whistling speakers,

[higgo_]

Hellow all,
could somone tell me how to stop the whistling in the speakers after you install an amp.

[Stav]

I ll have to charge you!! :

[Stav]

You have bad earths mate or you have poor quality equipment.

[Kraziman]

This might help. Found it at http://www.caraudiohelp.com

Car Audio Noise
The biggest offender of noise in the car audio environment is alternator whine. Alternator whine is caused by a difference in electrical potential (voltage) between two points. It's usually caused by a ground connection that is less than ideal. The main culprits are the amp, the head unit and any intermediate components such as crossovers and equalizers. Basically any component that touches the low level music signal (from RCA cables). It's usually cured by finding the source of the noise entrance and re-grounding that component.

Troubleshooting Car Audio Noise
You can usually isolate the head unit as the problem by disconnecting the RCA cables from the amplifier and inserting a muting plug (RCA plug with the connectors shorted together). This also eliminates any noise from components upstream of the amplifier such as crossovers and equalizers. If the noise is gone then you need to check the other components upstream of the amp. First, connect the head unit directly to the amplifier (assuming you have crossovers or equalizers between the two). If the noise is gone then your problem is the intermediate components. If the noise returns then it is a head unit problem.

In almost every case you will simply need to find a better ground location for that component. Clean, bare chassis metal is the best solution. Many times installers will use whatever factory bolt is handy and that can work and it can cause problems. Factory bolts are not a bad source necessarily, but if they have other electrical components using them as a ground this can be a source of noise. If you're not using a new ground point then you'll want to make sure your factory bolt meets the criteria above.

The next step isn't as much fun but it's needed to know for sure. Remove the deck from its mounting location and place it on top of the amplifier. Put a non-conductive barrier between the two (T-shirt is fine). Hook up the deck's power leads to the amplifier's power terminals. Then connect the deck to the amp with very short RCA cables. Male to male RCA gender changers are about the right length. If there is still noise then it's a very rare deck problem. Most likely it's coming in on the cables. A switch to unshielded, twisted pair RCA cables should usually cure that.

For more info (Engineer level detail) try this website
http://www.diysubwoofers.org/project...f/alternat.htm

Go to google and search for "car stereo alternator whine". That's what I did.

Good luck!