Right Rear speakers dead.

[Liland]

Hi i have a 2012 Golf Mk7 with a speaker problem. My right rear door is dead, i can hear a low buzz from the speakers but no sound. I used the right rear to tap into with my sub woofer install (from behind the HU) and i have no problem with the subwoofer working. So it seems to be ok from the HU and out.
What does the audio signal go via between the HU and speakers?

This is a non Dynaudio car, just standard audio system.

I have removed the subwoofer install, but no change. Wiring behind the HU (aka the cd rom unit).

Aleksander Liland

 

[southpawboston]

If you can hear a low buzz from the speakers in that door, then it does not sound like a wiring issue, but more of a signal issue.

Do you hear both the woofer and tweeter? It is possible one is shot, but if that's the case, the other should still work.

 

[Liland]

Low buzz in both, so i agree that the wiring is ok.
I have been playing music with the volume all the way to 11 for periods up to 5 min, so maybe the extra strain with a signal output on the speaker channel have burnt something?
Is there an amplifier or such between the media unit and the speakers? Any experience in where it might be if so?

 

[Adurm]

I'd check the tap.

 

[Liland]

Checked and removed. No luck.
Buth thanks, no tips are too silly. I have no problem overlooking the simplest of things, so any input is good

I'd check the tap.

 

[Adurm]

There shouldn't be an amp from the glove box to the speaker. I've heard of moisture collecting in the door panel. Maybe the terminal is corroded. Sucks you have to drill the rivets to get the speaker out. But i think the terminal is accessible from between the metal and door card.

 

[Liland]

There shouldn't be an amp from the glove box to the speaker. I've heard of moisture collecting in the door panel. Maybe the terminal is corroded. Sucks you have to drill the rivets to get the speaker out. But i think the terminal is accessible from between the metal and door card.

Had the door card off, nice and dry and no corrosion.
But being that on the output of the media unit only has one output for right rear speaker, and it being two speakers in the door, one mid/sub and one tweeter it has to be a crossover or slimilar [emoji848]
Will remove the door card again and see.

 

[Adurm]

I think the tweet has a capacitor on the back of it. Might be able to test each speaker with a multi meter. Dont know if it would show if one is blown. I suspect if one is, then neither will work as they are wired together.

 

[southpawboston]

Had the door card off, nice and dry and no corrosion.
But being that on the output of the media unit only has one output for right rear speaker, and it being two speakers in the door, one mid/sub and one tweeter it has to be a crossover or slimilar [emoji848]
Will remove the door card again and see.

There's no "real" crossover-- just a high-pass filter (capacitor) in-line with the tweeter. Other than the capacitor, the tweeter and mid-bass driver are just hooked up in parallel. One can operate without the other.

However, it's possible, if one blew, and the voice coil melted and shorted, it could have blown the amp channel.

The best thing to do to diagnose this is to remove both rear door cards and swap mid-bass drivers. If the left driver works fine in the right door, then the problem was with the bass-driver, but if the left driver doesn't work in the right door, the problem is in the head unit.

 

[overmonk]

The best thing to do to diagnose this is to remove both rear door cards and swap mid-bass drivers. If the left driver works fine in the right door, then the problem was with the bass-driver, but if the left driver doesn't work in the right door, the problem is in the head unit.

You might be able to just temporarily patch one side to the other with ~4' of speaker wire - all you need to know is if the channel works. This way you wouldn't have to deal with drilling out rivets unnecessarily.

 

[Liland]

I did just measure the Ohm in the connectors behind the media unit to measure resistance all the way from the pin to the speakers. All channels had a recistance of 3.8 Ohm. If the speakers is blown wouldnt it be some resistance difference?
Suspecting the media unit to be the problem..

 

[southpawboston]

I did just measure the Ohm in the connectors behind the media unit to measure resistance all the way from the pin to the speakers. All channels had a recistance of 3.8 Ohm. If the speakers is blown wouldnt it be some resistance difference?
Suspecting the media unit to be the problem..

Correct. I suspected the speakers were okay since you get a slight buzzing out of them. Sounds like a blown amp channel from the head unit (media unit).