B&O Subwoofer Wire Color Code

[Matthar]

My searches have come up empty...

I have a 2018 A3 with the Bang & Olufsen system. I am taking the stock subwoofer signal into a LC2i to drive a JL XD600/1 amp and JL 12W6 Sub. I pulled the back dash apart to find that there are 4 wires feeding the stock sub, not 2 as I expected. The 4 wires are...

white - grey stripe
brown - blue stripe
brown - white stripe
blue - grey stripe

Anyone know what each one of these are? Does the B&O sub have a left and right channel feeding it? Dual voice coil? I just need to figure out how to wire it to the LC2i.

Thanks!

[Matthar]

Alright, I think I figured it out. I'm writing this mainly to document it in the forum, but I would appreciate if ya'all would double check my thinking and reply if you agree/disagree. I sprung for a 24 hour erWin subscription and downloaded everything on my car. On the communications documentation I found that Bang & Olufsen 9VS system amp/control module (component J525 located under the drivers seat) there is a 38-pin connector. Pins 19-22 go to the subwoofer with their polarities listed. I used the find function to look for J525 on the wiring diagram file. Eventually found a page that showed pins 19-22 on the 38-pin connector terminated at a 4-pin connector at the subwoofer. Combining the two sources I get...

Pin #19 = sub (-) = white/grey = pin#1
Pin #20 = sub (+) = blue/grey = pin#2
Pin #22 = sub (-) = brown/blue = pin#3
Pin #21 = sub (+) = brown/white= pin#4

What I interpret this to mean is that the blue/grey and white/grey wires are a +/- audio channel from the amp and the brown/white and brown/blue wires are a second audio channel from the amp. To hook up my LC2i line converter all I need to do is wire one pair to the left channel input and the other pair to the right channel input. The LC2i will do the rest.

Thoughts?

[sbruno624]

Alright, I think I figured it out. I'm writing this mainly to document it in the forum, but I would appreciate if ya'all would double check my thinking and reply if you agree/disagree. I sprung for a 24 hour erWin subscription and downloaded everything on my car. On the communications documentation I found that Bang & Olufsen 9VS system amp/control module (component J525 located under the drivers seat) there is a 38-pin connector. Pins 19-22 go to the subwoofer with their polarities listed. I used the find function to look for J525 on the wiring diagram file. Eventually found a page that showed pins 19-22 on the 38-pin connector terminated at a 4-pin connector at the subwoofer. Combining the two sources I get...

Pin #19 = sub (-) = white/grey = pin#1
Pin #20 = sub (+) = blue/grey = pin#2
Pin #22 = sub (-) = brown/blue = pin#3
Pin #21 = sub (+) = brown/white= pin#4

What I interpret this to mean is that the blue/grey and white/grey wires are a +/- audio channel from the amp and the brown/white and brown/blue wires are a second audio channel from the amp. To hook up my LC2i line converter all I need to do is wire one pair to the left channel input and the other pair to the right channel input. The LC2i will do the rest.

Thoughts?

Hey I just had this done, I don’t have the BO so I only have half the wires but yes, but make sure you get the left and right correct to keep the fader working. Also double check those positives and negatives. On the ACC the positive is white and negative is blue. There’s a YouTube video with a black S3 and he shows you which ones are what, but you can hook up a volt meter and test it with the fader.

Also, I recommend not using the GTO on the LC2i. Wire the amp directly to a 12v turn on.


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