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RCA Whine, Newly Installed Amp

I had infinity speakers in my car when I bought it, but the amp was taken out. I put an amp in yesterday and cannot get rid of a high pitched whine through the speakers only when the car is on. I also had typical alternator whine but found that be from a bad ground (it's fixed now). Here's the situation, if the cars on and running I have the whine. When I unplug the two rca's for the front speakers from the amp the whining goes away, same for when I unplug just the rear rca's. If three or more are plugged in the whining returns. Any suggestions on how to get rid of it because I haven't found any.

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Re: RCA Whine, Newly Installed Amp

The shield ground is probably open in the head unit. You can check the shield ground by measuring the resistance from the shield of the RCA connector to the chassis of the head unit. It should be near 0 ohms. Disconnect all RCA cables from the head unit before testing.

If you find that the shield ground is indeed open, the following link has more information for a temporary fix.
Temporary Shield Ground Repair

Posted on Nov 18, 2007

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Re: RCA Whine, Newly Installed Amp

Get some good rca cables.I had the same problem with cheap wiring. So I went out and bought high-end rca cables. They cost me 40 bucks but it stoped all my noise.

Posted on May 19, 2009

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Bought a hitron 3200b secondhand. installed the amp and no sound I have a 06 gmc I am using an aftermarket radio it is a lo line model made by I think dual 50 bucks at walmart all connections are good...

Bypass the amp with a small speaker or tweeter to make sure your rca input is working. Is the amp light on. Got good power, ground, and remote? Have you tried a different set of speakers on your amp?

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Another conundrum

To check for yourself, get an Ohmmeter and see if the outers of the amplifiers RCAs are connected to the ground or each other. If so then it cannot take speaker signals directly.
I suspect the 'High Level' the manual speaks of are the 4volt auxilliary audio signals that can be found on some newer head units, not speaker signals.
Speaker level signals from a bridge amp CAN be used on grounded RCA inputs if the signal is first passed through a simple decoupler and attenuator.
Diagram to explain....

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not usualy if you were running them before without the amp the speaker could have still easily blown. with just the deck running the speakers you can clip the sound and damage the coils hook up and amp then you force the power through an already damaged speaker finishing it off try another speaker. or if it was bought used amp may be no good the previous owner probably noticed it cutting in and out and sold it before it fried. or the deck is old and yes it is a possibility the radio went bad. if you used cheap rca cables yes it could be bad as well.

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Your stereo is picking up alternator whine. If you're good, you can make the motor fit with the song... kidding.
you can purchase a noise filter that will fit on the ground line of the alternator.... here's a few to scope out online

this will get it out for ya...

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Hi Justin,
Send me the specs. on the speaker ( voice coil impedance), amp, power wire size, and box
As for engine noise ( alternator whine) 99.9 times out of a hundred it's caused by what's called a ground loop, That will take a little trouble shooting on your part. It's no big deal. It will be a step by step process. All you need is two alligator clips or a old RCA cable.and a couple feet of wire. I'll try to get to it this evening,
Oh, and you will have to pull the head unit out of the dash... P

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1 Answer

High Pitch Whine from Amp (not speaker)

make sure your rca andpower/remote wires are ran on seperate side of your maybe recieving some kind of interference from the alternator. try buying higher shielded wiring too

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The easiest thing to test is to try swapping the connections of the front component speakers at the amp connections. If the problem follows the speakers, the issue is probably with the speakers. I would triple check (again) the speaker wire connections. It's also possible the crossover for the driver side component speakers has an issue (thus why the tweeter worked for a while).

If the problem stays on the drivers side, the issue is probably with that channel on the amp. Triple check the RCA connections for that channel.

It's much easier to test other speakers on an amp channel versus trying to check it with a meter.

If the driver's door is "abused" often, my initial thought is the wiring at the speaker or the wiring in the speaker (to voice coil, within the crossover, etc) is the most likely culprit.

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