Upgrades for Thiel CS 3.6?


I have a pair of Thiel CS 3.6 that I’ve owned for about 12 years. I think they’re fantastic. 
Just curious... have there been driver advancements that I might benefit from? 
Has anyone tried swapping out drivers and if so, were you pleased with the results? 
128x128gpaulmg1
@jafant - is there something I need to do to get to the Thiel owners thread? I’m not sure how to look it up.
gpaulmg1

I've owned my 3.6s for about 21 years and am experiencing a similar issue. I had my amp (Naim NAP300DR) updated about 1 1/2 years ago and that's when I first noticed an upper-mid/lower-upper harshness and "hashy" sound. I'm still not sure if the issue is in the speakers or elsewhere. I'm waiting for the speaker upgrades to become available and am also looking into a possible component issue. But--the 3.6s are great speakers and worth the effort. 
rosami
I’ve owned my 3.6s for about 21 years
21 years!!! You are a definite candidate for the tweeters ferro fluid clean out and replenish.
"This will make your Thiels sing again, do not discount it as they are well over the date where the ferro fluid has dried out into glug and killing the performance of that great tweeter.
https://forum.audiogon.com/posts/1898655
Your sound will open out more, become more dynamic, even the bass will have better leading edge to it’s snap.

Capacitors on the tweeter are all polypropylene (plastics) and don’t go bad like electros do, which would be on the bass.
Stereophile:
Nearly all the capacitors are polypropylene

Cheers George