Subject: Comparison HK system vs Aftermarket upgrade
I have to admit that there was a time that I almost regreted not getting the HK upgrade. The stock system is not better than the average stereo found in a $15k-$20k car. Its sound was very muddy in the low midrange, virtually non existing high and very distorted bass. About the only good thing that can be said about the E46 stock radio is that it is a ten-speaker system. I was lucky enough twice in getting a loaner with HK stereo upgrade. It is a better sounding system than stock. The high's is better, the bass is stronger but very muddy, and the midrange was more neutral but still had a touch of muddiness. Overall, it is a very acceptable system but not great.
However, after upgrading my E46 amp and four speakers with rather modestly priced aftermarket part, list for amp and four coaxial spearker is $450 plus installation (my case $0), I no longer consider the HK upgrade a worthwhile option if you truly really enjoy hi-fi music reproduction.
My current stereo system in my E46 consists of original radio/cassette unit with cd changer, a pioneer 4-channel amp and a Boston Acoustic coaxial speakers for the back and Infinity coaxial speakers on the front. The original tweeters and midranges are disconnected and not in use.
The sound now is just amazing considering the use of modestly priced component. It is way more clear from the low frequency to the high and can be played reasonably loud without any hint of audible distortion.
But the most amazing improvement is in its imaging and wider soundstage. The sound no longer appears to come from the door panels plane but from 3-6 feet behind, similar to the sound enhacement button on HK but way more natural. There is also a more perceived space separation between instruments and/or singers. The bass is strong and lot more accurate (than HK) though it can benefit from an addition of a subwoofer.
Originally I was concerned about the position of the tweeter in coaxial speakers (too low?), not to worry, the high does not seem to come from floor level but about door trim level. Thus coaxial speakers work really well in the front of a E46, I can't say the same on an Integra or ML320 that were installed before.
I am now really considering replacing the front speakers with one from MB Quart or a/d/s. ;-)