Car Audio Discovery
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=59578
Printed Date: May 09, 2024 at 4:59 PM
Topic: Car Audio Discovery
Posted By: dirty651
Subject: Car Audio Discovery
Date Posted: July 17, 2005 at 1:32 AM
I've been dealing with alternator whine for a while. Today i found out that if you take a piece of speaker wire and ground your head-unit CHASIS to ANY of your rca plugs, alt. whine dissappears completely. I've read alot of post on this subject through-out the web and never read this as a solution. I've try'd everything everyone has ever suggested and it never worked. When i found out this solved the problem, i was amazed. If you still have alt. whine try this it might work for you too.:o):
Replies:
Posted By: DYohn
Date Posted: July 17, 2005 at 9:02 AM
This solution (grounding the outer ring of the RCA plug) is often suggested and will help with head units or amps that have poor quality internal ground planes. It is not always the solution for alternator whine, although it can help in some cases. ------------- Support the12volt.com
Posted By: Velocity Motors
Date Posted: July 17, 2005 at 10:24 AM
I would not consider this a solution, rather a band aid fix.
-------------
Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: dirty651
Date Posted: July 17, 2005 at 4:02 PM
DYohn] wrote:
his solution (grounding the outer ring of the RCA plug) is often suggested and will help with head units or amps that have poor quality internal ground planes. It is not always the solution for alternator whine, although it can help in some cases.
I grounded the outer ring of the rca plug, but that made it worse! I accidently grounded the rca to my HU CHASIS, NOT HU GND and alt. whine went away. I read all the stuff YOU suggested and it did'nt work. ALL i'm saying is this worked! DUDE!
Posted By: dirty651
Date Posted: July 17, 2005 at 4:06 PM
If this is a BAND-AID FIX, then everything people suggest to rid alt. whine is also a BAND-AID FIX! Dont get me wrong, I did Big 3/4, gnd hu to same amp gnd plane,ran power and rca seperate...etc...
Posted By: DYohn
Date Posted: July 17, 2005 at 6:13 PM
Sounds like your HU is defective or very very cheaply made. Glad it worked for you. Cheers. ------------- Support the12volt.com
Posted By: Velocity Motors
Date Posted: July 17, 2005 at 10:33 PM
Some vehicles are inherent to ground noise no matter what you do. Chevy trucks are infamous for this.
-------------
Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: kgerry
Date Posted: July 18, 2005 at 11:37 AM
dirty651.... the "solution" you came up with should be looked at from a diagnostic point of view only..... by grounding the shield of the RCA cable and the noise going away, you simply confirmed that you likely have an open ground in the audio pre-out section of the head unit.... a proper fix would be to take the HU apart and repair the open ground foils, not leave the wire connected to the RCA's....the pre-out section audio ground paths are usually filtered and buffered with SM isolation caps which you have now bypassed.... kudos on being able to track down the problem yourself!! but keep in mind the reason you dont see this given as a fix to try is that it isnt really a fix... it's a backyard barney DIY fix.... i think most advice you would get about this is to diagnose where the problem lies (which you have done) and then from there have the actual problem corrected..... ------------- Kevin Gerry
Certified Electronics Technician
MECP First Class Installer
Owner/Installer
Classic Car Audio
since 1979
Posted By: JAydawg21
Date Posted: July 18, 2005 at 11:45 AM
Velocity Motors wrote:
Some vehicles are inherent to ground noise no matter what you do. Chevy trucks are infamous for this.
Happen to know if Jeep Cherokee's have the same affliction?? I've tried a few things and haven't come up with a solution as of yet. All external grounds are good and wiring runs are seperated. ------------- '97 Jeep Cherokee sport
subs: JL 12w3v2 : RF 500a2 :
RF 1F capacitor
doors: 6" Diamond D361i -> RF 200a4
Posted By: Drewt
Date Posted: July 18, 2005 at 12:16 PM
the ground from the chassis to the battery in cherokees is horrible. have you upgraded that??
-Drew
Posted By: JAydawg21
Date Posted: July 18, 2005 at 12:37 PM
NO, But thanks for the tip! I will def. look into that. What is bad about it?? Is it the conductor itself or the location or corosion problems...?? ------------- '97 Jeep Cherokee sport
subs: JL 12w3v2 : RF 500a2 :
RF 1F capacitor
doors: 6" Diamond D361i -> RF 200a4
Posted By: dirty651
Date Posted: July 18, 2005 at 1:11 PM
kgerry wrote:
dirty651.... the "solution" you came up with should be looked at from a diagnostic point of view only..... by grounding the shield of the RCA cable and the noise going away, you simply confirmed that you likely have an open ground in the audio pre-out section of the head unit.... a proper fix would be to take the HU apart and repair the open ground foils, not leave the wire connected to the RCA's....the pre-out section audio ground paths are usually filtered and buffered with SM isolation caps which you have now bypassed.... kudos on being able to track down the problem yourself!! but keep in mind the reason you dont see this given as a fix to try is that it isnt really a fix... it's a backyard barney DIY fix.... i think most advice you would get about this is to diagnose where the problem lies (which you have done) and then from there have the actual problem corrected.....
No matter what, I think i'm SOL, because i have a pioneer premier deh-p860mp, I read somewhere pioneers have poor floating gnd planes in there hu's. I've try'd everything with no luck, so this is my fix.
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