Something about Thiel CS 3.7

Hello Guys,
I own since ten years the Thiel CS 2.4 (not SE) and I'm still happy with them but someone offered me the Thiel CS 3.7 as change with some added money.
Theorically should be an improvment respect my 2.4 expecially regarding the easyest load .. my 2.4 run with Primare A32 solid state amp.. that does a good job on them.
The 3.7 reading specs has 90db efficiency and 4 ohm load with a minimum around 2.3ohm while my 2.4 87db same 4 ohm load but a deep around 1.2 ohm .. not easy for amps.
Someone here tried both? .. and what do you think about?
Thanks in advance for your reply!
Hi Dweller,
Thanks for your opinion .. so do you think the 3.7 are a step up respect the 2.4?
It's been a long time since I was on my Thiel journey, but I went from 1.6s to 2.4s and had every intention of moving on up to 3.7s until Jim died and I decided to go a different direction.

In all that time of lusting after the 3.7s, I never once read about the 2.4s outperforming them.  As @dweller stated, my every impression was that they were a big step up.  If you're committed to Thiel, then I think 3.7 vs. 5i vs. 7.2 is more debatable.  I personally would go the 3.7 route.
Depending on the size of your room, the 3.7s should be a significant step up.  They'll certainly go deeper in the bass.  Only concern could be overloading your room.  You might check the Thiel Owners thread, lots of knowledgeable Thiel owners there.
Yes, 3.7 should be a big step up (if your room is small, maybe not so big). Thiel's are quality no matter what size. Some of the best sound I've heard was from the 1.6s in a mobile home with a BAT integrated. I've also owned the 2.4SE which was stunning. The ONLY concern is getting service if anything should break (company out-of-business). I think Jim's brother is providing service now so you might want to inquire before purchase. 
I own the 2.4 and have also had them a long time. I demoed the 3.7 a number of times. The 3.7 is in a another league. It is an amazing speaker. Today it would cost $18k or more if it were still out. 

It will do everything your 2.4 does only better. They are cut from the same cloth so it will be evolutionary rather than different. I would take that upgrade in a heartbeat. I don’t know your amp but I heard them on a musical fidelity A5 (“cheap” integrated) and it blew my mind. I am more jaded these days as I have been exposed to a lot more stuff.  

Thiel 3.7’s great speakers, when driven to get their best. Very low impedance, need an amp that does current real well as Stereophile says. " mandating use of an amplifier that has no problem delivering high currents".

But my god are they ugly as sin, remind me of Daleks in Dr Who.

Cheers George

I concur with james633. Feel free to join us over on the Thiel Owner thread.  You find find several CS 2.4 and CS 3.7 owners on The Panel.

Happy Listening!
Look at my Virtual System photos to see a 3.7 in a small room. It sounds perfect but I had to use DSP via Convolution files and also acoustic panels. Well worth the effort for me.

I even replaced both COAX drivers with and new ones. The bass drivers were recently replaced by the prior owner. Very easy to do this and this was the first time I ever did anything like that. So I feel like I have a brand new speaker.

A former Thiel service tech has all the old Thiel parts and is an amazing help in getting the Thiels to work perfectly.
I am testing the CS3.7 at the moment with the following 3 amps.

1) Krell K-300i integrated + Audio Mirror Tubadour III SE DAC
2) Benchmark DAC3B | HPA4 | 2 x AHB2
3) CODA CSiB + Audio Mirror Tubadour III SE DAC

One of the Krell or CODA will sadly depart (I think). The Benchmark stack is not going anywhere.

@georgehifi. You should see how ugly mine look with my custom paint job. My wife is not a fan of the looks.
  1. strongly agree, seek out the recommended Thiel thread. Rob at coherentsource has what parts he has, would be good to touch base with him on what he has for both. Some parts are now sadly unobtainable. There are a wealth of friendly folks on that thread.
  2. best to you
I agree with Dweller.....they are excellent speakers and deserve the best input you can provide.
@georgehifi. You should see how ugly mine look with my custom paint job. My wife is not a fan of the looks.
Yep, magic sounding, but they're a speaker only the mother could like, and he's no longer with us, rip Jim.
Cheers George
Recently I was fortunate enough to snag 3.7s around the 1st of the year. They were serviced by Rob at Coherent Source before I got them to replace my 3.6es ( loved them). I have not heard the 2.4, but I can say without hesitation that the 3.7 was the Thiel flagship for good reason. They offer extreme clarity, speed, coherence and grace, and refinement that is among the very best available. That said, system and room matching are absolutely critical to get the most from them. If you get it right, the rewards are well worth the effort and cost IMO. From years of Thiel experience (2 2s, 3.6es, and now 3.7), there are some guidelines that may help.

 I never wanted to do it, but tube anything tends to relax Thiels. My best advice is to include a high-quality tube preamp/linestage. As important is to choose an amp that can pass large amounts of current. If the amp can double its power when the impedance falls by half, you are going in the right direction. Finally, you need to be at least 8 feet away from the speakers to have them sound their best. That plus maybe 3-4 feet of clearance behind the speakers and another 3-4 feet behind your listening position. You should also have room to keep them 3 feet or more away from sidewalls. Tubes matter with Thiels, high current amplication matters, and your room definitely matters, a lot. Here are some additional thoughts that I have found useful-

and from Stereophile-

"Editor's Note: Class A "Loudspeakers" are sufficiently idiosyncratic and differ enough from one another that prospective customers should read Stereophile's original reviews in their entirety for descriptions of the sounds."

Perhaps a listener should trust their ears in their own particular situation rather than taking as gospel what reviewers publish. However, reading reviews can offer good guidance on how one might get the best from such beautifully conceived and executed "Class A" instruments. The Thiel 3.7 is certainly, within its limits, a beautiful loudspeaker. It should, given the right set-up and support gear, easily surpass the performance of the 2.4 IMO. 

Hegel Mohican CD
Audio Research Reference 3 Linestage
McCormack/SMc Audio modified DNA 1 Amp
Shunyata Alpha HC power
Kimber Monocle XL speaker
Audioquest Columbia XLR interconnects
Audioquest Niagra 1000 power conditioner


I'm a long time Thiel fan, had listened to the 3.7s, the 2.4 at one point long ago, had the CS6, 2.7 and 3.7s.

The 3.7s are the best speaker Thiel ever made, truly a culmination of his engineering talent and what he'd learned up to that point.   All sorts of innovations put them beyond the 2.4.

The coax drivers are more detailed, yet more relaxed and organic, than previous generations.   I've had many speakers but the 3.7s were probably the best: massive soundstage capabilities, but with super image precision and density, completely coherent from top to bottom in a way that make most other speakers sound like they are "trying."I auditioned a long list of current speakers and overall I found the Thiels performed better.

I had to downsize a bit to the 2.7s which are amazing, though not quite on the level of the 3.7s.

So, yes, the 3.7s would certainly be a step up from the 2.4s.

The 3.7s reached such a stage of innovation and refinement I'd feel confident many other speakers will be playing catch-up (and many failing) for years to come, to match such a coherent collection of traits in a speaker.
You can make a 3.7 sound great in a small room. Just need to select the right approach.

With my Class A stuff I found a tube based DAC really took the sound to a nice level. Great synergy.

With an all Benchmark stack using AHB2 monos, which is not warm sounding gear, I was also able to get tremendous sound. This is also what I use the most. The tube DAC was not a good with the Benchmark.

I think the Thiels pump out what you put in. When I have gear with great synergy the sound I from the 3.7 is great. Either warm gear or neutral gear. You do need a lot of power and my 3 amp choices are more than 300 watts at 4 Ohm. I definitely notice the difference with using about 180 watts at 4 Ohm. The sound did not open up as well with the bigger power.

My 2 cents if you really want to know how a 3.7 can sing try tube monoblocks like Jadis or VAC.

I've tried all kinds of SS amps with them but the best results i got by far is with PP tube amps.


it appears that Curio has disappeared? Thank You for suggesting Tube amp(s) for the CS 3.7 loudspeaker.


Happy Listening!


Nice post and well said. Recently, I added a Hegel Mohican CD player to my collection. This spinner compliments AYRE gear very finely.


Happy Listening!