Kicker kxm800.5 preamp out

[BrettLee3232]

The internal traces on the HU RCA grounds are very fine. These internal traces are typically fused to prevent more serious damage to the HU. But the fused links aren't really serviceable. This link is often broken by connecting and disconnecting RCA cables (at either end) while the audio system is powered up = big mistake.
The scheme is to reference all audio grounds back to one location, the HU, in order to avoid ground loops. Generally all other amplifier and processor audio grounds are above ground and don't reference to true ground, other than through the HU. However, when this ground termination is interrupted, noise becomes a problem specific to that RCA set, whether front, rear, or sub/non-fading. To remedy you connect the exterior RCA shield ground to the HU chassis ground, which is true ground.

I guess a picture would help me understand lol


Sent from my iPhone using Tapatalk

[z28ke]

Here is a photo I found online.

[David Analog]

Here is a photo I found online.

Looking at that photo, it seems so improbable that someone would have to do such a bizarre thing as a fix for noise. Rarely it is required.

[BrettLee3232]

Is this similar to a ground loop isolator? I know everyone says GLI are temporary fixes but usually everyone says they work. I've noticed more and more I have more buzz when engine is off.


Sent from my iPhone using Tapatalk

[MLA]

Glad to see you isolated the noise and found the fix rather than use pass thru- RCA ports for a completely different zone, and 2, glad to see it fixed and not with the use of a GLI.

[David Analog]

Is this similar to a ground loop isolator? I know everyone says GLI are temporary fixes but usually everyone says they work. I've noticed more and more I have more buzz when engine is off.


Sent from my iPhone using Tapatalk

Nope. You could say this fix is the polar opposite of a GLI. Keep in mind that if you have continuity between the HU RCA ground shield and the HU chassis, as you should, then the fix shown in the photo is not needed. This fix is not a band-aid like a GLI (a GLI leaves the real problem intact), instead the fix shown is a correction for something that was broken, and restores the HU back to normal status.