Hello guys,
I also installed a RCD330G Plus 187B HU in my 2012 VW Polo.
All is working great exept...the sound, which is very bad compared to my old RCD 310 HU.
I've been looking for a week how to improve the sound (by adjusting Bass/Middle/Trebble but also the equalizer on my phone) but that was unsuccessful. The basses are definitely weaker than before and the sound is getting really dirty when increasing the volume.
However i think i've found the problem : RCD330 is removed from brand new vehicles in China (usually Jetta, New Santana...) and they usually come with only a four speakers audio system (2 tweeters+2 mid-range speakers). My car has six (2 tweeters+4 mid-range speakers).
So I tried to set all the volume in the back of my car (using the Balance/Fader setting on the HU) and only a low and muffled sound was getting out of the speakers !
For those who have at least 6 speakers in their cars, tell me if your speakers are working the same way in the front and at the back of your car.
The solution might come with VCDS but every time we try to modify the code (from 2 speaker channels to 4 speaker channels in Byte 2) we get "Error 31: Request out of range". I think this operation requires a "security access code" in order to be accepted.
Unfortunately I don't have it and I don't have the skills to find it.
I'm currently talking with the man who sold me the HU to fix that issue.
I'll keep you posted.
PS: If anybody has a question about this HU, feel free to ask