Engine noise from separate amp - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Electrical
User Name
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 07-03-2005, 07:10 PM
Last photo:
Join Date: Jun 2004
Location: TN
Posts: 484
Wiki Edits: 0

Thanks: 3
Thanked 7 Times in 7 Posts
Engine noise from separate amp

I have run low level RCA cables from the head unit to a separate amp in the trunk of my car for an extra set of rear speakers. The battery is also in the trunk, so I hooked the power and ground leads for the amp directly to the battery posts.

Everything works fine until the engine is running, then I get a loud whine from the speakers that changes with engine speed. The whine is there even when I disconnect the RCA leads going into the amp. So, it is coming in through the power or ground wire.

Do I need to avoid connecting directly to the battery, or is there a filter I need to put in the power lead, or on some other part of the electriical system?


Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 07-03-2005, 08:11 PM
docvette's Avatar
Registered User
Last wiki edit: Rebuild an alternator Last photo:
Join Date: Mar 2004
Location: Lafayette, california
Age: 64
Posts: 7,360
Wiki Edits: 12

Thanks: 0
Thanked 7 Times in 4 Posts

Doc here,

The engine speed whine you are experiencing is coming form your Alternator..

Get a Ferrite bear, or choke to install on your Alternator power wire, just a simple one loop thing through the bead..

You should be able to get one from radio shack, or an auto stereo store for a few bucks..

The other end of the equation is , by my best guess, your picking up RFI through your Speaker wire, and transducing that into "Noise" in the speakers.

Properly Gauge your COAXIAL <--READ speaker wires, and locate their harness as far away from power and ground harnesses as possible (like the other side of the car...)

Make SURE all your audio grounds are at the AMP end ONLY..NOT both ends..this will induce ground loops and hummimg.

Install ferrite beads on your speaker, power, and ground wires, or low pass filters to clean up all incidental noise.

Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 07-12-2005, 10:18 PM
Join Date: Sep 2004
Location: utah
Age: 33
Posts: 140
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
i have also had the same problem with one of my amps where the ground for the RCA's broke off on circuit board inside the amp.
Reply With Quote Quick reply to this message

Recent Electrical posts with photos

Quick Reply

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
ENGINE BALANCING NAIRB Engine 22 01-23-2016 01:44 PM
Rebuilt Engine Squeaking, Driving me Nuts! BH69Camaro Engine 24 04-22-2005 08:51 PM
New Engine Selection HotRodMan Engine 2 07-03-2004 10:22 AM
Too much engine? frankenvette Engine 39 05-18-2004 03:26 AM
Some questions about a Ford SHO Kaylah General Rodding Tech 11 02-21-2004 09:25 AM

All times are GMT -6. The time now is 12:16 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.