Thiel Owners

unsound - that self-surround does break down over time. At the time we were trying to minimize the standing wave reflections and non-linearities between the cone and surround as well as ultraviolet deterioration of soft plastics. It worked well when new, and held up pretty well. Natural rubber turned out better.

Those woofers are bomb-proof, rarely fail in use.

@vair68robert My Sota doesn't have the vacuum hold down.  Maybe someday.  I use Sota's reflex clamp, which is good, but not as good as holding down the edges of the record.  Prior to the Sota I had a VPI Classic 2 and their periphery ring.  I initially had a hard time paying what I did for a big metal ring, but it was very effective and worth every penny.

bobscliff   check out speakerworks  they have a good video on repairing speakers .

big_greg. I have a Merrill Heirloom TT with an outer clamping ring and I think it makes a big difference , I am surprised that there aren't more TTs with either an outer ring or vacuum hold down . 

As for your 3.6s. have you thought of rebuilding/upgrading your crossovers ? 

big_greg - I’d like to address your brightness problem. It is odd that the Thiels alone are bright among good company. It seems reasonable to assume a speaker problem. I don’t know the 2.3s, but hear that the original tweeter could be heard as ’strident’ and the vented replacement 'fixes' it. I do know 3.6s and the only brightness, stridency, etc. I have found is from a baffle surface propagation phenomenon which is greatly reduced with grilles in place, and is being addressed in my present work.

There is the possibility that something has gone wrong in the XO which is disabling a shaping network in a tweeter or midrange. A physical XO inspection might be in order. But such an instance would be rare, and becomes statistically next to impossible in more than one speaker.

So here's another thought. I’ve had an interesting (disorienting) experience since getting my Benchmark front end yesterday. First of all: it seems phenomenally good compared with the PS Audio Stellar gain cell / DAC and S300 amp. BM is better in every way. The ’interesting’ part is how much more obvious are the cabling differences. I have some Straightwire, Audioquest, Morrow, Mogami, and the standard Benchmark / Canare that came with the stack. Hard for me to believe that the ’normal’ $35 BM interconnects seemed so much more ’right’. Same goes for the speaker cable (with not as much comparison.) I’m in cognitive dissonance since I’ve been doing wire for nearly a half century. I am presently evaluating execution levels in the 3.5 equalizer within two driving systems. The big tip-off was the Bass & Mandolin cuts. I have played the mandolin and was involved in the development of the Collings line. The nuances of chop and gulp, box and ring are in my ear and under my skin. I stopped blaming the equalizer when I added ’straight wire’ to my protocol. When I got to the all-BM / Canare cables things settled into that remembered musical reality. It sounds right and good and I’m not missing those audiophile traits that might be artifacts.

My point is that before you give up on the Thiels, you might make some comparisons with BM cables. The phase / time coherence of all Thiels puts the ear-brain in a different hearing space than do non-coherent speakers. I’ve addressed this idea before, and I admit it can sound hoaky, but my consistent experience over these many decades is that when the system gets right, the speakers disappear. Something smells wrong about your Thiel brightness problem. I hope you can fix it.

Good luck, and keep up posted.