Factory amplifier went bad or speakers not hooked up?

[Zach L]

New to me 2010 A4 P+. I guess I'm looking for advice on where to start troubleshooting. I have a few speakers that are not working. My A4 has the B&O system w/o nav. It's the base Audi concert head unit with Bang & Olufsen option.

Here's what is happening:
Set sound to driver front corner - tweeter/mid work fine, no woofer
Set sound to passenger front corner - no sound from tweeter/mid/woofer (no sound at all)
All rear passenger speakers work fine
Subwoofer does not make any sound

Where would you start? Do the factory amps go bad often in these B8 cars?

Also, I popped open the door to the amplifier cubby in the trunk and found this... looks like the previous owner might have added a sub/amp at one point??? Not sure what to make of it. Any ideas what's going on here? Thanks for any help/advice.

[Vaks]

Seems as if someone has tampered with the oem wiring. I'm pretty sure there was some sort of aftermarket sub added into there. The sub sits under the rear deck and if u lay down on your back in your trunk you can see if the oem sub is plugged in or not. I'm not sure how the B&O system works as I don't have it. Best thing i'd say to do is take it back to the dealer/seller and see what they can do

[Zach L]

Seems as if someone has tampered with the oem wiring. I'm pretty sure there was some sort of aftermarket sub added into there. The sub sits under the rear deck and if u lay down on your back in your trunk you can see if the oem sub is plugged in or not. I'm not sure how the B&O system works as I don't have it. Best thing i'd say to do is take it back to the dealer/seller and see what they can do

Yes, it was plugged in but not making any noise... confirmed by sticking my finger through the grill and it was not moving at all while playing music pretty loud.

Dealer I bought the car from is over 2,300 miles away... plus I bought the car as-is so I wouldn't have any recourse even if they were down the road.

[Audi 4 Life]

If it was working recently and then stopped then I'm guessing there is a short or blown fuse because the wiring was messed with. I would try to find a diagram and check it yourself or take it to local indy or dealer and pay them to repair it.

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[Zach L]

The speaker system has sounded the same since I purchased the car 2 months ago, so likely it's a wiring or amplifier issue. I knew when I got the car that the front passenger corner was quieter, but didn't think it was all three component speakers in that corner of the car. Problems do not suggest a blown fuse, as fuse failure would result in some form of symmetrical outage (all three speakers on driver front side would be out, similar to passenger front side). Also possible some speakers were blown and previous owner/dealership disconnected the specific bad speakers to make damage less noticeable. I worked at a shop while in college and do all my own maintenance and repair, big or small, on the handful of vehicles I currently own... see signature. Total price to fix this shouldn't be over $100 and a few hours of my time. Plus pulling the interior door panels will give me a good excuse to update to the 2013+ chrome interior door switches. :)

I just ordered a replacement amp... I honestly suspect wiring is the issue but the amplifier will be the quickest part to rule out as problematic. I'll pop it in a few days from now and update thread.

[Audi 4 Life]

If the amp was bad you should see codes in vagcom. Throwing parts at it isnt best way to diagnose. I have yet to even see a factory amp go bad.

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[Zach L]

If the amp was bad you should see codes in vagcom. Throwing parts at it isnt best way to diagnose. I have yet to even see a factory amp go bad.

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As I mentioned earlier, I don't believe the amp is the cause; I believe it's wiring three cause. And I agree, not the best but definitely the easiest and least time consuming way to rule out one potential cause. Plus I found a killer deal on the amp so I'm sure I'll be able to get my money back when I sell it. Virtually no time and no cost needed to rule out the amp!

One can suspect there was a minor overheating issue since later part revisions use an updated heat sink design and larger cooling fan in the lower left corner of the amplifier.