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
The CS 3.7’s flat co-axial drivers mitigate lobing issues significantly. 
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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
I just bought a CS3.7 and discovered a shed load of issues. There is a support person in KY that can provide technical support to resolve all of these problems. If you buy a CS3.7, I suggest you take some measurements to make sure your speaker is up to spec. If you can (with good shipping materials, send it to KY to have the tech guy, Rob Gillum, test it out.

A few days ago Tom Thiel posted a long historical description of the 3.5 and the 3.6. It is on Jafant ’s Thiel speaker thread.
Thanks so much for the very wise advice. The seller shipped the pair to Rob who checked them carefully and listened extensively. They passed his inspection, so I am confident that they will be correct. He did replace a tweeter in one coax, but other than some minor cosmetic issues, he gave the green light. I am hoping to get them installed during the 1st week of December. Thanks to all who posted such insightful comments- I am so pleased with the 3.6es, I can hardly imagine anything sounding much better. But I can try both and decide which to keep. 
That is great that you sent it to Rob. If I sent mine to Rob he would say "no mas".

I also had a few cosmetic issues. The first one being the aluminum shell had a few annoying looking scuff marks. I contacted Rob and he told me to use a specific spray paint on it. I did that and it looks great now.

I had a lot of marks on the veneer and I decided to paint the veneer black to make an all black speaker. I bugged my local paint store half a dozen times for advice before I had the confidence to paint it. That paint job also turned out great. Not as good as a factory job but a ton better than the scratched up used speakers I bought.

I am also putting 2 new COAXs (from 2014) and replacing my COAXs from 2008 and 2012 (maybe keep as backup if they are not damaged). I also got some outriggers in the case my son tries to climb it. I have a feeling my crossovers will need some repair. Fun times.

BTW - I never heard the 3.6 but the 3.7 is one of the best speakers I have heard. I have heard quite a few speakers. The 3.7 always sounded correct to me (my current messed up used speaker notwithstanding).
yabe1951

Nice score! on the CS 3.7 loudspeakers. Your gear is a sonic match for this model. I am especially interested in reading more about the system featuring Hegel Mohican cd player. 
Once the CS 3.7 settles into your room/system, feel free to join us over on Thiel Owners thread. We have several 3.7 fans/owners on the Panel.

Happy Listening!
So sorry to hear about issues with your 3.7s. I hope you can get them up and running. As far as my system goes, it has taken many, many years to get it to where it is. I searched for used gear and bought nothing new. I did have a few issues with some equipment, but I have found the audiophile community to be quite trustworthy. As far as the Hegel Mohican is concerned, I have been pleased, in general. There is information on my CDs that I was unaware of based on what my old player was able to retrieve. The Hegel is analog-like, sweet, and has changed my perception of much of the music I listen to. It has a very low noise floor, great dynamics, and an excellent soundstage; Wide, deep, and fully-formed. There are some things about the function that are IMO clunky and not at all reflective of any product that costs as much as Hegel asks for this machine. 
The problems I am having are somewhat fun since I am fixing them 1 by 1. If it did not cost money I would have no issue at all :). I am learning a lot by the things I am finding. I hope to have everything ready to go either next week or by the end of December. The health of the crossover will determine the timeframe.

I took measurements of the CS3.7 recently with the REW software (free) and a $100 Minidsp microphone. A great learning experience from that too.
Wow! That is a deep dive into the 3.7. I am not that technically competent and have to trust Rob's expertise and judgment. Happy to know that you are learning the details. I do not know if you have seen this or not, but I found it to be quite interesting. Best of luck!

 https://vimeo.com/52026712
What a fantastic video and so helpful to me. I have to solder the COAXs back into the speaker. I will likely also have to remove the crossover. This video showed me how the experts do it and I will copy them. I am not technically skilled in any of this but learning as I go along. I need to practice some soldering before I do the real thing.

BTW - I will post this on the big Thiel thread and put your name on it. All the Thiel folks are on that thread. You will see a A'gon notification when I do that.
yabe1951

it is Amazing what a good CD player can do regarding playback.

Happy Listening!
Yes, indeed. My old player was a heavily modified Rotel RCD 991 with Burson discrete op-amp replacements, a Dexa clock, and some upgraded caps and resistors and damping added. I had an audio grade fuse in there as well. Very relaxed and smooth sounding. Overall, not bad. That player finally quit, hence the Hegel. The Hegel is in another performance category altogether. Bits may be bits, but the timing of those bits is more important than I would have ever thought. The Hegel has greatly improved my enjoyment of CD playback. The only clear advantage the Rotel seemed to have was better sound on the small number of HDCDs that I have. Although it certainly never caught on in a broad sense, HDCDs sound quite good compared with the "normal" Red Book versions. Otherwise, the Hegel player is superior in almost every way. As it should be at more than three times the cost when new. However, I do think that the bass performance of the Rotel was slightly better- More tuneful and with greater weight and authority. The Hegel by comparison is less impactful in the low-frequency range from what I am hearing. Overall, the Rotel player was the least capable component in my system in my opinion and I am happy to have the Hegel player.  

The Thiels arrived from Coherent Source Service by truck freight and I was able to get them into the house, but they are large and heavy. I am taking a break to get the 3.6es out of the room and then unbox and install the 3.7s. I am so much enjoying the 3.6es (the entire presentation is so much better with the new player) that I do not feel any urgency to switch them up. I would like to say a long goodbye to the 3.6es that have given me so much joy over the past twenty-plus years.

 Next up, the last revisions to my amp (McCormack DNA). It is scheduled for upgrades in January with the addition of the new Gravity Base system. I really do not know too much about it, but this is the last major investment I plan to make on the amp. I will be retiring in July, so my plan is to stay at home, sit back, listen, and enjoy.
@yabe1951 My Thiel CS3.7 are really rocking now. You video was an incredible help since it showed me some soldering tricks.

I was going to buy a new DAC and a new amp to make the system sound better. However, after all the fixes and a big DSP tweak no need. This speaker will stay with me till the grave. Sounds amazing now.
Congratulations! Hoping to have a similarly good outcome. I can post some observations in the next couple of weeks regarding how the 3.7s work in my system/room. Happy to hear that you are enjoying your Thiels.

yabe1951

 

Are you enjoying retirement? Thank You for the Rotel vs. Hegel comparison. In 20 years, no doubt, that the technology changed. The 991 is a solid Vintage player. The Mohican is a solid modern player.

Did you upgrade the McCormack Amp?

 

Happy Listening!