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Hello dear audiworld members, Lately i have observed that my Audi A4 B9(2017), MMI, doesn`t have the menu for B&O subwoofer adjustment. A friend of mine has the menu on his car. So, after searching online to resolve the problem I found 2 solutions. The first is to code the MMI with VCDS, but one downside would be that the graphics of the MMI would show a Audi Q7 instead of Audi A4. The second method is described on the attached TSB and involve the firmware update of the MMI unit. Is is possible to update the MMI unit using a SD card and the engineering(red) menu? If so, is there a tutorial for this operation? I don`t want to fu#@k up my headunit.
Thank you! MC-10155723-9999.pdf
Last edited by Alexandru.k_24; 05-18-2021 at 02:27 AM.
If you have a Nvidia Tegra unit there is no update that can bring the subwoofer control.
The only solution I've found after lot of digging is to change the MMI car model to q7.
In the TSB, in the SVM code for A4, you get a point that's for Qualcomm: MHI2QUS5087
Trust me, I've checked every TSB related to subwoofer control for A4, and nothing for Tegra. Only for Delphi units and units with Qualcomm SoC.
The latest version is K3346, it doesn't come with subwoofer control. I am on K3344.
So, basically i have no chance to activate the subwoofer menu without having the Q7 graphics? Holly sh@$%#t these Audi`s are driving me nuts. At least, after the activation of the subwoofer control and having the Q7 graphics the sound is better? Right now, when playing music at high volume, the door speakers seem not to handle the power and you can notice the bass distortion. Maybe if we can lower the bass settings from the speakers and increase the volume of the subwoofer would be better.
Well...thank you. I will try to activate the subwoofer control with VCDS, just to see the improvement. As for that TSB, it involves to replace the front door speakers (240€/piece) and a potentially faulty subwoofer (another 240€). At that cost we could easily replace the stock B&O speakers with some aftermarket speakers that are way better. Before this Audi A4 with B&O sound system, i had a lot of BMW`s with Harman/Kardon sound installed. Never had any problems with those systems regarding sound quality at higher volumes. B&O system is a bit disappointing . Also i will try to update the mmi and sound system control module to the latest version.
In that TSB it's also noted an update to sound system parameters via ODIS SMV Code, so it's not only about upgraded speakers.
You can easily check if your car has been parametrized:
Originally Posted by Void20
Control Unit 47: Sound Sytem Advanced identification (after SWM update 47A006, TSB 2052251/4)
Parameter set part number: 8W0909510VF
Notice, I have the older speakers (8W5035297, without A). I do notice a slight buzz comming inside the front door speakers with some bass frequencies (not the grille rattles or resonances! that's another aspect I had fixed with textile tape and fonoabsorbant material). Overall the sound quality is good, even at high volume, but I like to keep the bass & trebble bellow mid (12 o clock).
I have also made some soundproofing to the front doors using STP Gold material and some acousitc foam for the rattles. But the speakers themselves are soooo low quality. One of them had the speaker spider cracked in one place . I was about to replace all the speakers in the car (except the subwoofer, wich surprisingly, is fine after a lot of soundproofing and acousitc foam ) but i like to keep the car as original as i can. I like to keep the treble and bass settings at 3/4 volume (3 o`clock). For me, a lot of distorsion coming from the front speakers.
I see, I also went for soundproofing mine, but not sure if it helped at all in terms of sound quality (except the subwoofer / rear deck, but still got rattles there), since there are those acoustic housing from factory.. anyway..
Originally Posted by Alexandru.k_24
I like to keep the treble and bass settings at 3/4 volume (3 o`clock). For me, a lot of distorsion coming from the front speakers.
You can try and play with the subwoofer control and see if any improvement.
If not, I am afraid that you may have to change the speakers to revised part (8W5035297A), but not sure since cannot found any conclusive feedback after and before the change
05-18-2021, 01:46 AM
RO: Audi A4 B9 MMI firmware update
. Also i will try to update the mmi and sound system control module to the latest version.
) but i like to keep the car as original as i can. I like to keep the treble and bass settings at 3/4 volume (3 o`clock). For me, a lot of distorsion coming from the front speakers. 
