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Alternator Noise in Speakers by bomluuk
Started on: 09-11-2014 12:15 PM
Replies: 6 (171 views)
Last post by: theogre on 09-15-2014 12:40 PM
bomluuk
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Report this Post09-11-2014 12:15 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
As stated in the title, I'm getting a bad alternator whine in my speakers. It got louder after my 3800 swap, to the point that it now bothers me.

I suspect its my ground. Its grounded to a seat mount bolt.
My power wire is run through a hole I drilled that runs behind the ecm.
My RCA cables are run through the center by the shifter.

Anybody care to weigh in on where the problem most likely is?
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Report this Post09-11-2014 12:19 PM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
Its usually from sound wires too close to power wires.
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Blacktree
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Report this Post09-11-2014 12:28 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
It could be ground loop interference. Try running a separate ground wire from the receiver to the amp(s), if you haven't already. Also, make sure the receiver and amp(s) all have good grounds to the chassis. And finally, the amp(s) chassis needs to be electrically isolated from the car's chassis. That means using rubber grommets or something else that's non-conductive between the amp(s) and the car chassis.

If that doesn't fix it, there are several brands / sizes of alternator noise filters available. For example: http://www.crutchfield.com/...h/noise_filters.html

The noise filters should be used as a last resort. They shouldn't be used as a band-aid fix for bad grounding, or whatever.

Best of luck!
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Alex.07.86GT
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Report this Post09-11-2014 01:54 PM Click Here to See the Profile for Alex.07.86GTSend a Private Message to Alex.07.86GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Blacktree:

It could be ground loop interference. Try running a separate ground wire from the receiver to the amp(s), if you haven't already. Also, make sure the receiver and amp(s) all have good grounds to the chassis. And finally, the amp(s) chassis needs to be electrically isolated from the car's chassis. That means using rubber grommets or something else that's non-conductive between the amp(s) and the car chassis.

If that doesn't fix it, there are several brands / sizes of alternator noise filters available. For example: http://www.crutchfield.com/...h/noise_filters.html
The noise filters should be used as a last resort. They shouldn't be used as a band-aid fix for bad grounding, or whatever.
Best of luck!


I dont think its possible to isolate your grounds when you only have 1 battery!! Unless you have a device to do this with.

The noise filters should be used as a standard and your grounds should be #1 on your priority/important list!!

I go to the 12volt.com

All About Grounds

[This message has been edited by Alex.07.86GT (edited 09-11-2014).]

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Report this Post09-11-2014 03:05 PM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
Found this

http://www.caraudiohelp.com...troubleshooting.html


Proper Grounding
Most non-equipment related problems in car audio are the result of poorly chosen ground points. Always check the integrity of every connection including the battery, head unit, amplifiers and signal processors. Any part of the audio system can bring noise into the system. In general your connections need to be secure (grounds should be to the chassis), the charging system should be in top condition and all factory connections (battery posts, ground strap, alternator connections) should be secure. You may need to increase the size of your factory ground if you install a very large stereo system. It should also be noted that the negative battery post is usually a terrible place to ground car audio equipment. All of the ripple (noise) from the alternator and other items in the vehicle travel to this point. If you choose it as a ground point then you are inviting all of these elements into your sound system.

Alternator Whine
Alternator whine is the granddaddy of car stereo noise. The most common and the most annoying. Alternator whine will be heard as a high pitched whine that will rise and fall with the engine speed. Most of the time this is caused by a poorly chosen ground for a piece of equipment. It is usually cured by grounding the equipment directly to bare metal on the chassis rather than an available factory ground bolt as is often used to save time. You'll also need to make sure your charging system is in top condition and that your connections between the battery and components are secure as well as the integrity of the factory ground strap, an often overlooked component. You might also consider switching your RCA cables to a twisted pair model. Twisted pair cables will usually be less prone to noise than their coaxial counterparts.

Accessory Pop
Accessory pop is associated with one particular electrical event in the vehicle. This can be switching on your turn signal, headlights, brakes, windshield wipers or even the rear window defrost. These high current drawing accessories are causing a voltage spike that is traveling into your car audio equipment with the result being heard as a sharp pop. Adding a small bi-polar capacitor (0.47 uF) between the accessory's power wire and ground will often absorb these surges. You may need to place the capacitor on the load or the power side of the switch (maybe both). See the diagram below to see how this is done. Note that the diagram is slightly different if the accessory has a relay in the circuit.
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bomluuk
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Report this Post09-15-2014 12:06 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
Moved my ground and still have alternator noise. I'll try the other methods and see if I can fix it.
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theogre
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Report this Post09-15-2014 12:40 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
OE sound likely has bad cap(s) at power input. Old caps will "dry out" and stop working to reduce E-noise.

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