TSB 2052251/4 Bang & Olufsen: Audio distorted from all input sources
 

I just noticed this TSB, which some people may be hearing the effects of.

TSB # 2052251/4 June 25, 2020, Bang & Olufsen: Audio distorted from all input sources

Link >>https://static.nhtsa.gov/odi/tsbs/20...76853-0001.pdf

"Customer states:
The audio sounds distorted from the door speakers or the subwoofer.

The vehicle is equipped with the Bang and Olufsen sound system.

Technical Background
Software parameter allows the speaker to be overpowered, resulting in distortion.

Production Solution
New software in the sound system control module, J525 (address word 0047) addressed the condition.
Service

1. If the concern is not due to outside influence, continue to Section 1. Outside influence is outlined in TSB 2018187: 91 Sound system: speaker rattles, vibrations or audio interference.
Section 1: SVM Update Instructions

2. Follow all instructions in TSB 2011732: 00 Software Version Management (SVM), operating instructions.

3. Update the sound system control module, J525 (address word 0047) using the SVM action code as listed in the table below, if necessary:"

>>>> in the document is a Software Update Table <<<<<

"3. Following SVM update, recheck system. If concern is still present after SVM update:
If concern is related to the subwoofer, continue to Section 2.

If concern is related to the front door speakers, continue to Section 3.

If concern is identified as another source, continue outside of this TSB.

Section 2: Subwoofer
If the source of the distortion is identified as a subwoofer with part number 8W9.035.382.C:

4. Replace the subwoofer

5. Continue to Section 3.

Section 3: Front door woofers (left and right)

4. If the source of distortion is identified as a woofer with part number 8W5.035.297 replace both the driver and passenger door woofers.

Tip: Due to the differences between the updated woofer and the original woofer it is not permissible to have unmatched woofer between doors. Therefore, replace the affected woofer in both the left and right front doors."

Wow, this is both interesting and concerning considering the quality standards that both Audi and B&O should be holding.

Thanks for this! I had this issues on my driver side door (2018 A5 SB) and was intermittent. Some times it would sound fine other times sounded like a blown speader. Didn't make any sense. Took 3 dealer visits until they finally "heard" it and changed the speaker. I'll have to find the service ticket but pretty sure all they did was replace the speaker and not the TSB.

Strangely enough recently I thought I noticed this happening again and this TSB would explain why it could be happening again. I'll need to print it out and mention it in my next service.

Recently took my A5 in for it's 40k service and I provided them with this TSB. They confirmed it applies to my 2018 with B/O and completed the software update.

Sound is completely different now, in a good way. It actually has bass, so much so that I had to turn the bass down. Can't thank you enough for posting this TSB.

For anyone complaining about lack of bass check the attached TSB and if it applies have your dealer complete the software update. Then decide of you still need to go after market. Good Luck!

Do you have the MMI version of your car, before and after this update. That might prove useful for others.
If you have an autoscan from VCDS or similar before and after, that would prove invaluable because then we will see exactly which modules in the car received the update to resolve this problem. Because with B&O, the amplifier is an active module with its own firmware. So the fault could have been either in the MMI HU or the B&O amplifier.

Do you know if they replaced just the speakers or also the subwoofer? The TSB says to replace speakers 8W5035297 with 8W5035297A. But for the subwoofer it says to replace 8W9035382C with 8W9035382C (same part number).

This B&O TSB 2052251/4 is an update for J525 which is the B&O amplifier in the trunk.

"Update the sound system control module, J525 (address word 0047)"

https://cimg7.ibsrv.net/gimg/www.aud...a8278337b6.jpg

So I just called my dealer to (finally!) schedule the airbag wiring recall fix.

I mentioned this TSB. He says they won’t do a thing until I bring in some music and prove to their satisfaction there is “distortion.”

I guess I can play “Bat Out of Hell” at full cranked volume, or I can say screw it. As I’ve mentioned before I don’t have a good musical ear, but even I can say the bass is poor.

I printed out the attached TSB, my Service Advisor looked up if it applies to my A5 and then took care of it. I did hear & have the distortion, which basically sounds like a blown speaker. If you aren't sure what that sounds like it's sounds like thick ripped paper vibrating (which is all a speaker is basically made of). And what makes this issue strange is one day it sounds blown and the next time you get in the car everything sounds fine. If your vehicle qualifies based on what is listed in the TSB and the dealer refuses to make the update b/c they can't replicate it you should call BS because the issue is intermittent anyway. My wasn't doing it at the time I took it in and they still applied the update. Hope it works out.

Thanks. My service advisor wasn't so pleasant about it on the phone. He said I'd have to demonstrate it in front of him. We'll see. I've known him for twenty years, but I'm not the best of customer. I buy a new car every 12-15 years and what maintenance/repairs I don't do myself I take to an independent shop.

But you'd think that just loading the new software wouldn't be a big deal since the TSB says "Software parameter allows the speaker to be overpowered, resulting in distortion." They'll have my car in anyway doing the recall.