10+ year member]

It's your amp. My USX-4065 also makes alternator whine. They're very sensitive to ground loops.

If the HU in your car is grounded to the dash (metal to metal), rerouting the HU ground wire won't do diddly. BTDT.

Ground isolators may be your only choice.

 

[jroot]

I had a feeling it was my amp...

Today, I tried hooking direct power to the HU, didn't help.

I also tried head unit with direct power and grounded to the same spot as the amp...didn't help.

This leaves me to believe a) My amp is crapped or b) I need ground isolators :-/

Any suggestions?

The amp might be able to be replaced since I bought it from crutchfield less than a year ago...

Thanks,

Jay