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!

Showing 50 responses by tomthiel

That's the old site when Kathy sold to New Thiel. Those are the old phone numbers, and notice there are no dealers. Might be a spontaneous archival regurgitation.
Arvin - thanks for sharing. An old-school engineering audio tech informed me, after working on my Classe DR9s, that it shared essentially the same circuit as the ARC solid state amps. Who knew.
Regarding your room. Nice. This detail work I have been doing on Thiel Classics has underscored the vertical lobing problem. The problem is that phase angles and resultant amplitude irregularities get worse the farther off vertical axis one's ears are. The closer you get to the speakers, the more critical the geometry becomes. Nothing new. The target ear height is 90cm or 35-36" with the speakers flat on the floor. It seems that your ears might be high, sitting in that chair at close range. I have the same problem. I clamp a carpenter's square to the side of the cabinet with its top edge 90cm from the floor, and then tilt the cabinet until I can sight to my ear-height target in my listening chair. Sound and measurements get appreciably better.

Just a thought. Enjoy. Nice rig. Tom
Unsound - thank you very much for your links to PS reviews. I will certainly wait until I read reviews on their upcoming PerfectWave SACD player.

Furthermore, I have now read John Atkinson's technical review in AudioScience of the Stellar GainCell DAC/Pre that I own. Disappointing, to say the least. Thanks again.
Arvin - as we know it's a kettle of soup and everything interacts. Please keep us apprised of what you learn with the tilt experiment. 
I really like the Morrow cables compared with my admittedly limited stable of competitors.
solobone - I'm interested in your comparative evaluation against whatever else you use, as well as the Maestro rank in SW's line-up.
Hello all - back from away for a few days. Jon - was it you looking for grille fabric? Rob at Coherent Source Service has original grillecloth. Note that it got more sheer over time, so you might need a matched pair.

Re amps: What a trip - I have some potentially relevant experience with the AHB-2, Classe DR9 and Adcom GFA555 II. My setup includes 4 four pole knife switches plus locking bananas on their output jacks, driven by two pairs of amps, so that I can rig direct comparisons with simple switch throws and banana swaps. My test crossovers are outboard with no-solder access to separate driver outputs. Two CS2.2s are wired with two direct runs to each driver, swappable at the crossover outputs for comparing cable runs and the effects of cabling on the 3 different driving amps.
The GFA555 is a known to be decent mid-level amp. The DR9 performs above its price class. David Reich used Thiel CS3.5s as a design load. According to Atlantic Systems, the eastern US MacIntosh warranty service station, the DR9 output circuit is ’the same as’ the MacIntosh solid state circuit. Good amp. The AHB-2 is a THX licensed implementation of a class H amp regulated by a small Class A regulating circuit - new type of topology. I have appreciated discussion here of the AHB-2 among its peers. I agree with the observations that its bass leaves something to be desired. John Siau says that it is correct and "everything else" is bloated or loose or too big. That may be true. It is also true that B&W’s big bass would complement the AHB’s leaner than most bass balance. The AHB-2 is a winner, but might have deficiencies in the deep bass.

My test allows a CS2.2 woofer-only fed through a knife switch driven by the closely level-matched bridged DR9 or bridged AHB-2. The 2.2 crosspoint is 800 with first order rolloff, so there is musical content all the way up. Using a variety of sources, and with the absence of mid and highs, I consistently hear the following:

The AHB produces upper reaches which are cleaner, more detailed and more articulate. The lower reaches are drier, with the deepest transients sounding somewhat limp. The fundamental seems diminished. That diminishment might be in time-duration, but it sounds like transient imprecision and reduced level. Sounds like a hole in the bottom of the harmonic sequence.

One iteration of my test was with Dana Cunningham’s ’Live at Stone Mountain’ concert on a Yamaha concert grand, with Jeff Oster on horns and Max Dyer on Cello. I attended the stunning concert and assisted Dana’s evaluation of mixes and masters for production, so I feel comfortable with knowing the producers’ intentions. In this case as in general, I judge the DR9 to nail it much better than the AHB. The DR9 (bridged) delivers solid onset transients and well integrated fundamental bloom. I admit that the AHB reveals more nuance and space around the trumpet and cello. Similarly, the growl of the lower cello tones are authoritative with the DR9, and easily un-noticeable with the AHB.

Even if I accept Benchmark’s claim of ’rightness’, which is plausible given their company’s excellence, there remains the problem of the sonic jungle. Even for this live performance with minimal processing, the original musical event has gone through multiple stages of tweaking, and all of that tweaking used "normal" amplifiers with sonic signatures closer to (or actually being) the DR9 rather than the leaner, drier AHB.

Just for grins, my setup allows the following very appealing setup. The tweeter and midrange each has its own channel of the AHB. No contest winner over the GFA555 and noticeably more articulate and detailed than the DR9. The woofer can be instantaneously switched between a bridged DR vs bridged AHB. After all the note-taking and head scratching, I selected ’Flying over Water’, with Piano, Flugelhorn, Cello and Congas, for its beauty and complexity. Played full length with each bass amp, the DR9 always took me there and made me smile. The AHB left me in my chair analyzing the mix. Note the same result even with the SmartSub engaged; the sub-bass didn’t supply enough bottom for satisfaction.
I guess that’s my report for today.
tmsdrg - I am one of the culprits of touting the necessity to double power with halving impedance. My point was more academic than of real consequencel. If an amp doesn't double its power into half impedance, then it is by definition current limited. BUT, as has been pointed out here previously, that point of art is of no real importance as long as there is enough current to deliver to the load. So, doubling is not a technical necessity to drive Thiels, but that sense of anemic bass, slow transients, etc. is symptomatic of running out of current capacity. The 3.7 is about twice the efficiency as many previous Thiels, so the problem becomes less of an issue than before.
thoft - sit tight for some first-hand experience here.For my part, I tested the Madisound "drop in" and it is so different that I would never consider it. Anybody want to comment?
The tweeter you want is the rebuild of that particular version of the Dynaudio D28.

Regarding woofers, that was highly specialized. I think Rob Gillum at Coherent Source Service can rebuild yours. I haven't heard of anything else that works.
Remember that these drivers each cover a huge range and the various contouring circuits are specifically tuned to the resonances and anomalies of a particular driver. Generic replacements just don't work. But take courage, we will eventually have a stellar solution for you.

Comments please.
Jafant - remember, I'm not an engineer; my experience is more as an observer - user. Slew rate still gets lots of attention in professional audio, especially microphones and their preamps, but it doesn't show up much in print. I have Tom Jung's original Studio Technologies Mic Pre which was reworked by Jim Williams (pro geek guru) to upgrade caps, etc. He increased the slew rate by 5x as part of his magic. The preamp improved its transparency substantially, but lots of things were done at the same time, so I can't attribute any specifics. I wonder out-loud whether slew rate gets less attention now because it is generally faster now than in the old days. Also, I can only speculate as to Power vs Pre amp importance, but I suspect SR is important everywhere equally. Some amps like Spectral place storage caps right next to the output transistors to increase slew rate substantially by purely geographical means.

My observations over the years includes SR being a major factor in transient performance and therefore detail retrieval.
Silvanik - thanks for the report. There is definitely real stuff going on regarding floor coupling. Our initial insight (before spikes were a thing), regarded the recoil effect, how the cabinet swayed caused mostly by the woofer recoil. That motion is large in reference to tweeter wavelengths and causes time smear which is audible in a time-coherent system. But the actual coupling only became noticeable when we moved from the farmhouse to the real factory with concrete floors. The presentation got much drier and lean in the mid-bass. The farmhouse floor was resonating very nicely - I much preferred the musical presentation on the wood joist floor.

Whatever you're doing, keep it up and let us know any further developments.
Yes, Jim was an armchair electronics designer and enjoyed talking circuits with Nelson Pass, Dan D'Agostino, the Bryston Boys and others. He constantly pushed them for better transient performance, current delivery, etc. from their amps. Originally Thiel Audio fantasized making the whole chain: speakers (powered), preamps and turntables. We started before digital. It became quickly clear that we had more than our hands full with the passive speaker link in the chain.

sdecker- when Jim developed the equalizer, that transient burst factor became obviously clear. He determined that an amp needed to deliver triple its continuous output for about 250ms to properly cope with a broad variety of music. He used that assumption when boosting the bass with EQ to take advantage of power that would, on average, be available in the bass. That assumption proved to be problematic in that many amplifiers, especially spec-driven designs, fell apart when asked to deliver transients while delivering augmented loads to the equalized bass. Some amps do a wonderful job in the series 1 and 3 equalized bass. But others don't, and sound bad, and burn out tweeters.
Our early amps included Phase Linear 400 and Threshold S500, which turned out to be non-representative, leading to an error of judgement.
I think the way Jim looked at it was that the tripling at 1kHz allowed for midrange transients beyond rated continuous power and that those peaks rarely coincide with bass transients, therefore the working headroom.

Error, or hindsight, or fudged specs, the EQ gave Thiel some notoriety in the amp department. I don't think Jim ever got the amp demand part right (from a market viewpoint). If his design loads maintained 4 ohms minimum, the speakers would be so much easier to drive and the voltage sensitivity and current demands would be in sweeter equilibrium. That's my layman's opinion from the user peanut gallery.
My packed unit weighs 70#, which kicks in additional overweight charges. And the risk is high. And hand delivery sounds like fun since I'll be in the neighborhood.
TATweak - I hope you find it!Thoft- Thiel serial numbers start at #1 per model (imagine that).The first 200 woofers were impacted. You can't fix the existing moving system, but Rob could replace the moving system and you would have a rebuilt driver for spare.
Fitter - I got the chance to compare CS7s with 7.2s when I visited Rob G at CSS last Thanksgiving. What a treat! I judge the 7.2 to be more concise / articulate, but he and I both liked the 7s better, as more easily listenable on more material. The main and possibly only difference is the mid drivers. The 7 has flat-front cast styrene pistons and the 7.2 has cones (of unknown to me technology). The flat launch plane eliminates whatever cavity effect the conical pistons might produce. They are both extraordinary speakers that I wouldn't mind owning with the proper room to do them justice.
Unsound - thanks for your response. Keep it coming. First, please let me explain my choice of words. By ’more accurate’ I mean adhering to a flat frequency and phase response curve. By ’more mature’ I mean embodying next-level technologies such as more sophisticated driver motors and diaphragms. I assume that I have considerably less actual experience with these models than you do, and that my opinion is therefore of limited scope and depth. In my present work, each model sample that I get, I measure and photograph and document and audition. For the 3.6 that means I have spent about one day with them. Period. Their introduction came near the end of my time at Thiel Audio and, frankly, I never found a subsequent opportunity to hear them. I concur with your disappointment - my opinion based not on performance (of which I am quite naive), but on philosophy. I don’t think ’rushed to market’ quite captures their introduction because Jim was always technically thorough in his development process. (often to the consternation of marketing director Kathy Gornik.) I think ’compromised’ might better capture it for me. My (ineffective) resistance of reflex bass revolved around trueness to our central principle of phase coherence. Jim and I shared the opinion that the bass establishes the musical foundation on which all else builds and that reflex bass is a compromise (permissible for budget.) But the model 3 was all about performance. Kathy felt that such details must be subservient to the demands of the marketplace (as you posit.)

Let’s shift gears to your ghost of a 4-way CS4 - exactly right in my view. Here’s what happened. It’s hard to understate the role that market demand places on a small growth company. Capitalization plays a big role also. Thiel was always undercapitalized - we pulled everything out of our collective hats, barely paid ourselves, rarely carried any debt and sunk our thin margins into self-bootstrapped growth. Enter the gravy years of the mid 80s. Affluence abounded. Many companies introduced their mega-priced statement products. Thiel was comparatively plodding along its incremental learning/growth curve. It may not be obvious, but Thiel succeeded better in foreign markets than here at home; we competed better in export markets at 2-3 times US retail prices. We were a big hit in Japan which at the time defined and led the pan Asian market. Japan demanded a Statement Thiel product. Jim floated some concept sketches with our Japanese distributor. Jim wanted to make your CS4. It made sense from everybody’s vantage point (from mine in Spades), except our Japanese distributor, who wanted what became the CS5. This next part is almost embarrassing, but what’s a little embarrassment among friends. Let’s talk culture. Our success in Japan was unusual, practically unprecedented, due in great part to our distributor. Kathy was adept at choosing optimal allies. Japan is a power-based culture and the contenders were brokering power arrangements where we held the weaker hand. A new distributor emerged with a Japanese-American principal, who understood both cultures and could navigate many pitfalls. He helped us navigate the weirdness of the number ’4’ in the orient. It symbolizes cosmic unluckiness, curse, death - bad suss. A CS4 would fail regardless of its merit. Kathy deferred to his guidance, but Jim would not put a CS5 moniker on a CS4 chassis. So he engineered the CS5, which in practical terms was beyond our company’s 1988 capacity to develop and produce. Tons of internal stress. The CS5 needed a longer incubation and internal design and engineering resources than the market demands allowed. It consumed the oxygen in our ecosystem which set the stage for scaling back the vision for the 3.6.

Now, that’s a lot of words for an internet forum. But you guys are my audience for these vanishing quirks of history.
The Thiel story contains lots of such workings behind the curtain, as do most human enterprises. It may interest you that the abandonment of the CS4 that you cite stands as a major element of my departure from the company I had co-founded and dedicated two decades to developing. In the early 90s, Thiel, like everyone else, faced an existential decision of how to survive in a market where multi-channel / home-theater was taking over. Thiel took that route. Imagine an alternative reality with a CS4 and a CS3.6 with a bass more true to its model 3 beginnings. Just thinking.

I was told that its coax would have had smaller drivers than the 3.7, suitable for crossing to smaller diameter lower midranges such as in the model 7; and would have trickled down to his 2.7 instead of the 3.7 coax.
I find this question re "opposite of Thiel" to be a good one. It demonstrates how individual the pursuit is. Each designer / company brings their own values, perspectives, resources and vision to the task. And both the task and its historic and cultural contexts are sufficiently large and complex to allow huge variability of outcomes. Thiel was a tiny player, which may have helped it remain true to its calling, which was to produce and support Jim's vision of a thoroughly accurate transducer, equally honoring all musically relevant aspects - augmented by the contributions of the other founders.

I didn't notice Bose on the list. Even if nothing is truly an opposite, I think it fair to remember that Bose was greatly responsible for the emergence of high end, especially brick and mortar demonstration stores. Most of the operators I knew in the day cited Bose as their focus for entering the arena, with phrases like "there must be better than Bose" , "Bose doesn't cut it", "Hard to believe people think they want Bose" etc. The upstart young designers resented that the large majority of Bose's budget went to advertising and marketing rather than product development and other oddities of Bose's dominance.

A personal piece of history: Bose made Thiel cease and desist from using the number 2.2 for our second generation model 2, which we renamed the CS2 2, without the decimal point, garnering more publicity and support than any emerging company could ask for. I found it amusing in the 2000s after moving near Boston and knowing some guys who worked for Bose, that they used the Thiel CS3.5 as their laboratory reference standard for product development benchmarking. Now, isn't irony sweet?

The original Phase Linear amps from the 1970s were nick-named "Flames Linear". We had one. It did.

Expansive grout is a waterproof cement product with adhesives, designed to expand in a crack to seal it. It may be called foundation crack sealer, wet-stop or similar.
Those original CS7 baffles were portland cement concrete, which continues to shrink over time. (Its first cure cycle is 7 years, when its shrinkage is nearly over.) Grouts add gypsum and/or other expansive masonry ingredients to achieve various controlled expansions. I don't know what exact product Thiel (or the nearby repair shop) used. But a millwright or masonry contractor should point you in the right direction.    Disclaimer: After my time at Thiel
Jon - I haven't been able to determine how many VPs were sold. The closest I get is a "few thousand pairs" of all the Power Products combined (using that coaxial driver). But, that may also be incorrect.

Painted with a broad brush, it seems that as brick and mortar demonstrating dealers declined and on-line and other sales channels took over, Thiel's sales per product and solid user experience also declined. Thiel had relied on high-quality dealers to select and manage appropriate customers, who often remained satisfied and committed over the long term. It seems that pattern may have eroded over time.
Prof, and other 02 guys - here's a little report from fun in the trenches. I picked up a single SCS4 this week, and have some PowerPoints and 02s in the hotrod garage. I set up a 4-way comparison with those models plus a CS2.2 for reference. I both listened and measured. What I learned is that not only was the 02 a very good little speaker, but that it holds its own very well against the others. Since I have 4 02s, I'm upgrading a pair for giggles and grins and learning.

The SCS4 is the 4th generation of the coincident driver, but is actually the 5th generation of the 6.5" 2-way. The crossovers are the same topology - 2nd order / positive polarity with the (high-pass / low-pass) crosspoints separated to eliminate the classic 3dB hump rather than inverting polarity as B&W, Wilson, et al do. The frequency and phase response measurements are very good, as good as the SCS4. The motivation for the coincident driver was because anybody could place a bookshelf speaker in any position or orientation. But on the proper axis the 02 is as coherent as the SCS. BTW, that topology is also employed in the passive coincident drivers in the 2.4, etc.
Robert - In the early days we used a lot of pop as tweak references. Heart / Dreamboat Annie along with Joan Baez / Diamonds and Rust were a couple that we wore out the record - before digital. I’ll also be adding some Cardas to my mix via DIY. Thanks for your report.
Robert - you inspired me to double my speaker runs to check results. I use Morrow SP4 with equivalent AWG of 14 ga / positive or negative with 8' runs. Nice improvement not only in tighter, better articulated bass (as anticipated), but as you say, across the board clarity and outside the box dimensionality. What was the equivalent AWG of your previous Cardas Neutral Reference?
Arvin - thanks for your detailed report. I would like to add some thoughts because setup is so crucial for performance. It's no secret that Thiels, especially the pre-coax models are tricky devils to optimize. I'll describe Jim's design assumptions, since working toward those ideals, within your own constraints, will result in the closest approach to objective correctness. Anyone's preferences may vary. All considered, I like a more far-field perspective; some like to be on the performance stage, and the room size dictates so much.

The design distance is 10' from speaker to ear (mic) at about 20° off axis - speaker straight ahead yields that angle. That setup takes a pretty big room and/or some sort of absorption at the side wall reflection point. Ear height is assumed at 3' (normal couch / easy chair). The farther afield, the more leniency develops for all geometry. Distance to backing wall is user selectable. I like about 4', which gains greater bass articulation at the expense of less bass amplitude.

Over the  years, I have seen the most grief caused by too-high ear position. 3' is the target, which gets more critical as distance decreases. Closer than about 8' and the relationships really suffer. Note that ear height adjustment works better than speaker tilting, since tilting changes the way the floor bounce works. I suggest getting ear height as close as possible, then tinting so that the tweeter (3' up) fires at your ear, and toeing in to control wall bounce while keeping the speakers firing at 10° to 20° off axis - they will cross behind your head.

All speakers deal with the room puzzle, but Thiel adds the challenges of lobing to the equation.
Robert - there are many variables in wire including gauge, purity, surface smoothness, dialectrics, layout, etc. To some degree, enough size is enough and the other design parameters become more important. Cardas knows a lot. Regarding internal wire: my point was that XO to driver resistance change will have more effect on tonality than pre XO runs. In fact, the differences will be pretty negligible and the other considerations may tip the balance in favor of "better" wire.

Norah Jones rocks. Little slice of history. The late Bob Lundvall found and signed Norah to his Blue Note label. I was working with his son Kurt who has his own audiophile recording and mastering business. Bob asked Kurt to critique the master of Come Away with Me, for which one of his references was my Thiel CS2.2s. I imagine that Kurt's evaluation notes probably had some influence on the final master. I love the recording.

Tmsrdg - I don't have 3.7s, but there is some baffle flat. My 1.6s benefited from laminar launch baffle treatment.
Arvin - floor coupling is, in my experience, a worthwhile endeavor. During development of the 03 In the late 70s, we discovered a new problem attributable to phase/time coherence, of a bothersome upper midrange jitteriness. A cure was to couple the speakers to the wood floor via 3 pins. That solution became part of the product and rubbed off into the general 3rd party stabilizer feet solution. Piercing carpet via spikes also firmed up the bass. However, coupling directly to concrete sometimes produced an undesirable edginess. In my time at Thiel, we supplied invertible pins where the domed end could be used to concentrate the load, significantly smush the carpet, but not penetrate to the underlying floor. A similar effect could be gotten by placing the spikes into small diameter cups of some kind. In the day I had some cups machined from brass (for shows). The top had a pointed-bottom hole to match the pin, and the bottom was a hemisphere about 1/4" diameter.  You can buy online brass hemispheres and drill a dimple to capture the point of the pin.
bonedog - in speakers white is plus. The other may be tan, which is minus. I recommend you test with a battery: D cell or 6v lantern. Momentary contact only. Plus makes the driver move forward. You can see the woofer and feel the tweeter.
Rob - yes I have and yes I would like to. I believe Thiel Audio represents a brief place in time when small-scale upstart enterprises were possible and appreciated. I have been collecting material and hope someday to have the time to pursue it. I've been forthcoming here, but that just scratches the surface. It was a very wild ride.
Cascade - I can't remember his or his shop's name, but I remember playing the first-tier Thiel speakers for him in his shop in 1977. He was complimentary and said he wished he were younger because a new world was unfolding for the young. He showed me his reflective speakers, which pre-dated Bose by many years. Bose had threatened him (cease and desist) and he responded that he would not sue to invalidate Bose's patent if Bose left him alone. And so it was.
Arvin - what a delightful lyrical moment to share, when things are 'just right'. Since such moments are so rare, I would appreciate, as might others, knowing the particulars of your rig, your room, and your reflections about how you arrived at this lovely place.
Hey guys - I would like to share a link that my daughter Dawn sent me for these times of darkness. Music feeds the soul.
Arvin - thanks for sharing your synopsis. I'm curious how you landed on 30 - 32" seat height.
George - I had hoped you had gotten relief by now! I presently, since December, am struggling with similar symptoms. Reducing electromagnetic fields, especially microwave from wi-fi router and smart electric meter have helped. Brain electro-chemistry is wonderful when it works.
Shubert - Yes Dawn is wonderful. You may have "met" her virtually as Thiel's international sales manager from mid 90s to 2013 collapse.Masi- consider trying to stabilize the speaker on the stand. Three coins (back corners and front middle) serves to unitize the speaker with the base. Please report back. Also, small wire gauge can smear the bass. 
Arvin - FWIW, the design ear height is 3' and distance 10'. Closer than 10' means greater sensitivity to height. But, some folks prefer the more mellow presentation of lower listening heights.
Rob - please remind me what model speakers you have. The separation that you are describing was, in my day, standard practice. We always separated the twisted pairs to reduce capacitive coupling of the wire runs. Has anyone else noticed whether their runs were parallel or separated? I would like to figure out what's going on.
Rob - that sounds like someone replaced your original wire. Thiel wire was unmarked Straightwire (oxygen-free, 3 twists / inch, teflon jacket,etc.) . Did you buy the speakers second hand?
Rob - I can only speculate. Rob Gillum would know if your wiring was stock or not, since all the 2.7s were built by him in Lexington. I suggest that you query Rob and report back to us what you learn.
Andy - the baffle angles are similar because the design parameters are similar. But each takes its own particulars into consideration and yields a slightly different resultant angle. Notice that some models have slight wave-guides which differ from one driver and model to another, determined by target radiation pattern to equalize power response through the crossover. Also, distance between drivers makes a difference. Bottom line is whatever angle produces co-temporaneous arrival time at the design target (about 10' out x 3'up x 10° off axis). The CS2.2 has about 11° baffle tilt, others more and less.
Rob - I have also been unsuccessful contacting Rob G. Perhaps he'll re-emerge when the virus weakens. Re bankruptcy: I am in contact with the court, which seems to operate on Tennessee Time.
Unsound - you're right. Tennessee is decidedly the South, where things can move pretty slowly. Kentucky is "a place betwixt and between", with elements of many cultures and none in predominance. Lexington feels like a small cosmopolitan city, whereas Nashville feels like a southern town driven by country music.
Reubent - a general note: The 2.3 was the first generation of the passive coax. That coax and the woofer were bettered by the 2.4. But the crossover topologies are the same, and many of the values are same or similar. Eventual performance upgrades will apply to both models, and 2.4 drivers should become retrofittable to 2.3s with appropriate XO changes.
Andy - thanks for the article. I would mention that some of the statements are broad enough in nature that they don't apply to any specific loudspeaker in its use conditions. Of course, I mean Thiel. Toole's statement that off axis (vertical and horizontal) integration always suffers (paraphrase) is such a statement. Indeed it is true. But it is also true that a Thiel speaker 30° or 60° off axis is linear in both phase and amplitude. It is clearly true that the 1st order vertical axis lobing requires a single vertical listening position, ear height 3' up at 8' plus distance. But the up-tilting driver orientation and the resultant off-axis listening axis serve to create an average in-room phase and amplitude power response that is quite respectable, often bettering non-aligned counterparts.

As to the obvious dynamic range limitations due to large driver excursions - granted. First order slopes don't work well for stadium coverage or high-amplitude monitors. Driver overload is the Achilles Heel that we constantly fought and gradually improved. Drivers burn out or fatigue when asked to cover large frequency bands. But for livingroom hi fi, Thiel developed drivers that did well enough.

Despite the claim of near or no audibility of phase correctness in real playback rooms, Thiel demonstrated it over a long period of years to our complete satisfaction that phase coherence was audible enough to merit tackling all the hassles that came with it. And for some jujitsu, phase coherence made other anomalies much more obvious, requiring solutions to problems that would have remained invisible in normal phase-compromised systems.
Thanks for mentioning that. Those studies assume that anything that is scrambled can be descrambled with no deleterious artifacts. Part of my profession has been pointing out those "inaudible problems" in mixes and masters. I and my clients can hear the difference between a correct, unaltered take, vs one that has been "linearized", etc.

You know, a big part of the demise of "New Thiel" was that they chose to believe Toole, et al rather than construct their own comparisons. I offered to participate in those comparisons, and they said "no thanks"; they said knew what they were doing.
I agree about the 'special sound', as we have discussed here. My take focuses on the brain power that is freed up by not having to descramble the phase errors in other systems. I find the difference significant as do some others. "The Industry" (Toole et al) dismiss it in various ways as trivial.

I know for certain that many amp, cable and source practitioners and critics use Thiel as a tool to "see into" the source chain. I find that significant.
Nuzzi - I’m having a memory lapse even though it's only been 37 years. Please tell me if your CS3 equalizer is in a wood or metal case.
Andy - it's good to point out not only the article's conclusion, but also other aspects such as why are they doing it, and what is significant to whom. As a whole, the professional community thinks that wire doesn't matter. Audiophile sensibilities and nuances are often not on their radar. If a factor doesn't hold up to ABX scrutiny, they dismiss it out of hand. I have developed a neurological model showing how ABX is irrelevant to nuance. And many top-drawer pro audio practitioners know that they must "live with" a component or solution for a week or two in order to "get it". That's a different world than ABX, where a snap judgement is made regarding whether X matches A or B. It is their gold standard, but I believe it is testing the judgement priorities of the subject rather than the subtle, complex merits of a component or solution.
sdl4 - Thank you. As you know, our undertaking was more heart and soul than the standard business model. We took pride in how long people used our speakers, sometimes for generations. Subtlety and nuance was a requirement, not a nicety.

I agree with your ABX comments and can add a couple more. You are not alone in "shutting down". I believe the judgement process is not only nearly impossible with the auditory chain, but actually misleading. I believe that several key factors are overlooked in the ABX model. Central among them is that the auditory processing response is closely linked to fight-flight / survival. We must immediately recognize the size, shape, weight, direction and speed of whatever made that noise in the woods. Sound is wired globally in our being. As such, the cognitive analysis of the sound is specifically shut down, especially in the right ear. Analysis is a luxury that the primal being can’t afford. So by applying ABX analysis and judgement, we are trying to short-circuit our primal experience of the sound (music).

I believe that the global direct experience in fact contains the information that we need as designers and want as music listeners - connection to the stream of energy. I still use a refinement of the evaluation process we developed in the 1970s at Thiel Audio. Here goes a story demonstration:
Some of you might remember Natasha, my young friend who listens to bats talk. Tasha happily has found love and moved out of town, which is great news for all concerned. But my ageing ears still want help. Good news is that I have found Marina Harris, a young singer-songwriter musician with outstanding natural hearing abilities. She is taking well to learning and relishing the listening that Tasha left behind. We have had two productive sessions, which served to underscore a very important element. That is Trust. Until she became secure that I was not "pulling a fast one" by repeating the musical segment with the same conditions, she was somewhat shy about proffering her opinions, and indeed could not really form them well. Once we established and she believed that I would always tell her the truth, and there would be no "fast ones", then she leaned into the task.
The procol goes like this:
Describe and agree on the protocol.
No idea what we’re testing for.
Play A while taking listening notes.Play B while taking listening notes(B has advantage of second hearing of same cut).Play an agreed part or all of A again - taking notes.Play same selection of B again - taking notes.Compare notes and discuss.Describe and discuss what we are testing for, such as doubling up the speaker cables, swapping an interconnect, speaker iterations, etc. including some description / speculation about how our notes relate to the systems under test.Then, armed with this experience and learning:Repeat A / B, A / B and discuss again.
Note that by design at no time is a commitment required, and at no time can the listener be "caught out". ABXers consider that a cop-out. I consider it a necessity and my experience is that a valid session is always (and must be) replicable after scrambling A and B double blind. In other words, a third party can re-assign channels and substitute different audition material before the subsequent validation test.

This protocol produces a wealth of information from many aspects including, technical, performance, emotional, memory/evocative, etc. I use it in evaluating recording sessions, mixes and masters as well as equipment and rooms. It makes ABX seem thin and poor.

As a historical note, in the early 80s, when developing the CS3, we had developed a relationship with the University of Kentucky. They were willing to collaborate with us using medical, music and engineering students, if we were willing to use the ABX protocol. We did some trial runs, which served only to muddy the waters, and provided little if any productive information. Therefore, we opted out. I am convinced that if we had gone down their path, we would have ceased refining our multi-faceted development process. Plus we didn't have the time to indulge their ABX plan unless it provided valuable information for us, which it did not.

I hope you’re all enjoying your opportunity for seclusion. I’m getting more time in the studio since the phone stopped ringing.Tom