RCA cable noise

[rrmccabe 10+ year member]

I just did an install in a 06 Trailblazer. This system is a Pioneer Z2 connected to a JL Audio 5 channel (500-5) amp with JL Audio speakers.

I connected the amp with Monster cable RCA cables. These here

I am getting noise in the speakers that I can hear with low or no audio from headunit. I can unplug RCAs from the amp and it quits. It sounds computer generated to me.

My power runs along drivers side to amp in rear and pre-amp and backup camera run along sill plate on passenger side. There is a OEM loom on both sides under the sill plates.

I can access the RCA cable from the glove box and can introduce noise just by grabbing the cable.

Any ideas how to get rid of this. I assumed the monster cable should be decent. The head unit is well grounded as is the amp.

Thanks in advance.

Rich

Click to read more...

 

[mile098 10+ year member]

search for engine whine...congrats, u have the most annoying problem in car audio, and the hardest one to solve...i have it too, after tearing my whole car apart three times looking for a faulty spot in my install i tried another amp and it works fine...so my brand new amp is going to the shop some time this week...

 

[rrmccabe 10+ year member]

OK will search. Its really not engine whine. It does it with the truck not running !

 

[mile098 10+ year member]

ohhh, then i must have misunderstood u....then u have a faulty cable or an rca touching/passing near to a power cable, maybe a factory one or smthg....

 

[rrmccabe 10+ year member]

Yea sounds like computer noise to me. Something "synthetic".

It is running along a factory loom which might be the factory Bose amp which I am still using for Onstar.

I see that Pioneer has ground loop issues from reading post here. I might try grounding the RCA at the head unit.

 

[mile098 10+ year member]

one other thing pioneer has trouble with are the smd fuses inside the HU itself....they 'draw current' pretty easy and fry out if u forget to disconnect the rca's from the amps and mess around with the power wires...try another HU and see what happens

 

[rrmccabe 10+ year member]

one other thing pioneer has trouble with are the smd fuses inside the HU itself....they 'draw current' pretty easy and fry out if u forget to disconnect the rca's from the amps and mess around with the power wires...try another HU and see what happens

Try another head unit? Haha, well thats not going to be possible for me. Seems stupid they have a fuse in there, but must be for a reason.

Know wher this fuse is so I can check it?

 

[rrmccabe 10+ year member]

As a test today I made a cable with a ground wire coming off sheild. Below you can see a picture. My Constant noise went away !

I have a few odd sounds like when my heated seats cycle but not bad. I plan to do the other 5 cables.

Good old Pioneer ground loop !!

 

[helotaxi 5,000+ posts]

Have you tried simply a different set of RCAs?

 

[rrmccabe 10+ year member]

Have you tried simply a different set of RCAs?

Yes, nothing special but a set of cheap 6 meter ones that came with my 4 gauge kit. Sounded the same as monster cables. Its definitly a ground loop issue.

Its amazing, if you do a search for ground loop or speaker noise, Pioneer is the headunit 90% of the time.

Just made 3 more and will install them tomorrow so I have all covered

 

[zeuolaxxx 10+ year member]

Pioneer is the headunit 90% of the time.

x2

 

[helotaxi 5,000+ posts]

You said you get the noise with the car off, though? A ground loop picks up alt ripple. If you are getting noise with the car off, you are getting something else.

 

[rrmccabe 10+ year member]

Ground loop will pick up any kind of noise. Not just alternator. Noise is noise.

 

[helotaxi 5,000+ posts]

Ground loop noise is caused by the alt ripple getting into the signal path because, due to a bad ground, one component in the signal chain grounds through the signal cable to another component in the chain. Not an issue with the car off because the ground current doesn't have the ripple from the alt since the current is coming from the battery not the alt. If grounding the RCA barrel fixes the problem, great, but you have something other than a ground loop issue.

 

[zeuolaxxx 10+ year member]

I had the noise when my car was off or on.. then I did the ground loop and the noise disappear !