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weird noise

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=83754
Printed Date: May 08, 2025 at 9:47 PM


Topic: weird noise

Posted By: kingerik68
Subject: weird noise
Date Posted: October 05, 2006 at 7:23 PM

I have a 1998 Jeep Cherokee Classic. I just recently got a new system installed and am now having some kinda of horrible noise. I have 2 Audiobahn AWC12T subs wired to an Audiobahn A8002V and capacitator and 2 sets of Audiobahn ABC525T component speakers wired to an Audiobahn A6004T. The noise sounds like a high pitched whistle or something. When I turn my system all the way up it seems to go away, but when I turn or break, it comes back. It's also quite loud even when the sound on my cd player is on 00. I recently blew subs and was left with only my components for about 3 weeks and I didn't have this problem. SO basically it didnt start happening until I hooked them up to an amp. Anybody have any idea what could be causing this noise?



Replies:

Posted By: tcss
Date Posted: October 05, 2006 at 8:21 PM
Does it change pitch when you get on and off the gas?

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There is no such thing as free installation!




Posted By: kingerik68
Date Posted: October 05, 2006 at 8:28 PM
Yes...but now my components have completely gone out...LOL.... :-(((




Posted By: mike12volt
Date Posted: October 09, 2006 at 9:20 PM
Try to bi-pass your amp and hook up your components directly to HU.




Posted By: kingerik68
Date Posted: October 09, 2006 at 9:54 PM

so this will stop the amp from powering my speakers or no? cuz they sound doodiety without an amp powering them





Posted By: adrian314
Date Posted: October 09, 2006 at 10:39 PM
What kind of rca's do you have? Are they close to your power wires? You may be getting a ground loop. Start off with this topic. https://www.the12volt.com/installbay/forum_posts.asp?tid=37762&tpn=1




Posted By: master5
Date Posted: October 11, 2006 at 1:05 AM
You are experiencing the dreaded "alternator whine". Most often caused by whats known as a ground loop. I don't feel like explaining what that is in detail but a basic definition is more than one audio component with more then zero resistance to ground with each other. Don't worry if you don't understand it but basically it is ground related, although a bad battery and/or battery cable have also been know to cause this noise in some cases. The reason it "goes away" when you crank the volume is because the noise level stays the same but the music is louder, simply covering it up. You state something about it coming back when you turn or brake, and that it started when you hooked up an amp. First thing to do is Check the ground. This does not mean to just look at it, although if you do and can see it is loose or corroded fix that. If it looks ok you need a meter and make sure its good. Put the meter on resistance and touch one probe to ground, directly where it connects to the amp. put the other probe to some clean metal on the car, you want the resistance to be as close to zero as possible, if its an ohm or more reground it and see if the noise is gone. The other possibility is a bad RCA or loose connection on the RCA's. Jiggle around with all the RCA connections starting at the amp and with the volume low see if the noise comes and goes. Step 3 is to plug in a ground loop isolator. If the noise goes away and the sound quality is unaffected you have a fix, a band-aid yes, but the noise is gone. If that fails take a thin wire, ground it and touch it to the outer shield of the RCA's. If the noise goes away you have found the ground loop. Find a way to permenently ground the shield. I usually do this behind the head unit, carefully peel back the layer of insulation to expose the shield. Cut too far and you ruined the cable. Wrap the wire around the shield and ground the other end. reinstall the deck and happy noisefree motoring. If none of this works I would start substituting components to find the culprit. Try connecting a new RCA without hiding it to see if that helps. swap the amp, or deck until you track it down. Think of yourself as a noise detective except you are looking for something you can't see, not always easy, most shops won't even deal with a noise issue, even if they did the install. But do as I say and I bet you will find it. good Luck

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