Thiel CS 3.6 vs 3.7


Replacing my model 3.6 speakers has come with a great deal of hesitation. I purchased them used from a dealer in 1993 after owning the model 2 2s. I have recently acquired a pair of 3.7s that are shipping as I write this. I understand that "beauty is in the ear of the beholder", but has anyone had both and had a preference? I ask because I do think collective wisdom is important and I do not want to be in the position of letting the "newer and improved" mentality creep into my judgment. What differences could I expect to hear? Context is Hegel Mohican to Audio Research Ref 3 to McCormack (SMc Audio) DNA 1 with almost all mods including Plitron transformer. Balanced throughout with AQ Columbia XLR and Kimber Monocle XL speaker cable. AQ Niagra 1000 conditioner and Shunyata Alpha HC power cables. Thanks in advance.
yabe1951
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I'm a long time Thiel fan -  I own old Thiel 02 speakers, owned the Thiel CS6,  then later the 3.7 and the 2.7.


Been a long while since I heard the 3.6s but I have a decent memory of the sound.


Taste is subjective of course, but IMO Jim's last designs, re-designing the coax drivers, the woofers, drive motors, cabinets etc, further perfected his designs. 



In the old designs I found that they certainly clicked at a precise listening position, but some slight diffraction and lobing effects could be heard with shifting of listener position (a common issue with first order designs).

Moving to the coax designs in the late 90's onward helped somewhat, and helped the speaker's coherence, but the issues still remained audible.  Plus there was a slightly "reductive" quality, where instruments tended to sound a bit more squeezed down than on other speakers.(They were also slightly less bright sounding speakers).


The final design to my ear fixed all those issues.  The coax design in the .7 series sounds smooth as silk, rich and utterly coherent from any position.   In fact, top to bottom the 3.7s were the most coherent speaker I've probably ever heard, let alone owned (competing well with my old Quad ESL 63s). 


So there was the super detail Thiel was known for, but more refined and organic, with just crazy imaging and soundstaging, and the tightes most tonally believable bass.

For me I'd pick the 3.7 in a heartbeat over the old 3.6. 


But, since they do sound a bit different, taste comes in, and if you are used to one presentation you may prefer it.   But the 3.7 to me is what Thiel was always shooting for - a more refined, coherent, natural sounding version of the "Thiel sound."



Just as a side bit of info, they are almost identical ***** to drive, you could almost overlay these two impedance v -phase angle plots. I owned the 3.6's they loved an amp with big current down to 2ohms, (that leaves Class-D, Mosfets and Tubes out)
 https://www.stereophile.com/images/archivesart/Cs36fig1.jpg
https://www.stereophile.com/images/archivesart/1208T37fig1.jpg

Cheers George