4 channel amp engine 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=93705
Printed Date: May 02, 2024 at 4:00 AM
Topic: 4 channel amp engine noise
Posted By: benzdwn
Subject: 4 channel amp engine noise
Date Posted: May 07, 2007 at 11:57 PM
Hi I just re-did my audio system with all new products. I'm getting bad engine noise.I have a pioneer avic-d3 and a rockford p400.4 amp.With the infinity kappa 5x7.Installed in a 97 ford expedition I work at a chain install shop.I've been M.E.C.P. for less than a year.This problem I'm having is just kicking my butt. I ran new Rca's down the center of my truck.Got rid of little bit of the noise. My main issuse is: Static when the engine is off,Whine when the engine is on,and when i unplug one set of rca's I get tons of static/whine on the speakers that are still plugged in.I'm thinking bad main ground which would be ground loop? Also I get a very small poping sound when my brake lights go on? I know your all thinking I'm mecp i should be able to figure this out,on my own.I just cant. Thanks for your help in advance
Replies:
Posted By: haemphyst
Date Posted: May 08, 2007 at 12:03 AM
It's the Pioneer HU. If you unplug all of the RCAs, does the noise end completely?
Try plugging ANY other source, a walkman (or iPod... whatever) would be best, so it's completely isolated from the car's power supply. Use a "Y" adapter so all four inputs are used, don't let any float. Come back and post your results from that test.
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: benzdwn
Date Posted: May 08, 2007 at 12:22 AM
Thanks for your reply.I have heard that pioneer preouts suck before.when I unplug the rca's I still get the static/hissing sound.also when I plug in the i-pod with the y adpt I get a loud buzing sound
Posted By: benzdwn
Date Posted: May 08, 2007 at 12:30 AM
I forgot to add I tried grounding the rca's outter loop at the amp and i get even louder buzzing Thanks a lot for your help
Posted By: DYohn
Date Posted: May 08, 2007 at 12:39 AM
Sounds like a really bad ground on the amp. How is it grounded? ------------- Support the12volt.com
Posted By: soultinter
Date Posted: May 08, 2007 at 10:02 AM
You should have a test tone generator first and foremost when looking for probs
Posted By: haemphyst
Date Posted: May 08, 2007 at 5:33 PM
DYohn has hit on it, I think. If it's NOT the Pioneer, and you get buzzing on the amplifier alone, it is entirely possible that the ground traces inside the amplifier are bad. I'd check for continuity between the RCA input ground and chassis ground. IIRC, Fosbreak amps are isolated grounds, so you should read nothing. If you get a reading of any sort, it is a good chance that the amplifier needs repair.
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: benzdwn
Date Posted: May 13, 2007 at 11:27 PM
I found out I think its my rca's.I tried a different deck,the noise was still there.I unplugged the red rca from one pair and touched it to ground,thats when the noise went away.what could that be? Bad rca's picking up noise? I ran all rca's down the the center by the transmittion hump.I did remove the insulation from the rca's and grounded the shielding and it helps reduce the noise but its still there. Thanks Ryan
Posted By: DYohn
Date Posted: May 13, 2007 at 11:40 PM
benzdwn wrote:
I found out I think its my rca's.I tried a different deck,the noise was still there.I unplugged the red rca from one pair and touched it to ground,thats when the noise went away.what could that be? Bad rca's picking up noise? I ran all rca's down the the center by the transmittion hump.I did remove the insulation from the rca's and grounded the shielding and it helps reduce the noise but its still there.
If grounding the RCA shield helps that is generally an indication of a bad ground plane in the head unit or the amp or both. But sure, try different cables just to be sure. ------------- Support the12volt.com
Posted By: hamzter
Date Posted: July 16, 2007 at 8:37 AM
I have the same problem, but not sure if touching ground on the rear channel of my MTX amp will fix it.
I will try and work on it after my morning class.
benzdwn, did you fix you noise problem?
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Mark "Hamzter" Cinense
1991 Infiniti G20 w/JDM SR20DE
Eclipse CD8445
MTX Thunder 684
Polk DB6750
Polk DB6500
Optima Red Top in the Trunk
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