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Noise Problem, Yet Another!

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=40718
Printed Date: July 12, 2025 at 7:41 PM


Topic: Noise Problem, Yet Another!

Posted By: jackchoo
Subject: Noise Problem, Yet Another!
Date Posted: October 11, 2004 at 10:59 PM

Hi,

My previous configuration ran fine. It was there when I got the car (200SX Nissan S13). I was running RCA cable from the front LR outputs from my Pioneer headunit to the boot where my Rodek amps is. The Rodek amp powers the sub but it also provides a RCA loopthrough my other amp (JBL) that powers the front L-R speakers. This was running fine.

Until of course, I decided that since the headunit has a RCA read L-R/sub output, I wanted to have the headunit front L-R RCA to the JBL and the rear LR/sub RCA to the sub so that I can control the HPF available in the headunit without cutting out the bass to my subs.

Sad to say after I did this, I noticed that I cannot increase the gain on my sub amp too much as before because I noticed that the sub itself was vibrating up down pretty high and low! So I put the gain really low. I thought everything was fine but when I started the car, i hear very loud while coming from my front LR speakers.

I can still hear it with the headunit volume turned all the way down! apparently it has no effect on the while at all. So I reconfigured everything back to the way IT WAS when I first bought it and the whine is STILL THERE!

Funny thing is the whine goes away if I completly disconnect my sub amp power supply.

Got so frustrated that I removed my subwoofer (amp's still in the car) and totally disconnected the supply to the sub amp. Now I am running direct from headunit front L-R to the JBL amp. No subs. Whining is very very faint now but still noticeable when there is not much traffic noise.....

Beats the hell out of me figuring this out....can anyone suggest something to help out??

Thanks!





Replies:

Posted By: Rushman
Date Posted: October 11, 2004 at 11:39 PM

3 things..........Run better shielded RCAs , they may help block out the noise your picking up.  2nd........Be sure to run the RCAs down the oppisite side of the car of the power supply to the amp. Keep those two as far apart as possable.  3rd........if you dont or cant run better and more expensive RCAs , then go buy a Ground loop Isolator and install it inline to the JL amp. The Isolator is usually for me a last ditch effort to get rid of that pesky altenator whine. Thier about $15 - $20



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99 F-one fitty
Pioneer Premier H/U
Alpine EQ
Kicker 1200 amp
4 Kicker comp 10s
6 kicker SS65.2 components




Posted By: fatgotti
Date Posted: October 12, 2004 at 3:08 PM
Also if you have not already tried this cut your amp wire to no more than 2 1/2ft and reground it.  Also check to see if when you connected it that some how you crossed your RCA 's with a high voltage wire in your dash somewhere. Cheap RCA's if thats what you have love to find noise.

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Fatgotti    Yeah my name is John and I am FAT!! YEAH BABY




Posted By: audifive
Date Posted: October 12, 2004 at 3:19 PM

i agree, also make sure both amps are grounded in the same spot






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