Sound quality Dynaudio in the Phaeton GP2 from 2009

Dear Phaeton driver, I bought a Phaeton 3.0 last year. I picked up the vehicle near Munich, because I found a used car with the Dynaudio system there. I like to listen to jazz and classical music, less pop. I had a Fiscon hands-free system installed with Bluetooth A2DP in the vehicle. The sound quality, no matter what source, is an absolute disaster. The middle far too loud, the bass not defined, the heights undifferentiated. I can only bear that very quietly, otherwise my ears hurt. And that’s what I mean as I write it. Before I had a BMW 5 GT with the Harman Kardon system, which was not perfect but light years better than the Dynaudio in Phaeton. Since the Dynaudio was and will be so much praised, I would like to turn to an expert who can help me find the problem. The problem is now that the typical VW operations of sound in the car understand very little. How would you do, maybe someone have a contact for me?