Audi A3 8P with Bose needs 4.0 instead of 4.1

[Sebbel]

OK, now I found a solution. Now I got Bass again.

Sadly, I installed an older Android 4.4.4 to my device - can you tell me a download-link to an Android 5.1.1 for the RK3188 MTCC 1024x600? - Thank you.

EDIT: Forget the idea about diodes, it has only been a placebo for me.

[Jammy]

Hi, glad to hear you got Bass again.
About the android 5.1.1 for the RK3188 MTCC, as you know that we do have the 5.1 Andriod now, 
but I am so sorry to tell you that 4.4 Android can't be updated directly to 5.1 Android because of the machine firmware' limitation. 

That means the unit with 5.1 Android system has its firmware programming into the unit without being able to change, which has the same firmware limitation with some other 4.4 or 4.4.4 Android unit. Our technician and factory professional man have test so many times , and they found the limitation of firmware would be disordered and caused lots of problem to the unit when updating the 4.4 unit to 5.1.
So, to avoid any unnecessary problem to our respected customers,we won't suggest you to update the unit from 4.4 to 5.1. 
Regards

[Sebbel]

Hey Jammy,

I tried alot with the unit, now It works fine with an alternate firmware (Mal*y*k) on Android 5.1.1, so this issue is solved for me.