I finished installing audio system throughout the whole car. When turn the car on there is a whining sound coming out from the speakers and not the sub. As I accelerate the sound gets louder. When I disconnect the RCA inputs to the amp the sound goes away. I don't know where the problem is. I'm running two amps both Kenwood KAC-5001PS and KAC-8406. My head unit is a Pioneer DEH-X6600BS. Any help is appreciated!

 

1. This belongs in the audio section.

2. You have the RCA ran too close to a power wire. If they have to be near each other make sure they are perpendicular.

 

Keeping power and line level wires separate is a good practice. A ground loop isolator will probably help a lot too, like this:

http://www.crutchfield.com/p_127SNI1/PAC-SNI-1.html?tp=61807&awkw=75640380625&awat=pla&awnw=g&awcr=476235 09025&awdv=m

 

Definitely in need of suppressor of some sort or a re-routing of your wiring, which sounds more likely.

 

I was thinking a possible bad ground as well.

Also, I just finished going through a similar ordeal. It turned out to be a faulty head unit in my case as I had checked and triple checked grounds, connections, and such. Once I got pioneer to replace the head unit, I reinstalled and no more whining.

 

i had the same issue. nissan doesnt use a ground in the harness. it's a crappy ground by the antenna. you need to run a line off the ground on the head unit make it as short as possible.

 

I did ground the head unit directly to a metal in front of the shift ****. I first sanded it down to get bare metal. The only thing that I remember is that the wire harness adapter came with two but I only used the larger one because I ran new speaker lines. Should I have ground the other adapter to ground?

 

I did run the power and signal lines separate the only spot that they are together is where the distributor block is and where the leftover RCA cables are at

 

You need a ground loop isolator.

I have one of these in mine and it took care of the problem.

http://www.ebay.com/itm/4-CHANNEL-RCA-GROUND-LOOP-ISOLATOR-REMOVE-NOISE-FILTER-/280594886057?pt=US_Car_Audio_Video_Interconnect_Cables&hash=item4154c22da9&vxp=mtr

 

that might be it, or another thing that can cause it is too long of a ground wire on an amp, should be less than 18 inches

 

I know people that ground to the front battery for their amps with no issues.

Copper has less resistance than steel so it's actually slightly better to run a 1/0 ground to the front than grounding to the frame/chassis

 

depends on who you ask, back when i was installing they said at least 8g and no longer than 18 inches

 

8 gauge? That's speaker wire man. I don't know anyone that uses something that small for power wire.

I just put a stereo in my buddies boat and we ran 2 runs of 1/0 from the batts to the amps (1 power 1 ground) and it doesn't have any problems with whines or other electrical noises.

 

also depends on the size of the amp....... and if you say it is speaker wire, than it is some thick *** speaker wire, about the same size as the barrel of a bic pen... and for power no, at least 4 g ... but i said ground

 

I know plenty of people that run 8 gauge for speaker wire. I have 10 gauge in my car but only because I had some laying around.

I know DD sells subs with 8 gauge direct leads.

Also, your ground wire should always be equal to or larger than your power wire.

 

Just in case you missed it, you have noise because you probably have a ground loop due to a potential difference between two ground points. You need to either ground everything to the same point or add a ground loop isolator. I added the isolator to my stereo and it took care of the issue. My symptoms were exactly the same as yours.

 

Another typical cause for engine noise is a speaker being grounded. Check and make sure your speaker leads are not touching parts of the door panel. If they're stock speakers then this is irrelevant.

Also, in my experience, Pioneer tends to have issues with engine noise due to their RCA outputs not having proper ground. Try grounding your RCAs (the negative shield) to the radio chassis.

Edit: I didn't see anyone mentioning the gains on the amplifier. If your gains are too high, there is a high risk of introducing unwanted noise, as well.

 

^^^This...

 

Well as wires go I have a 4 gauge power wire from battery to distributor block then to both amps. both amps are grounded separately. I also used 4 gauge on the ground side. I ran all new 12 gauge speaker wire to each speaker. I believe the problem lies either the grounding issue on the RCA's or I have my power and signal running next to each other. Can I place the ground loop isolator on the input side of the amp or it has to be on the output side of the head unit? This weekend I will be looking into it so I will tell you guys what I did to fix the problem.

 

It gets inserted between the head unit and the amp. Simple plug and play.