: funky wiring in A/V inputs in console?



Dj Brady
08-20-11, 05:01 PM
My left input only plays on the right and the right input plays a blend of left and right (center, but will play panned to either side). This was diagnosed using "normal" audio position setting and using the left/right panning adjustment to determine where the audio was being sent via the left and right (white and red) A/V inputs.
Anyone else have this issue? I would have searched but I had no clue how to word this question.

Dj Brady
08-21-11, 11:36 AM
soooo... no audio freaks in here like me, huh? :)

EChas3
08-21-11, 05:55 PM
It sounds to me like your DPO 'improved' your Aux inputs. Perhaps another member can share the procedure to check the Aux wiring.

Dj Brady
08-21-11, 09:42 PM
I just can't wrap my head around why right (red) would direct audio to only the left speakers (which, of course, is the wrong side) but the left (white) actually pushes audio to both sides.. that sounds like some spliced wiring (or funky programming in the head unit, if this would be possible).. it's like the left is being seen as a 'center" signal. I can pan it to both left and right sides, where as when I have signal plugged into just the right side, I only get signal on hard left.
I hope this is making sense. If things were working correctly, plugging into red would only give audio on the right side and white would only be on the left side. As it is, it's A: reversed for right input and B: center for left input.
Very strange...
I'm still reading on how these GMLAN systems work... would this be one of those situations where pulling the battery cables and shorting them to "reset the system" would be an applicable tool? If I do that, what settings and data do I lose?

EChas3
08-21-11, 11:01 PM
The system reset should at most require you to retrain the express windows up position. I doubt this would affect the Aux Inputs at all. It's just old fashioned line-level audio (aka baseband); nothing digital at all.

Have you looked at any of the wiring to see where the DPO might have molested it? I'm thinking you'll learn a lot when you pull the nav/radio head-end. I'm virtually certain that you'll find a pin or wire pulled/jumped.

The wood-veneer bezel is all push-fit but is thin around the ashtray. I use putty-knives covered with a layer of cloth to genty pry it up and off. The Lockpick instructions show it well.

dkozloski
08-22-11, 01:20 PM
Are you sure that you're using compatible pin plugs to make the conection? Maybe there is something finarky there.

Dj Brady
08-22-11, 02:18 PM
Hey Kozloski, yeah. I'm pretty handy with a/v hardware. It's pretty hard to screw up RCA cables. Red to red and white to white. (as far as the audio part is concerned). I've not hooked up a composite video source to check the video input yet. I'm curious about now that I'm thinking about it.
The right input sending audio to the left speakers is bad, just because it's not right and if the left input sent it's signal to the right, then I'd deal with that but the fact that the left input sends audio to both channels, that has me curious and concerned. It's not just an issue of a plug being reversed by but either a wire spliced to both channels or a deeper issue with programming in the head unit.

dkozloski
08-22-11, 03:49 PM
It's not unknown for somebody to try to stick a stereo plug into an RCA jack.

kschwed
08-22-11, 04:13 PM
I have not actually used my AUX input, but I think yours is functioning correctly. If I recall, when you plug in the red composite (supposed to be the right side), you will get audio from both channels because the system thinks it is a mono source. This applies to all AV hardware as far as I know. When you say right goes to the left, are you saying that the red connector goes to the left or the white one goes to the left?

Dj Brady
08-22-11, 05:10 PM
Kozloski, I know what you're saying but even if I stuck a stereo signal into one of the av inputs, it should still only go to the side associated with that input.

Schwed, I'm familiar with the wiring architecture you're referring to and you're right, that could have been a possibility BUT once I plugged in the other cable, the signals that should have been discrete left (which should be right but the inputs seem to be flipped) should go HARD left but they don't they're still mixed in the middle.
And to alleviate any concerns, this is with the audio positioning to "normal" or whatever the 2ch stereo settin is called and not "driver" or "rear seat" positions.


And to reaffirm, yes, red is goIng to the left side, yet it's labeled right (as with all conventional a/v inputs)

EChas3
08-22-11, 10:08 PM
An Apple device with many non-Apple cables will produce odd results. Try a different soutce to be 100% sure.

In my experience, few jacks loop the red jack to both channels when the other jack is not used. Maybe some do, but they are rare.

Dj Brady
08-22-11, 11:07 PM
An Apple device with many non-Apple cables will produce odd results. Try a different soutce to be 100% sure.

In my experience, few jacks loop the red jack to both channels when the other jack is not used. Maybe some do, but they are rare.

Yeah, I'm aware of the "non apple" cabling issues, but again, the issue is not from the source, it's the receiving end. No matter what I plug in as a source, the signal plugged into the Red (Right) jack in the console sends audio to the Left channel of the stereo.

And the "single channel defaulting to mono/center" is always, in my experience, Left channel input.

I didn't get a chance to tinker with it this evening, but I intend to pull the head unit and cabling soon and track it down.

To elaborate, I'm not just plugging both cables in and saying, "Hey, the signal is swapped".
I'm plugging a single cable in at a time and weighing results.

dkozloski
08-23-11, 04:38 PM
I've seen systems that operate exactly as you've described but when both cables are plugged in the R channel is subtracted from the R/L internally to give a clean L to go with the R and you're good to go. I'd be looking at the amp or DSP. Also you might have an input cable with the signal and ground swapped.

Dj Brady
08-23-11, 08:24 PM
You mean a signal + - swapped? That would just put the audio out of phase. I'll look more into the matrices mono input. With the red/white backwards, that might make some sense. Let me do a little more digging. I might be coming back with a sheepish grin. :)

sba300
08-30-11, 09:26 PM
The white is meant to accept mono inputs as well...so it pumps out to both sides. when in stereo mode, they work as intended. plug both in together for the intended effect.

dkozloski
08-31-11, 12:59 PM
The white is meant to accept mono inputs as well...so it pumps out to both sides. when in stereo mode, they work as intended. plug both in together for the intended effect.
Exactly.

Dj Brady
08-31-11, 07:40 PM
Yeah, I got my new a/v breakout cable for my iphone yesterday and was testing it and I see what you're saying about the left input being mono when it's the only one plugged in, but it STILL gets its left signal from the right (red) input, so I guess my red and white have been switched at some disassembly process. No huge deal for any music I would listen to, but if I'm watching a movie on my iphone, the audio would be flipped from the action on screen.

sba300
08-31-11, 10:09 PM
if that is your concern, just plug the red from the breakout cable into the white port, and the white into the red port. unorthodox...but it should work if the audio is merely flipped.

Dj Brady
09-01-11, 01:33 AM
if that is your concern, just plug the red from the breakout cable into the white port, and the white into the red port. unorthodox...but it should work if the audio is merely flipped.


*chuckle* Kind of goes w/out saying, doesn't it. ;)

tomm
09-01-11, 03:16 PM
The white is meant to accept mono inputs as well...so it pumps out to both sides. when in stereo mode, they work as intended. plug both in together for the intended effect.

This is correct. With only one input it would put sound across all speakers as if it was a mono signal. When both are connected the audio should keep both the left and right separate.