whine (I searched)

[bird_dog0347 10+ year member]

Ok, so I have done my homework on this subject but I wanted to ask before I do anything else... I am pretty new to car audio but I learn fast and do research. For those who just want to read the question and try to answer it, here it is... details below the question.

Question:

I have alternator whine when my 2 channel amp is hooked up to my internal speakers, but none when it is not hooked up (just the HU powering the speakers). I have checked, re-checked, re-re-re-re-checked my grounds and even tried grounding the RCA leads. I read that I should see if I get the whine when the amp is hooked up, but the RCA is removed (no power when disconnecting). So when the amp is hooked up to the internal speakers, but the RCA is not, I get no whine. This leads me to believe the amp is properly grounded, and the interference is coming from the RCA. Is this correct, and will a filter fix it even though grounding them did not?

Details:

A few weeks ago I installed an Avic D3X package in my 2006 Silverado 2500 quad cab. I also had a MTX 282 (sub) amp and infinity perfect 10 laying around from an old car I had. I then bought a Mark Antony 2100 amp (2 channel) from a buddy of mine. I used a dual amp wiring kit and part of the wiring that was left over from the previous owner of my truck. It is 4ga power and ground, going to distribution blocks then to 8ga wire to the amps. The RCAs were already run next to the power wire, as well as the existing 9 wire going back to the HU for the interior speakers. I thought this might be the problem so I got another RCA and some more speaker wire and ran it over the seats for testing. This gave it about 4 feet of distance from the power wire (RCA and speaker wire) but it still had the whine. I removed the RCA from the sub amp thinking it might be part of the problem, but alas, still the whine.

When it is just the HU powering the interior speakers, there is no whine, just underpowered speakers. When the amp is hooked up, but the RCA's removed, there is no whine. Will a filter fix the problem even if grounding the RCA's does not? This is getting extremely annoying, and I am tired of trying in vain.//content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif

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[mdillon 10+ year member]

pull the left and right rca's apart into 2 seperate pieces. have someone hold one end and twist the other end by hand or by drill. most of the time just twisting wires can diminish the interference,

 

[bird_dog0347 10+ year member]

So yeah... I have tried everything. I swapped amps, got filters, tried other RCA's, even grounded the amps through the body straight to the frame. I still get whine when I hook the RCA's up to the amps. I have tried pretty much every possible combination, and anything but the LPF gives off terrible alternator whine.

I am done with it. I even ripped out the extra RCA for the second amp as well as the 9 wire. I am going to have a shop do the install on it from scratch and just pay them. If it has whine, they can keep it as long as needed to FIX it!

Any other ideas before I spend the money?

 

[bigbangtheory 5,000+ posts]

When you grounded the RCA's, did it help it at all? I have just a smudge of the whine left in mine, but I cam now stand it, lol! I don't know. Seems you have tried most everthing.

 

[bird_dog0347 10+ year member]

grounding the RCA as well as the filter did nothing. I am at a total loss.

 

[Side Show 10+ year member]

dodgy amp?

 

[savagebee 10+ year member]

try a different amp

eliminate everything as a source of the problem

make sure the speaker leads are not touching @ the amp

 

[bird_dog0347 10+ year member]

I tried two amps, same results. Like I said, the only time it whines is when the RCA is connected but the filters (tried two) did nothing. Both amps gave the same results. I even grounded the HU to the distribution block that is grounded to the frame. I would ground it straight to the battery, but there is only a side terminal for the battery and not one on the top and no post... it is the screw in type and the screw is not long enough to put a ring terminal on it to ground straight to that.

 

[pilyin 10+ year member]

Is your remote wire hooked up correctly and to the right source? That caused alt whine for me once.

 

[bird_dog0347 10+ year member]

I have it hooked up to the remote wire lead from the HU. I guess I could try to move it to another remote source on the fuse box somewhere...

 

[JbIrD 10+ year member]

Are your RCA's run along side the power wire to the amp if so run them along different sides ot the car and make sure they are not close to each other.

 

[bird_dog0347 10+ year member]

Tried that too... the RCA and the 9 wire were running right next to the power wire so I ran another set over the seats for testing, same results.

I did get an idea tonight though. If I got a line out converter and hooked it up and used the RCA off that and did not have the problem, would that prove that the fault is in the HU?

 

[bird_dog0347 10+ year member]

So I traded the RCA filters for a line out converter and it now works perfectly without whine. The HU is less than one year old, would that be covered under any warranty?

 

[its_bacon12 10+ year member]

What do you mean traded RCA filters for a line out converter? L-O-C only converts high level to low level signal..

 

[PaulD 10+ year member]

you have a ground loop between your headunit and amp, disconnect the ground wire from the from headunit that goes into the harness, put a ring terminal on the end and attach it directly to a bolt behind the dash (you may have to add a little extra wire to the ground wire to do this.