Aftermarket amplifier "whine"
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,011
Likes: 1
From: Marietta Pa
St. Jude Donor '10-'11-'12-'13-'14
Aftermarket amplifier "whine"
After re-doing my soundsystem, my speakers emit a "whine" that seems to vary with engine speed. I have the seperate subwoofer amplifier power wire running behind the distributor (1990 L98) but the speaker amp that emits the whine has the power wire from the battery straight back.
It also gets feedback from the 10-disk CD changer... while the car is on or off.
Is the amp shot? Or could it be a ground/power/interference problem? Any help would be appreciated.
It also gets feedback from the 10-disk CD changer... while the car is on or off.
Is the amp shot? Or could it be a ground/power/interference problem? Any help would be appreciated.
Le Mans Master
Joined: Jun 2004
Posts: 9,289
Likes: 16
From: Skippack PA
St Jude Donor '13
After re-doing my soundsystem, my speakers emit a "whine" that seems to vary with engine speed. I have the seperate subwoofer amplifier power wire running behind the distributor (1990 L98) but the speaker amp that emits the whine has the power wire from the battery straight back.
It also gets feedback from the 10-disk CD changer... while the car is on or off.
Is the amp shot? Or could it be a ground/power/interference problem? Any help would be appreciated.
It also gets feedback from the 10-disk CD changer... while the car is on or off.
Is the amp shot? Or could it be a ground/power/interference problem? Any help would be appreciated.
Melting Slicks
Joined: Dec 2004
Posts: 2,394
Likes: 0
From: Bay Area CA
It can cause issues yes. I rank it below making sure you 1st have a good solid ground connection with proper gauge wire to begin with, followed by making sure that your signal wires (rca's mainly) are not being crossed or closely paralleled by your power wires. Hell I ran into a tiny bit of whine in my own car and had to move an RCA (quality piece) approximately 3" to get rid of it 
Good solid ground connection meaning bare metal and tight to the frame, or back to the battery if you so choose. Loops can originate from the HU, but is more common with lower grade HU's that the "name brand" models.
G'luck
Fej
Good solid ground connection meaning bare metal and tight to the frame, or back to the battery if you so choose. Loops can originate from the HU, but is more common with lower grade HU's that the "name brand" models.
G'luck
Fej
Le Mans Master
Joined: Jun 2004
Posts: 9,289
Likes: 16
From: Skippack PA
St Jude Donor '13
Always start with the simple, so the first thing to do is use a common ground. This solves the vast majority of ground loop problems. On the assumption you have a solid ground for your amp (also as fej describes) then the best thing to do is to move the head unit's ground to the amp's ground point. On my C6 I have the factory head with an aftermarket amp and this resulted in a ground loop. I identified the ground wire in the radio's wiring harness using the service manual, clipped it and butt-connected a new wire on the side leading out of the radio, running it to my ground point for my amp. Problem was gone.
