So I had spend some time in my old 944 last week while I gave the MINI some time off daily duty to rest her faulty ball-joint, and it sort of turned into an interesting comparison of stereo equipment... The 944 has a very nice Polk system that I installed myself, and I have always found to be extraordinarily accurate when fed good source. The one letdown is that it's a self-installed system that doesn't have the advanced acoustical tuning of a factory system. Now that I'm back in the MINI, I'm feeling that the clarity of the highs is not quite where it could be...

I'm all for the idea of popping in a higher-end tweeter, but I don't want to destroy the very good acoustical tuning that the H/K system seems to have either. Has anyone had any success with aftermarket tweeters?

 

I don't have the HK system, but I would guess that it does not have any kind of crossover circuitry. The standard system uses a small resistor attached to the tweeter to limit the watts, or noise, or something like that. If you were to just replace the tweeters, it would no longer have that resistor. That could cause damage or distortion to the new tweeter as it tries to play frequencies outside it's range.

Basically, if you replace a tweeter, make sure you have crossover circuitry.

 

Indeed. They typically come with a basic crossover to avoid the damage you mentioned.