Thiel Owners


I just scored a sweet pair of CS 2.4SE loudspeakers. Anyone else currently or previously owned this model?
Owners of the CS 2.4 or CS 2.7 are free to chime in as well. Thiel are excellent w/ both tubed or solid-state gear!

Keep me posted & Happy Listening!

I spoke with Rob, an excellent individual and one of the nicest people on the planet, yesterday. He is in the process of buying the repair service. There is no need to worry. I also asked about the idea of recapping my 3.7s. He told me that would definitely be a plus. He even took the time to mark out what would need to be done on the circuit schematic, and sent that to me. Doesn't get any better than that!
Thanks @tmsrdg! That is a timely phone call! And with fantastic news!

And way cool that he will coach you on the cap upgrades. Please let us know how that goes and how it improves the sonics.
Hi all,

If this report is correct, Thiel Audio is now dead.

Sorry if this has been posted here already, but I couldn’t see it at a quick glance.

Hopefully the Kentucky service dept is poised to rise like a phoenix from the ashes of a very sad corpse indeed.

In over 30 years in brand marketing, I don’t think I’ve ever witnessed such gross incompetence as exemplified by successively poorer management since the takeover.

Effectively the true Thiel passed away with Jim, so there’s little more to mourn now, especially if Rob manages to carry on in a new service business, as is being suggested here.

I have a CS3.5 eq unit that needs a service, but was unwilling to send while the black cloud hung over Thiel Audio. Rob will be getting this work once I hear he has managed to set up service operation. I also have a couple of midranges that could do with some TLC.

It would be nice to think that someone could start making proper Thiel speakers again with all of Jim's concepts intact. Not holding my breath on that one.

It would be nice to think that someone could start making proper Thiel speakers again with all of Jim's concepts intact. Not holding my breath on that one.
If Rob Gillium has the machinery to fabricate the drivers it seems not far-fetched to at least start making CS2.4s again (I know they had problems with the more complex CS3.7 drivers and cabinets at the Lexington facility). Surely, at least a few of their old dealers would be willing to sell some, especially if the crossovers are updated with the latest parts.
I believe they sold off their manufacturing equipment for the most part when they moved to TN.  Maybe they could join up with Tyler for the cabinets?  Was the 2.7/3.7 driver made in China?  I seem to remember reading that somewhere.  I wonder how much it actually costs.  My 3.7s are an early pair, SN around 40/41.  I actually blew a midrange and even though I bought the speakers used they sent me a new one for free.  I haven't read about anybody else blowing one, though, so I'm thinking it's pretty rare. 
Good news for Thiel owners!

Yesterday after the news about Thiel closing, I’d sent Rob Gillum an email inquiring about about replacement drivers for my 2.7s.

I received his reply today.

Rob will be taking over the THIEL Service department - as previous posts have suggested  - and so servicing/parts will continue to be available for our legacy Thiel speakers.

Boy was that a relief!

It really is great news that Rob will apparently continue. Frankly, Kentucky service dept was the only reason I was in the least bothered about Thiel Audio continuing.

Good to see all of you guys. Excellent news and developments on all fronts regarding Thiel Customer Service Kentucky.  May we all continue to enjoy our beloved loudspeakers!

Happy Listening!

Much Thanks! for the follow up- tmsrgd.

Mr. Gillum is a class act.

Happy Listening!

I have to say I was made so anxious reading the news about Thiel last night I actually had trouble sleeping until I found out whether Rob would still be servicing/providing drivers.

I’ve spent all too much time agonizing over which Thiels to keep, and I’ve spent a ton of money on subwoofers, crossovers, digital eqs etc to try to integrate them with the 2.7s. (I should be doing a good test of this sytem this weekend). Given all this, I want to feel secure that I’m building a system around speakers that will be with me a long time, and that can be fixed, in particular if a driver fails. The reports of the coax driver being fairly susceptible to this worried me more. I just didn’t want to live on the edge, having to treat the speakers with the fear of one bad move...and that’s it.

So having the spare drivers available really makes all the difference to my peace of mind.

It was the same with my Hales speakers that I use for my home theater.
Paul Hales wielded absolute magic with his design, the smoothest most organic sound I’d ever heard from metal drivers (and still right up there).
No speaker managed to make home theater listening so easy and smooth while crystal clear, that I could find. Yet by the time I wanted Hales for my system, they’d gone out of business (my timing is perfect!).

I managed to find one of the few remaining pair of T1 Transcendence monitors, and an incredibly rare (huge) top of their line Transcendence center channel made to match the transcendence line. It was just heaven to listen to. any moment a driver could go and that would be it.

So I kept my eye out for another pair of T1s just in case and somehow ended up talking to Paul Hales himself, who sold me the last remaining pair that he’d been using in his office!

Since then I’ve tracked down two spares for the even more rare center channel (they made very few). One complete commercial one, and also the template version - raw MDF no finish - Hales used for to quality check voicing of the other transcendence center channels.

Yes..a bit obsessive about it ;-)

But, the result is having speakers I don’t ever intend to replace in my home theater, and being able to relax about the possibility of failures down the road.

I’ll certainly be stocking up on the Thiel drivers.

(BTW, the fella I'm most envious of is a guy I know who ended up with, what for Hales fans, is the mythical unicorn:  The Hales Alexandria.  It was a new go-for-broke design, the single pair they displayed at a CES, which disappeared because Hales went under shortly after that.  Reports were that the sound was magical.  I can't believe anyone managed to snag those!).

It's nice, if melancholy at the time, to notice the old Thiel Web Blog is still accessible.  Tons of entries from when "Thiel was Thiel."

The announcement of Jim's passing, with plenty of warm and interesting comments:

I now have the JL Audio CR-1 crossover.  I'm going to try and crossover my 2 JL 110E subs with my Thiel 2.7s this weekend.

I'll have to go through your posts again, but do you have any direct advice for me as a starting point?  Crossover frequency?  Crossover slope?  Etc?


Congratulations on your new gear. I think you'll like the improvements. You called yourself a sub newb in an earlier post, but IMO, your previous comments suggest you understand the principles just fine. So dive in and have fun.

My impression is that steeper is better for crossover slope, so probably 24 dB per octave is best on the CR-1. On the other hand, it might not matter all that much since your Thiel mains and JLA subs should both have good linear frequency response in the overlap region, even at 12 dB per octave. Easy enough to try both if you like.

As before, I recommend the Sound Doctor's sub setup instructions here (or see hardcopy with your CD):

As for crossover frequency, here's a range of opinions. Sound Doctor says,

I suggest never going below 80, even if you think your speakers go down to 40, or below. Even in a room where the existing "mains" have a pair of 12" drivers (each) you will get far better results if you ... correctly cross them over at 80, (or higher) ...

The Thiel SI-1 instructions state,

Unless the main speakers are very small, it is usually preferable that this setting not be higher than 80.

There's no explanation for Thiel's recommendation of 80 or below; it might be specific to some feature of the SI-1 or Thiel SmartSubs (probably not specific to Thiel mains because the SI-1 is intended to work with any make of main speakers). Alternatively, it might have something to do with staying well below the frequency at which the period equals the sub's group delay (about 120 Hz for JLA f112s). Above this point, the minimum timing error doubles to 720 degrees. 

Finally, a team of audio pros working with JLA f112's and Thiel CS3.7s chose 100 Hz in this example,

I decided to follow the Thiel recommendation (because I'm working with all Thiel components except for the subs). I selected 80 Hz as my reference but also stored preset configurations at 60 and 70 Hz for comparison. I can switch between these from my listening position with the SI-1 remote, but to my ears, they are indistinguishable. They all integrate seamlessly, and I couldn't reliably detect differences between these settings –– either in the highs or the frequencies surrounding the crossover setting. Still trying to test this.

I suggest you also consider settings somewhat above 80, e.g., 90 or 100 Hz. In fact, I spoke with a support person at JLA who helped an audio dealer install JLA subs, a CR-1 set to 100 Hz, and a pair of Thiel 3.7s. The dealer said it was the best sounding system he ever heard in his space. I would think your 2.7s should not be all that different from the 3.7s. Maybe I'll try up to 100 Hz, too. Can't hurt.

I found the Sound Doctor's Method B (p 4) for adjusting phase and level to be easy and effective. Rather than depend on my hearing, I used a sound-pressure-meter app, SPLnFFT (available for iOS and Android), to easily identify the settings for maximum cancellation.

Good luck!
Attn CS2.4 owners:
I’ve been thrilled with the performance of my "new" Thiels. One parameter lacking, however, was image density. My front wall is ~19’ wide altho’ confounded by a 4x4’ wall jutting in for the rear door exit in one corner. It is ~18’ on the sides. The ceiling is vaulted, 8’ on the front wall and ~12’ on the rear wall. There are two large openings on the rear wall, one just above my head; I sit within 2’ of the rear wall. I think the openings really "save my bacon" from unsatisfying sound with this room.

I did have the speakers about 10’ away from my ears to the tweeters and played with speaker spacing 7-8’. ~7’ sounds best but image density was not satisfying. I just spent most of the past hour experimenting with distance to the listening position, now have the speakers ~9’ from my ears and spaced at 7’ (7’ to the front wall!). Zero toe in. Image density is notably improved.

Anyhow, curious to read what other have for their placement. Thanks.

EDIT: Looks like my spacing is similar to what Shane Buettner used in his review:

Wow, I couldn't have asked for a more helpful response!  What great information.  Thanks for sharing as it will come in very handy!

I'll let you know how things go.

I'm always looking for the most immersive sound I can get, while not sacrificing image density.

For whatever reason, the 3.7s can be spread ridiculously wide and still have focused images.

The 2.7s, which are the next version of your 2.4s, are very good in that regard but don't take to be spread quite as wide.

Still, I've got my 2.7s at 8.4 inches apart, 6 1/2 feet from my listening position, and the image density (their hallmark) is superb.  I just demoed them to a musician friend and the first thing he raved about was the imaging and the "thereness" of the images between the speakers.

My room was designed with an acoustician - it does both home theater and 2 channel listening duty.  It's 13ft x 15ft deep, 9ft ceiling, with a large opening to one side of the room into the hallway.  That opening helps "save my bacon" too I think.  It's a well damped room.

My Left speaker is close to the side wall, near a fireplace with reflective tiles, so for years I have placed a thick velvet cover over those tiles when I'm listening.  It mellows out the sound, reduces hash, increases image focus.  But just recently I've tried leaving the cover off and I've really appreciated the added liveliness it brings to the sound.  The only issue is that tonality does take a little hit. 

So I'm going to order a curved diffusor and try that out, to see if I can keep some of the liveliness I'm enjoying, but restore a bit better tonality.

Thanks for the reply, prof
6.5' seems close for Thiels. Seems like most listeners prefer at least 8', so I'm surprised to read about your set-up. Sounstage's measurements of the CS2,4, however, were taken at 2 m (~6.5') and the frequency response was outstanding at that distance (as opposed to Stereophile's inadequate measurement at a mere 50"). I hope your diffusor gives that result you want!

Finally, a team of audio pros working with JLA f112's and Thiel CS3.7s chose 100 Hz in this example, 
Actually, these guys chose 80 Hz, not 100. It seems that 80 Hz is the default choice for crossover freq. Still, no harm trying other values.

As in my prev. post, it's interesting that Thiel says 80 and below, while Sound Doctor says 80 and above. Too bad we can't ask Jim his reasons.


I've always liked closer - takes out more of the room, tonality smoother, speakers soundstage/disappear more, etc.

More distance generally means tighter images, brighter more lively sound.  I play with both, but tend to end up trying to get a good mix with a closer seating.

One constant is that I almost always have the Thiels points almost straight ahead.  I don't like the more pinched, tonally brighter sound when they are toed in, and that goes for pretty much every speaker I buy.
Toeing out closer to straight ahead gives a bigger, more lush sound, where to my ears voices and instrument start to become more realistically life-sized.

BTW, one thing I've occasionally puzzled over is how the Thiel 3.7s seem to be just a tad more airy and resolving, despite the fact both speakers share the exact same coax/tweeter.  I recently watched a Thiel video introductions of the 3.7 and the 2.7 and noticed that in the 3.7 Jim made the point to that the 3.7s front baffle was made of inches thick aluminum.
But on the 2.7 video, the front baffle was only described a "3 inches thick" but aluminum wasn't mentioned.  So I think maybe the 2.7 uses maybe thick MDF or some other material to mount the drivers in, vs the aluminum in the 3.7s.  Perhaps that accounts for the slight difference I seem to perceive.
With Thiel closed,does that make our speakers more desirable,valuable?Kinda like Trans Ams did when Pontiac died?
Hello folks. I've been scanning this thread as time permits but life is short. By way of introduction, I was a founding partner and for the first 20 years was the director of manufacturing of Thiel Audio. I was intimately involved in all aspects of product development and company-building. I hope to contribute some elements of perspective to this conversation, especially where speculation lacks sufficient knowledge.

I want to clarify Jim's attitude about passive parts quality. From the beginning in the mid 1970s, we became very aware of the subtle but significant improvements via better parts. In fact we were an early innovator re film caps and bypassing with small values of better caps. We introduced long-crystal, six nines wire for our air-core inductors to the industry. I'll spare the details, but Thiel understood that landscape before it was considered an issue. So, the speculation that Jim was strictly a measurement-guy is incorrect. The reason for less-than-best caps is that they can be cost-prohibitive for highest value per cost engineering.Thiel was always about finding the optimum point on the cost-performance slope so that real music lovers could afford our products.

Regarding the measurement tells all idea, we found our way via intense, systematic, long-term music-listening and then Jim engineered solutions that had to also pass scientific rigor. Once the understanding about any particular issue was in place, the measurements contained the information; and the chosen solution was always closer to the scientific optimum. We could see the results of our work in the measurement data, but the converse was not true: the improvements could not be made predictively via the data. By the way, Jim designed and built test equipment that was way beyond what was being used for the purpose.

On the issue of hot-rodding existing Thiel products. I wholeheartedly recommend it, knowing the value / cost parameters of Thiel products. Rob hopes to offer upgrade services. Madisound is also a resource. I upgraded my (original 1989 prototype) CS2.2s with boutique signal-path caps. Wow. Keep in mind that the original caps were all carefully chosen for type, geometry and manufacturer and often bypassed by even higher grade capa. So, don't indiscriminately change everything. The best bang for your buck is in tweeter feeds. Note that (real) Thiel inductors are air-core (contrary to someone's post) and the wire is as good as it gets. Resistors are likewise selected to be very good. But improvement can be made there also. Solder is silver/tin, which requires more care than usual. Hookup wire is six nines with teflon jacket and proper twist density.

Another thread here has been the electrical vs acoustic first-order crossover. By "acoustic" Thiel simply means the net resultant system performance. That final slope of that driver in that cabinet with that insulation, wire lengths and other factors including eddy-currents, reflections, propagation distortions and other factors . . . all end up on a slope of 6 db per octave to produce a phase and time coherent crossover that passes a square wave and/or impulse - intact right through the crossover frequency. That fact of coherence allows the ear-brain to consider that signal as real rather than as puzzle to be interpreted in the fore-brain. I mention that because small system changes are more easily heard in a first-order system than in any other system. So, when you change caps, resistors and the like, be careful not to inadvertently change system parameters. As an example, some types of resistors exhibit different induction and capacitance than other types. Some capacitors exhibit different induction . . . and so forth . . . everything matters.

Take care with your upgrades and I believe you'll be amazed at the improvements in rendition of subtle detail.

To close, be assured that Rob is doing his best to ensure the best care of all you supporters who kept this little company producing these extraordinary products for all these years.

Best regards, Tom Thiel  
Wow!  Terrific information Tom!  Thanks so much.

As I've written, when I hear so many other speakers they still haven't seem to have caught up to what Jim achieved.  And it's wonderful that Rob's service will be available to us Thiel owners.  Now you have me pondering upgrading parts!

I understand if you don't have the time to answer any more questions, but just in case you do:

1.  As far as setting up the speakers to preserve the benefits of the time/phase coherence, as I understand it the coaxial driver design essentially solved the issue of listener distance, orientation; the coaxial signal will remain time/phase coherent if you are six feet or 12 feet away, slightly lower or higher than that driver in seating position.

The issue left would be the coherence with the other drivers, e.g. the woofer.  If one wants to preserve the time/phase coherence of all the drivers, it's the mix with the coax and woofer signal that suggests more care in listener orientation.  Would that be right?

I'm about 6  1/2 feet from my Thiel 2.7s and they certainly "sound like Thiel" from this distance, and as far as I can tell from stereophile measurements, I should also be realising coherence with the woofer as well, with my ears just below the coax.  Does this make sense?

2.  Subwoofer integration.  Some of us trying to integrate subwoofers worry that doing so takes apart some of the time/phase coherence of the system, insofar as a sub can't be placed right next to the main speakers and will therefore have a delay.  Phase can be achieved with the Thiel speaker, but the sub would be around a cycle behind in terms of time arrival.  I'm wondering about the likely effects of this on the time/phase coherence.  It seems to me one would at least be still getting the coherence in the midrange on up.  And if one were using, say, an 80 or 60Hz crossover point, the Thiel's woofer will still be playing part of the signal in time/phase.  I just wonder how much a subwoofer could cover this up, and whether that recommends a lower than usual crossover point for sub integration?

Outstanding! tomthiel

it is an honor to have you aboard. We all look forward in reading your thoughts and insights related to our beloved loudspeakers.

Kind Regards.

Happy Listening!

Thanks for joining this thread, Tom! My apologies for my role in incorrect speculation.

Thiel was always about finding the optimum point on the cost-performance slope so that real music lovers could afford our products.
I certainly appreciate this attitude. Thiel's top models were out of my budget, so I was glad to afford CS1.6 and, now, a used pair of CS2.4SE. Still, and I intend no offense, I've never had the impression that the CS3.7 and CS7.2 were a full-out attempt to deliver the ultimate in SQ. And, IMO, the area where these came up just a bit short was in the passive parts. As I've written elsewhere, it's also my opinion that your brother engineered some of the best drivers around. I suspect a tweaked CS3.7 or CS7,2 would sound pretty much as good as anything available.

I am stoked to read that Rob is planning upgrade service! Please make him aware of this thread. Thanks for taking the time to post.

Mr. Tom Thiel

please feel free to contribute as much commentary as your personal time/schedule allows. I am very interested in reading more about you and your Audio journey.  Equally important, discuss your favorite musical tastes.

Happy Listening!

I apologize in advance for what might be spotty participation. I travel and am highly involved in multiple projects.  But on the other hand, I do appreciate this forum and the enthusiastic involvement you folks have in the sport.

Regarding phase / time integration: An optimum axis exists where the drivers' acoustic centers are equidistant from the ear. Thiel designs for a 38" ear height as a seated average. Since the objective is a point source, the coaxial / coincident upper range driver obviates time arrival problems there. But the woofer is distant in order to place it on the sloped baffle at the proper distance from the average-height ear. The closer you get, distance error becomes more likely, but not necessarily so. (a three or more element system would have only one solution, but this 3-way with the coincident mid-tweeter makes it a 2-element system with multiple solutions.)  A measurement from your ear to the tweeter and the dust-cap of the woofer should be identical. If not, adjust your ear height  or speaker tilt accordingly. Pink noise is also a helpful tool in finding the sweet spot.

Subwoofer placement presents many problems; room mode minimization competes with other listening factors. A previous question about the "below 80Hz" crossover frequency is germane. The lower the frequency, the less the ear-brain specifies position. Bass waves are long, so bass is everywhere. However, the real-world crossover slope allows the subwoofer to contribute into the mid and upper bass where the ear-brain does specify position. I like Thiel's augment mode where the crossover to the woofer is first order and only the subwoofer is higher order. By the way, that is tuned as a 4th order Linkwitz-Riley. (Note: this stuff is from long-ago memory and I am not fact-checking as I write.)  I use a stereo pair of Thiel SmartSubs and place them at the proper ear distance for best integration and use the room-boundary controls to adjust for early wall reflections. I find the system amazingly accurate and effective and the result surpasses any other system of which I am aware. Keep in mind that when conventional subwoofer integration is employed, the frequency response at the listener position is optimized at the expense of all other positions in the room. Therefore the average power response in the room is wrong and the resultant sound is artificial. Remember that the ear-brain is synthetic, we create or fabricate the sound we are hearing and when the sound doesn't match the room, that is unsettling. Bass is especially subject to needing "psychoacoustic rightness" in order to be emotionally gratifying. Note, I realize I am skating into my personal research and conclusions with insufficient contextualization, but I want to get the concepts on the table for your edification.

Bottom line: I think that bass-generation position is very important and I position my subwoofers where they are distance-correct and let any room problems be addressed via Thiel's sophisticated distance controls or room treatment. Remember the magic of corner-positioned bass dumps. Pressure develops at the (normal) 8 corners of the room. Make holes / dumps there and room problems are drastically reduced. (Open a door or window, install a vent, and so forth.)

Regarding music: I was a singer-songwriter and recordist, which partially led to the formation of Thiel Audio. I prefer acoustic, authentic, ethnic-folk music with stellar production values. I appreciate all forms of music. I like live or live in the studio recordings and find the current multi-miced and processed amalgums to be generally uninvolving and unsatisfactory, no matter how well done. Our early research that led to our phase coherent products was validated by the high level of emotional connection to the music when played via a coherent solution as opposed to the normal, hi-fi, higher-order crossover solutions. Long story, short answer: Coherent Sources are perceived as real.

I presently design and build acoustic guitars with related research, teaching and mentoring. Tonewood creation and sales are also part of my offering. I am presently creating a high-resolution record-playback system to record and store sound samples of guitars under development for direct A-B comparison via selective playback exactly where recorded. Earthworks mics and preamps, yet unchosen ADA conversion, REAPER DAW on Mac, Classé DR-6 pre and pair of DR-9 power amps (hot-rodded) with Sennheiser HD800S open and Beyerdynamic 770 closed headphones, all six 9s solid wire configured in house. The recording rig will be used mobile and in this multi-purpose studio. We build guitars in the recording-listening space.

That's about all for now. Back to work.
Thanks very much again Tom.  Very timely information in my case, and much appreciated!
this is from Rob in response to an email i sent him.   he has been great to work with.

Thank you very much Kent!


The transition period for the changes are difficult and many. I definitely have a good stock of CS2.7/CS3.7 coaxial drivers if needed. My goals at THIEL are to continue providing excellent customer service for all THIEL Owners. I really do thank all Audiogon forums and customers for their continued support. Without you guys, I would not exist. Many Thanks!


Rob Gillum

THIEL Service


763 Newtown Pike, #130, Lexington KY 40511

Guys, the past few days have been an emotional roller coaster for us Thiel owners, but recent postings by Tom Thiel and reports from Rob Gillum are quite reassuring, to say the least. I would definitely be interested in hearing from anyone who has done any upgrading, especially with my models - CS3.6s or CS1.2s.
Thank You- Mr. Tom Thiel
no doubt that countless hours of research, testing and critical listening, led you and the Thiel team into each and every coherence -sourced loudspeaker. I will never forget my audition of the CS 2.4, the model that set my journey, in motion.
Happy Listening!
I'm thrilled to hear that their will be service for current Thiel owners.  The idea of getting upgraded crossovers also sounds great.  It would be a real upgrade for a reasonable price.  A pair of speakers that would be significantly better than my 3.7s would probably cost 30k or more and I might ultimately decide it wasn't an upgrade at all.

The question rolling around in the back of my head is whether there is anyone out there who might carry the brand forward?  Any possible successors?  Anybody interested in acquiring the name in order to continue Jim's work in any way?  

boutique signal-path caps
This strikes me as denigrating language, BTW. At best, it implies stylish or luxurious, having nothing to do with SQ. Probably I'm nit-picking but wouldn't it be more sensible to call them "audiophile-grade" or "high performance" instead?

  1. a business that serves a sophisticated or specialized clientele.


not at all. You may want to reach out and touch Dave Garretson
dgarretson here. He is our resident Clarity Cap OEM expert and can further advance the differences between OEM, SA and ESA film caps.

Happy Listening!
Yes, I’m just nit-picking.
1 a : a small shop dealing in fashionable clothing or accessories b : a small shop within a large department store
2 : a small company that offers highly specialized services or products
IMO, different word choice would have made it clear that Thiel thought the Clarity Caps improved SQ rather than imply a mere esoteric nod to neurotic audiophiles. Jim Thiel’s words in the UltraAudio interview were plenty clear regarding improved SQ but "boutique capacitor" as a bullet in a promotional brochure? Not so much. YMMV.

Regardless, I’m thoroughly enjoying my CS2.4SEs, boutique or not! I will contact Rob Gillum or Dave Garretson at some point and see about boutiquing them even more ;^)
a response from Rob Gillum to a question i had asked him

The CS3.7 cabinet is pressurized from the woofer and it is true that if there is an air leak between the main cabinet and the coax chamber, it will cause unwanted pressure to the coax midrange. This can cause the midrange driver excursion to be greater, which in turn will cause the midrange to fail. To check for the leak, you can gently push in on the woofer and Passive diaphragms at the same time. This will pressurize the cabinet, and no movement should come from the coax midrange. The midrange diaphragm is connected to the coil former via 25 points of a special adhesive. If the CS3.7 is driven hard, then it is possible for the glue joints to break. If only a few break, then the end result is distortion. If many of the glue joints break, then the excursion will become great enough for the lead wires to the mid to break. This will render a dead mid.

When sealing the coax chamber, use a caulk containing silicone. Door and window. There are two pieces of tubing which carry the wires into the chamber. Make sure that the wire tubing is not leaking as well. At the factory, we injected some hotmelt into the tubes to seal the wires. Also make sure that the tubing is not leaking around the holes in the divider.

In my limited experience with repairing Thiel 3.5 midranges a couple of years back the performance of Thiel in general warrants what is truly an “investment” as opposed to a mere “repair”.  Even with the $600 + dollars invested into a pair of speakers that cost me approximately the same,  (methinks) where could one spend $1200 on a pair of new speakers and get the performance/Sonics of Thiel?

We all know the answer to that question. 

I just sold off my pair of 3.6 to a fellow member who drove 250 miles to pick them up - amazing how Thiel fans are willing to spend the time and effort to get ‘em, ain’t it?  I drove an equivalent distance to pick up my first pair of 3.5’s. 
I drove an equivalent distance to pick up my first pair of 3.5’s.
I recall reading on audioasylum that Charles Hansen thought the 3.5s were Thiel's best sounding speaker with the 3.7s a close second. But maybe I'm hallucinating as I can't find that post now.
To check for the leak, you can gently push in on the woofer and Passive diaphragms at the same time.
I'm very reluctant to try this. Supposedly, dimpled drivers have no measurable or audible effects but . . .

Maybe you can use something with a bigger surface area than fingers yet still softish?
To check for the leak, you can gently push in on the woofer and Passive diaphragms at the same time.
I'm very reluctant to try this. Supposedly, dimpled drivers have no measurable or audible effects but . ..
To check for the leak, you press on the diaphragm, not the dustcap.

If I got this correct I think what I appreciated most from Tom Thiel was the speakers Jim made needed to make music sound real and not at the expense of accuracy. Accuracy certainly is in the mix because these speakers sound about as real as a speaker can reasonably get. Because of that I think they walk a fine line and when people get an unfavorable impression of them i think they have not be set up well.  I have never found them to be bright, lean, fat, tubby, warm, cold. They are about as spot on in the middle for me as a speaker can get. Makes them easy for me to season to taste. Better than most speakers I have had or heard. I think about it their tall order of mimicking a point source, phase and time coherence, a real live music presentation, well balanced tonally they kind of combine the best aspects of different types of speakers to a point it is not hard to get excited listening to music on them. Actually it is harder to control your excitement about these speakers. 
Thanks Tom for the suggestion for upgrading the tweeter/mid range caps. I am going to do that.
Accuracy certainly is in the mix because these speakers sound about as real as a speaker can reasonably get. Because of that I think they walk a fine line and when people get an unfavorable impression of them i think they have not be set up well. I have never found them to be bright, lean, fat, tubby, warm, cold. They are about as spot on in the middle for me as a speaker can get.
I completely agree. None of the Thiels I've heard (CS7.2, 3.7, 2.4, 1.6) sounded overly bright or cool to my ears (altho' the CS1.6 could be strident at high SPLs with certain female vocalists, I think this is related to the distortion at 1 KHz seen in soundstage's measurements).

Shane Buettner's review of the CS2.4 opined that the midrange had a "slightly-on-the-cool-side-of-neutral sound" compared his reference Vandersteens. But I've also heard the Vandersteen 7 (which is a SOTA-level speaker, IMO), 3A Sig, Treo, Quattro, and I lived with the 2Ce Sig II for 10 years. I have no idea what he meant. To my ears, the Thiel CS2.4SE sounds very neutral, resolved, open, and transparent through the midband. In fact, it sounds superbly balanced at all frequencies. When I listen to performers that I've seen live, I have no trouble whatsoever imagining that they are in front of me.

My conclusion is that people complaining about poor SQ from Thiels have only heard them poorly set-up or with poor-performing amps and/or sources.
I totally agree with amps and sources making a big difference!I like heavy metal bands and most of my favorites are not mixed well! My 3.7s do the best they can with what I feed them.Once in a while I’ll play a well recorded song and it’s a totally different speaker! I wish they would always sound like that!Somebody said that the 2.4’s are more punchy than the 3.7s and I agreed until I heard my 3.7’s with a class d amp with a high dampening factor(wow)!Blew me away!Thats the bass I wanted from day one! 
as a 35 year, four generation owner of the 2 series,  i would like to weigh in on the  "Thiel is bright" issue.   my first pair,  the cs 2's were bright but not offensive.  once i got the 2.2's that issue really became moot,  and by the time i got 2.4's,  no tipped up sound at all.  i do agree with the fact that these speakers will not be real forgiving with a bright sounding amp.  I have had my best results with the  PS Audio BHK 250 amp and the 2.7'.  a match made in audio heaven. 
Thiels I think have a true to life tonality in general, but their neutrality is  really nice blank slate that you can push in the direction you'd like.

I use tube amps to push them in the direction I like.

Tube Amp Owner Rejoice!


I would love to hear Thiels with tubes, that is something I have not had the pleasure of experiencing!

I have never had "bright" in my room with 3.6 or CS6. I even had my 3.6’s at one point hooked up with KCAG and KCTG IC’s, cables that are plenty generous in the upper octaves and it was not a bright presentation, clean yes, bright no....clean and transparent with outstanding dynamics.

I have always had tubes in the preamp stage and room treatments. A tube pre is a match made in heaven, but will always be curious about a tube amp. I wonder if one would push out Led Zepp II the way I like it!