Aftermarket Stereo Interference

[Wongy295]

Hi guys,

I recently had some aftermarket audio installed in my VF Wagon. 4 Speakers, 2 amps and a sub.

Unfortunately, I have some alternator noise coming through the speakers, as well as a buzzing when my headlights come on.

My audio installer is having a hard time working out what the cause is, and is leaning towards the fact that my amps are installed under either front seat, and the power cables for the car run down the middle. He's already tried moving the RCA's and it's made minimal difference.

I can't fiddle around with the gains too much, as turning them up will make it worse. Doubt it's an earthing issue, as the cables go directly back to the battery negative.

Has anyone had this issue or have after market audio with NO problems?

Cheers

 

[Timmah]

You said you doubt it's an earthing issue, but then said the cables go straight back to the battery. The ground cable should be as short as possible, not back to the battery...

 

[Wongy295]

Sorry for the late reply. I didn't realise anyone had commented.

The guy who installed the stereo just went straight back to the battery. I've moved house since then unfortunately.

Should I just go to the chassis? Could going to the negative cause the alternator noise?

Warm regards

 

[wraith]

Ground should be as close to the amp as possible.

 

[cewing]

Ground to chassis. If your main ground fails between your battery and chassis the current (hundreds of amps on startup) will try to go through your amp if it hooks up directly.
The worst thing is the car will still start, but your amp will probably fry.

As for the whining, there are literally 1000s of threads on that all over the internet.

 

[Timmah]

Should I just go to the chassis? Could going to the negative cause the alternator noise?

Yes it could. Without going to far into electrical theory, the longer the ground lead the more chance you'll have of getting whine. There probably wont be too many screws under the carpet, but you may find mounting points for the center console could work. I wouldn't advise using the seat or seatbelt mounts for safety reasons. I'm a little concerned about the qualifications of the person who installed it... For audio installers, grounding as close to the amp is one of the golden rules. If you're not keen on tackling it yourself, I'd go to a shop (there are a few good ones here in melbourne ) or get someone experienced to lend a hand

 

[GMHVF6]

Make sure if you have front splits fitted, They are moved away from all wiring on the front kick panels, I had this same issues on initial install, When i turned on headlights and even when i applied the brake i got interference, It was simply feeding back thought the system through the crossovers.

 

[Wongy295]

Thank you all so much!

Turns out the grounding at the battery was causing my issue. Pulled them back through the car, cleaned some paint and screwed the grounds to the chassis.

Problem solved!