My '06 R53 has the factory HK kit. I'm curious what people have found to be the weak link in the system sound-quality wise. As it is, I think its okay....but not really anything special. I've read that the HK amp can be prone to going out, but i'm more curious what people tend to upgrade first in a fully functional system. I have noticed that the Aux input distorts pretty easily, which is kind of a bummer. Aside from that, I would say that the system overall sounds pretty compressed, lacks dynamics and overall just sounds sort of boring. Suggestions on an upgrade path?

 

This is a very difficult question to answer as everyone's ear is different. What sounds good to one person can sound completely different to another. As for my personal input, the H/K is dreadful. There is nothing at all about it that I like. I have a very tuned ear though. I have judged, designed and built many IASCA (car audio sound quality competition) vehicles, so this gives me a completely different set of expectations than you have. What is most important is your impression of it. What YOU do and don't like about it, and then addressing those concerns.