Noise only when Engine is running (Buzzing sound - increase with gain boost)

Originally Posted by bigaudiofanat

First off you're using too small of a power wire (10 gauge) to power your sub amp needs to be at least 8 gauge.

Second, your grounding location did you grind off the paint and expose bare metal? Have you tried a different grounding location?

The sound you're hearing is alternator wine. With those brand of amps their noise floor is very high so they re much more sensitive to dirty power. Yes I'm calling them cheap.

Where did you ground your head unit at? Any bare metal behind the head unit is okay just do not use the black wire in the factory adapter harness it doesn't go anywhere. This can cause noise.

Does the noise disappear when you unplug the RCA's from the head unit? If this is the case the noise is coming from the head unit and you need to work on it's ground. If it doesn't go away try unplugging the rca's from the amps. If the noise goes away move the rca's to the other side of the car. If you're using high input go to rca's

The difference between high level input and rca's you're letting the amp do the amplification where as high level the signal is already amped from the head unit and the amp has to filter it down to low level in order to use it.

Originally Posted by bangity

Regarding amp's location, I sanded down the bolt and the seat metal. I will try grounding it behind the kick plate today.

I don't have RCA yet but when I removed the high level input, there is no sound and the buzz disappears.

As for the HU, there is no specific ground cable. I used the harness. I also tried connecting the GND cable from the harness to the HU chassis but this has no effect. This is all using high level input.

I am aware of the need of grounding the HU if case using the RCA's. Yes, the amp is quite cheap. it was only $60.

Originally Posted by bigaudiofanat

That black cable in the head units harness should ONLY be going to a metal chassis somewhere behind the head unit not to the rca's.

Swap to RCA's

Originally Posted by bangity

So just to clarify, I cut the GND cable from the harness and ground it to the metal chassis? instead of it going into the factory harness?

I ordered some dual shielded RCA. In the mean time, I will try the cheap RCA's I have lying around.

Originally Posted by bigaudiofanat

Yep, nissan's don't have a factory ground the adapter harness you bought with the black wire is only for Subaru