Thiel Owners

jm - FuzzMeasure is similar to Room Equalizer Wizzard. It seems that REW has many more adherents in hi fi land. I got FM because JA used it extensively in his Stereophile graphs, and it works well for my semi-pro room optimization work in recording sites, studios and theaters.
FWIW: I've been working on my CS2.2s, because I have them, as my main workhorse to develop upgrade paths for some classic Thiel models. Everything learned will apply to the CS2. So if you love yours, you might keep them and see what we can eventually make of them.

JM - I'll chip in with a personal anecdote. When the Classe DR6 /DR9 setup was new, Thiel used it in demos with a pair of bridged DR9s. I still have and use those amps. The Classe replaced Threshold 800s. Thiel outgrew the Classe sonically and went to Mark Levinson and then Krell, with Bryston in the mix for our lower cost products. Although we didn't use Pass officially, Jim and Nelson held mutual respect and Nelson used some Thiels as development test loads. I have not heard the 250.8, but would expect it to considerably outclass the Classe.
All that said, I am still amazed by how much more improvement can be attained by solving room issues. In fact, many or most of my niggles with amps, cables and recordings have evaporated after running down and fixing room issues with FuzzMeasure and trial and error.  

JA - I posit that all Thiel models have benefited from toe-in for a high majority of users, including myself. But, it's a mixed bag of trade-offs and that toe in contributes toward the felt need to reduce high frequency energy. I'm unraveling the puzzle.

I'll note behind the curtain that Jim was smoking before he was a teenager and his high frequency hearing was compromised. Whereas his analytical ear was highly developed in sorting out the sonic integration puzzle in the lower ranges, he was comparatively insensitive to such nuances at the upper end of the sonic spectrum.

JA - thanks for the B&W lead. I haven't heard a B&W since 1995. They certainly have advanced the state of the art.

In Thiel history, B&W was a significant player. Being an imported product, they were at a pricing disadvantage, and having such luxurious designs and presentation, they appealed to upmarket customers. Thiel's niche was to surprise the more frugal customer with how much sonic goodness could be gotten from Thiel at a fraction of the price.

But B&W certainly deserves kudos for what it produces.

Snbeall - I’m not very expert, but I have some experience with the SmartSub which I’m happy to share. I was involved with the early development efforts with Berger, the lead engineer at Vifa. We co-developed the Class D amp at its core in the early 90s with lots of trouble and headaches. We persisted to produce our first powered subwoofer in 1997. As time went on, Jim added his patented room boundary compensation circuitry and voice coil thermistor compensation to counteract thermal compression. I was not in the equation after 1996, but I tried to register my opinion to Jim to allow user control of volume. But, as always, Jim’s MO was to make it "right" period, which in his book is flat anechoic with no user interference allowed. I’m not conversant regarding the SS technicalities, but it is theoretically possible to increase gain in the SS amp, (which I would love to do.) In the absence of schematics, I have tried, but found no one to reverse engineer the unit for either repair or such a volume adjustment mod. But, developments with the Thiel Audio IP rights may change that landscape. Stay tuned.
Regarding your LFE solution. It gets you volume adjustment, but bypasses all of the room boundary compensation circuitry. I haven’t tried it, but am told that LFE is far less musical and more room interaction interdependent. My own room suffers from needing more bass than the SS delivers, which is a common complaint. I recommend trying your hand at tricking it to thinking it is farther out in the room than it is, which will increase its output relative to its real location closer to the reinforcing boundaries. In my particular case, the SS is at a side wall about 5’ from the front wall, but I set the controls at 1’ from the side wall and 3’ from the front (some iterations are in metric equivalents.) When my installation got way better is when I set the SS2 through the wall with the baffle flush, while leaving the controls set as before. I use FuzzMeasure in my work, and FM shows this installation to be flat in this room to about 15Hz. It sounds very good. Maximum reinforcement would be from the floor/corner position, which in many rooms would stimulate maximum eigenmodes, but is not possible for my particular room (see previous descriptions) even though it is quite free from those modal problems. The point is that you can play with actual vs dialed position to get more bass from the SS.

Feel free with any questions, and let us know how your experimentation progresses.
Tom

Tmsrdg - my knowledge of the SI-1 Integrator is all hearsay from the same sources and reviews as you have. I might add a little more: that Jim and later operatives after his death tried unsuccessfully to develop a troubleshoot-repair operation. Jim was a master intuitive repairman - he could troubleshoot most any circuit in a few minutes and fix it. I don't know what level of effort was put into solving the repair need for the various electronic compontnts. Short answer is that I know very little about the SI situation in particular, but that in general I am working toward a comprehensive repair solution.

Todd - the PXO creates an actual designed crossover with the 3.7 etc for a seamless transition. I find it inaudible. Rob may have it. Or if you find any PXO, he can reconfigure for the 3.7 etc

Todd - sorry, I meant B. I find the SS solution to be a seamless integration between sub-bass and upper frequencies. There is also a little of A in there: It just sounds like bass, not like a subwoofer and therefore doesn't draw attention to itself. 

JA - I can't say that I know SW's current catalog. I have mid-level SW and consider it a strong performer for its cost. Their offerings top to bottom make sense to me, but I haven't heard their newer or pricier models. Most of my exposure to the breadth of what's out there comes from you guys here.

coop_301 -  Last year I spent considerable time selecting my front end. My particular bias is toward neutrality / honesty with stellar technical specs required and extra points for ubiquity in the pro record-making world. I landed on Benchmark. I chose their stand-alone DAC-B over their Hybrid Gain Control because separating the digital DAC from the all-analog preamp fits my needs better. You might enjoy adding it to your list.

 

JM and all - for a dose of Christmas Music with a twist, tune into Dana Cunningham's Christmas Concert, Sunday night at 8PM eastern via her website danacunningham.com  It's my first livestream event and I'll be recording it in high resolution audio for (hopefully) future audiophile mastering. Dana's piano journeys are quite a trip. This trip begins in an unfinished restoration of an old-school theater that was gutted by fire several years back and is being brought back to life as a teaching / performing music school / venue. This is the first concert from the bare stage.

Read deeper re output voltage. I think it has 3 levels, setable via internal jumpers. Benchmark is very attuned to gain-staging. Their power amp has 3 input levels.

dsper - if you like the Thiel sound, a pair of CS.5s might work. They are a diminutive floor-standing 2-way which under your conditions might work well - Stereophile tested them at 89dB sensitivity. Thiel's flat impedance curve works to your advantage and I find them very easy to make sound quite good.

https://www.stereophile.com/floorloudspeakers/223/index.html

jafant - your audio interest is immense! I, on the other hand, have very little experience outside the realm of Thiel. I believe that some day you might become a candidate for an enhanced CS2.4. 

Thielrules - thank you for posting that amp list. There is a fairly widespread belief among audio pros that audiophiles prefer distortion to provide qualities they call "fullness, richness, lushness, warmth", etc. I must confess that it took me quite some time living with the Benchmark AHB-2 to appreciate its lean directness as being correct. I now delight in its simple clarity and hear other amps as adding artifacts. 
I am using a PS Stellar Gain Cell DAC/Pre. It's nice, but PS gear lands pretty far down the list. I am coveting a listen to the Benchmark DAC/Pre. Is there a similar list of preamps?

Beetle - how did that Halcro amp weather the ages? Its circuit topology seems reminiscent of the BM AHB-2 in layman's descriptive terms.

Indeed specs don't tell the whole story and harmonic distortion can be a particularly beast since low / even harmonics sound sweet and odd and highers sound non-musical.

I've never heard better.

 

And another one bites the dust. And another one rises before us. Sing that song loud and clear. Happy New Year.

JCHussey- I would like to address your CS3s. This model is the de-facto watershed that put Thiel on a solid road to success. The CS3.5 gets more respect, but it is essentially the same speaker with a better midrange driver.

Taken together, the CS3/3.5 were designed before we adopted CNC machining, so more of the cabinet stiffness is in the walls with far fewer braces. The woofer and tweeter are the same and the cabinets have the same volume. Only the baffle angle is a little different due to different midrange acoustic centers and bringing the upper drivers closer together.

The CS3 & 3.5 are fraternal twins; any upgrades developed for those products will apply to both.

The sculpted baffle is a sharp point of Thiel history, and arguably responsible for Thiel’s survival. In the model 03a we had developed thick wool felt around the midrange and tweeter to attenuate diffraction. It worked well, was affordable; but looked less than elegant with the grilles removed. The curved baffle of the CS3 solved the problem elegantly but cost more. In 1982 we were a garage-shop operation. Our sell prices were cost-plus over an unrealistically low dirt-floor low overhead production cost. We needed to break out of me-too boxes to attract more sophisticated customers. My solution was to sculpt these 3-D baffles with ordinary shop tools, some ingenuity and lots of grunt. (We took an 8mm home movie of the process, which may emerge someday.) It goes like this.

Laminate MDF, route the driver mounts with templates, saw 3 x 45° facets with a progressive fixture on a tablesaw. Finish the conical roll-overs with a hand plane, rasp and sandpaper, then apply a wood-flour x drying oil slurry to fill the pores. I sculpted every baffle with one assistant.

One reason the CS3 put us on the map was timing. There was a deep recession in 1981-2 which killed many companies, and most of the survivors came to 1983 CES with re-warmed makeover products. We showed up with the CS3 that looked pretty high-tech / high-investment. It really got noticed.

From behind the curtain of time: Jim wasn’t convinced that "the market" would pay the price for that sculpted baffle. He co-developed an 03b using the same CS3 drivers, but with the 03a felt block diffraction-control baffle. Its introductory price would be $1150/pair @ 15% above the $990 03a. CES pre-show setup day response to the CS3 was so enthusiastic that the 03b never saw daylight. Jim, Kathy and I struggled till the wee hours to settle on the target price of $1850/pair, which J&K rolled back to $1750 at market production. We had broken out.

I consider the CS3/3.5 as the most lucid embodiment of Jim’s vision. This is the model I most want to recreate applying the technologies he continued to invent and refine through the rest of his career.

A lot depends on the particulars and personality of the company. I think Vandersteen and Wilson have survived with a son taking the reins. Some companies survive via economic viability, but even there look at B&W among others who struggle to maintain a viable identity. I am told that Thiel conducted a futile years-long, worldwide search for someone to carry on Jim's work. Niche companies don't offer the financial security or up-side potential that attracts first-rate talent within a winner-take-all capitalist model. I appreciate ctsooner's remark that it's about more than profits. Performance Audio is about the love of music. Making ends meet is what has to happen to support and enable the musical progress and development.

@unsound - the many moving parts are gradually coming into better focus. Neither of those 3.6 drivers is in production. The replacement drivers that will serve the 3.6, 3.5, 3 (plus earlier similar) models will be based on the 3.6 drivers, but can allow changes as we re-tool. I am exploring the crossover changes needed to accommodate higher driver and net system impedances. Jim never convinced me that he was correct in his low impedance jag. In fact, it was a significant disagreement between us in the day.

Regarding 'your' 3.5s and to the extent possible for all Renaissance re-issues, I am aiming for a 4 ohm minimum. The CS2 and previous models hung around 6 ohm nominal and 4 ohm minimum and could be driven very happily with a broad range of amps. I'm working back to that baseline.

 

 

Real - I for one am interested in your comparison of your Krell vs the BHK.

snbeall - Rob at Coherent Source Service might have some definitive answers for you. In general, a big voltage swing in audio is 10 volts.

Interesting thing about hearing is that our brain compensates somehow. My HF rolls off starting at 4K, but I can reliably hear the difference in filter types at 20kHz. I remember a study in the 80s or 90s demonstrating how we differentiate signals on carrier tones even when we can't hear them solo. At that time I could differentiate a 30kHz signal, which we all know is impossible.

I'll visit that Science Review site again. Thanks

@solobone22 - I'd be glad to listen to your test tune; I have a pair of 3.6s in my studio as permanent references. Note that Rob has rebuild kits for that tweeter (CS2.2, 3.6, 5). If it is fried, I suggest sending the whole unit to Rob, because the ferro-fluid can get cooked and thick and need replacement. Extremely low likelihood of XO damage.

solobone - I do not have that Mahler.

You guys are on to something. I got a pair of 3.6s about 1.5 years ago and discovered the phenomenon you all are addressing. It barely, if at all, exists on the CS2.2 or 3.5, of great familiarity to me, and subsequently not very present on the CS1.5, 1.6, PowerPoint or 02. I have spent weeks, spread over months, learning about "tinsel", which I called "sizzle". My observations are anecdotal, but quite thoroughly studied and addressed. This sizzle has led me down a rabbit hole into a warren. I have teamed up with Douglas Pauley who has newly patented a technology to manage turbulent fluid flow - in this case air coupling to the room. Big story there, more later.
The sizzle problem revolves around the comparatively large flat area above the 3.6 tweeter, where the 3.5, for example, has none. With a manual or electronic stethoscope, I can hear the problem distinctly as sonic eddies skittling around that surface. One contributor is the mid-tweeter both driving the same frequencies from different physical positions and geometries. I can stimulate the sizzle most readily with female vocal. Yesterday I hung out all day with the Rhino collection of The Trio - Parton, Harris and Rondstadt. The 3.6s are at the north end of the room with the PowerPoints in the southeast corner and my 02 under development on a corner baffle in the same southeast corner. I switch speakers with knife switches to audition same cut, same equipment, same room at same time from the same listening position. The 3.6s are the worst offender by far.


Cascadesphil - my working hypothesis is that dry air and moist air couple and resolve the various forces differently - not a theory, but a hunch developed over the past year of experimentation. 

Grille cloth helps a little, but not much. My best solution has been pruned from bunches of ideas and materials, landing on UltraFine UltraSuede on F11 wool felt on the entire baffle. I haven't developed a meaningful measurement scheme, and such may be beyond my resources. I know through study that we're in esoteric territory. Another factor in play is the turbulent waveform launch from the drivers. Various technologies applied to driver bezels and faceplates aid in transforming that very turbulent launch flow into more laminar flow. Substantive improvements there.

There's much more to share, and I'll have some news to report very soon.

As I mentioned, I don't have 3.7s. If I were testing them, I would find some music and/or test signal that reliably produce the problem. I would use a stethoscope to reliably hear it. I would then mount felt and test, then add UltraSuede and test. Etc. The process is slow and deliberate. There is room for other input such as internal wire rattling, etc. I saw a video that showed the driver wires fed through silicone tubing. Perhaps that's a culprit. It is interesting that more than one person has heard something similar. I don't know the answer, but I do register your experience. 

Prof - I want to thank you personally for cheering the 02s awhile back. Your enthusiasm caused me to get a few pairs which are now my primary workhorses for comparing solutions and making sense of upgrade package choices.

The stock 02 is surprisingly good. Plus, it is readily upgradeable via braced cabinets, XO components, etc. and the application of the laminar-launch baffles and work in process of the new port fluid-flow technologies. I recommend all of you find some. We'll have both DIY and home-based upgrade packages sometime this year. I have some as Christmas presents with stock drivers and crossovers, with modified baffles and grilles. What a treat to give, And BTW, they shine compared against some current market darlings. 

Try it. Send a PM for more detail.
TT

Hello Scott,

Good to meet you. In these 262 pages there has been barely a whiff of mention of the CS2. I'll attach a tribute I wrote to the CS2 several years ago and add some here.

Generally first generation Thiel models survive a few years before they get replaced by what we learned first out. The CS2.2 (1991) came seven years (longest run)  after the 2 (1984) with over 7500 pair sold - most in our history. Its clear mission was as trickle-down from the model 3 plus benign tradeoffs: Less bass extension, less output capacity, smaller woofer allowing an octave higher transition to smaller midrange for easier transition to the tweeter. It worked.

I'll add that the cabinet material :1-1/8" industrial particleboard of 100% spruce for almost double the stiffness of the later 1" MDF made for one of the best cabinets in our long history. 

To your question, the XO transition serial number was 4901 about 2 years in. Rob Gillum of Coherent Source Service can tell us the particulars, but I have the later schematic. I can supply some back-story. Larry Archibald, then publisher of Stereophile loved the CS2s, but niggled them more than once in print. I found out more than a year later that he listened exclusively without grilles, even though he was told and other reviewers enumerated how integral the grille was to their performance. We wanted Larry to update the record with his better assessment, which he wouldn't do (egg on his face). So Jim looked for an improvement and found an extremely subtle change which gave Larry a scapegoat. Short story is that the grille's absence accounted for the lion's share of Larry's complaint. Also, you may not have the 1" butyl tape anchoring the grille board to the baffle, which brings further significant improvement.

I agree that the CS2 is worthy of upgrade and may have been hot-rodded by some on this forum. But things get a little sticky. That tweeter and midrange are no longer available. The woofer is early but true Jim Thiel with many enhancements. It will stay. Rob has a midrange drop-in if a re-engineered unit proves unfeasible. Understand that newly developed drivers are to fit multiple products in order to justify their development cost. The CS5 needs a lower tweeter which is now an unviable 2" MB Quart dome, and the CS2 and 2.2 need a small midrange. A  3" Thiel driver might fill both the CS2 and CS5 needs. It would use the double-cone geometry and Jim's lifetime motor improvements. This is not a front-burner project, but of great personal interest to me.

Bottom line is that mid and tweeter changes require crossover changes. So you don't want to dive too deeply tweaking around obsolete drivers. All that said, there is some low-hanging fruit for you. Replacing the series resistors with Mills MRA12s makes for an inexpensive and lovely improvement. There are 1 tweeter and  2 midrange feed caps to replace with Clarity CSAs to significantly clean up the sound. Of further note, as many on this forum know, I've been developing new internal wire. It is lab proven and now being developed for manufacturing. It incorporates new art and I am as thrilled as can be about its upgrade performance, including affordability.

Within the foreseeable future your speakers will be formally addressed. For now, I probably have those caps for you to experiment with, and the resistors are readil available. Send me a PM if interested in wading in.

tmsrdg - I don't have a track. My MO is to play more music rather than concentrating on a single cut. So, I skip through the disc to find passages that do whatever I need to do. I will say that disc one is more obnoxious, disc 2 is the best, and the disc 3 out-takes are variable.If I had to choose, I would choose disc 1 as most likely to misbehave. I hope that gives you somewhere to begin. 

Prof - I would love your feedback regarding their sound, when the time comes. I'll say that the more that I improve the technical performance and address the shortcomings caused by our naivete in 1976, the less they sound like Thiel 02s, and the more they sound like more recent Thiels. And it's not simply that better is better.

Tweak - your Starsound wire comment is fascinating. As I seek to reduce jacketing contribution, you are using it as an electromagnetic design element. Are you guys associated with MIT?

JAFant - jazz is great all around for its layers of nuance. And there's a lot of well-made jazz out there. I landed on my wide rather than deep approach to sources partly as a contrast to the usual way. Thiel, and most others I knew at the time, used favorite tracks, known to be well made, thereby minimizing the variable of aural input "noise". I call that deep as in drilling farther and further into the subtleties of that track. But, what if those pristine tracks didn't stimulate the "sizzle / tinsel ", etc. Whatever the cause, a problem could be dismissed as a "bad recording". But what if (as I now suspect) some of those "bad recordings" might just be exacerbating shortcomings in the speaker. This territory is where most of my detective work is happening.

Tweak - can you speak to why you chose iron (magnetic) rather than stone (more innert)?

bonedog - Rob at Coherent Source Service has those woofers and/or rebuild kits. That's the way to go, the hardware lasts forever. That driver is spectacular, an early edition of proprietary and groundbreaking technologies.

thoft - Nelson designed the original GFA555, but not necessarily the other Adcoms. I think he designed all the Forte gear, but I’m not sure. He used the Thiel CS3.6 as a design load, so he would have the definitive opinion for Thiel with the models he designed.

I can contribute a bit of Thiel historical perspective. Among all the good, great and worthy amps out there, Thiel gravitated toward a few brands, who also gravitated toward Thiel speakers for mutual product development. This thought is up to 1995 when I lost touch. Those amps of choice included Krell, Mark Levinson, Bryston and Conrad Johnson (and early Classe & Threshold). Part of what manufacturers need is political affinity: sharing dealers, design philosophy, potential mutual customers, and so forth. But they also need performance-compatible products that make each other sing. There are undoubtedly other good matches out there, I'm just sharing where Thiel as a company, that is Jim Thiel as a designer, felt most at home.

Thoft - I've been messing with the 3.6s for the past few months. I consider their stock components highly optimized and am therefore investigating other upgrades in priority over component upgrades. That said, there are ongoing DIY upgrades happening behind the curtain on this forum - perhaps someone might comment.
I can recommend the fruits of our research, which lands on replacing series feed caps with ClarityCap CSAs in the highest voltage you can fit or afford. Swap resistors to Mills MRA-12s, especially in feed stations.

As background, I have bragged about those yellow caps as state of the art, and they were in their day - tin foil on styrene film, they measure and sound quite good. However CC's CSA invention replaces the normal zinc spluttered end caps with a copper-containing matrix, and updates the geometry to wider and shorter, for a significant performance upgrade. BTW, I've compared the CSAs and CMRs to many of the sexy caps out there, and I believe the CCs are as good as it gets in terms of truth and accuracy, especially at their affordable prices.

Another nearly free upgrade you can DIY is to re-mount the crossover panels on rubber standoffs to reduce vibration in the crossovers.

Tmsrdg - I can add a general perspective comment. The level and extent of exploration and custom development that went into passive components at Thiel was considerable. Many folks may consider Thiel's choices as strictly budget driven, but scores of hours were spent on each product to optimize and match the components both for sound and for cost balance. The biggest exception might be the resistors. Swapping in Mills MRA12s costs very little and has produced noticeable improvement in the several builds we've done recently. I have no direct experience with the 3.7, I'm merely extrapolating from general experience. 

Prof - I’ve only heard the 3.7 and 2.7 once, when auditioning the final prototype 2.7 at the Thiel factory in 2012. We all heard what you are hearing.

There’s probably more to it than the baffle. A few years and $six figures were spent optimizing the 2.7 within its budget parameters. The aluminum baffle is a contributing element, but any upgrade would have to be from outside, since the interior has multiple shelf braces in the way. A person might route a pocket into the MDF baffle front to seat a custom aluminum plate. Serious undertaking that I doubt Rob would take on - but ask him. You would get significant improvement using counter-top laminate (Formica, etc.) rather than aluminum.
An effective and feasible upgrade addresses the 2.7 midrange xo feed which goes through a 400uF electrolytic cap as well as a series 20 gauge feed coil, without any shunt to ground. Jim never used electrolytics in series feed stations (after the 02 in 1976). That "caught in the box" effect is something that big E caps do. I have developed some substitutes from Clarity Cap 100uF x 160 volt CSAs. I doubt you have room in the enclosure for them plus they’re fairly expensive. Note that Jim’s solution for the 3.7 is a cap bridge with multiple 75uF PPs. The feed coil in that station in the 3.7 is 18 gauge for about double the current / resistance performance.
If I were in your shoes I’d consider the following:
Baffle treatment: remove the drivers and the threaded inserts (if any).Mount 1/2" (or larger) birch dowels into holes drilled into the edge of the driver openings, at least an inch and preferably farther behind the front surface. Wood screws into that side grain of the dowels will couple the drivers more tightly to a greater cross section of the baffle. Use viscous gasket goop behind the drivers (Permatex type 2 non hardening) to damp the natural interface resonance. That mounting on a formica face gets you pretty far up the performance ladder.
Crossover: replace that 400uF E-cap with 4 @ 100uF in parallel. Consider replacing the bypass caps with ClarityCap CSAs. While you’re in there I’d swap in some Mills MRA-12 resistors in that series midrange feed. Same for the series feed in the tweeter.
That’s some low hanging fruit and something that a good bench tech could handle if it’s more than you want to tackle. Rob may have suitable parts or advice, or you may contact me for specs and sources.
The 2.7 is a very nice speaker and in some ways easier to take on a broader range of material and amplification than the 3.7. But immediacy and detail are relatively compromised.

jon - you're on it. When developing the CS5 cabinet I explored custom ceramic tiles for the interior, attached with a researched mastic adhesive - it worked extremely well. There were two big problems. 1: it was too heavy to ship and handle. Dealer home delivery was the deal breaker. 2: the tiles were not always flat and the ratio and durometer of the adhesive layer would change the tuning of the enclosure depending on adhesive thickness variability, thereby changing the final tweak voicing of the system.

For your in-place situation, #1 may not matter. #2 is a small issue (and no, I don't remember adhesives options or winner 30+ years on.) It's worth exploring. Also, you will change the acoustic volume of the enclosure, but it won't matter a lot. I suggest finding the most active surfaces with your fingers or stethoscope and treating those. High likelihood includes the top and halfway up the sides. Please let us know what you do and how it works.

@goldbehen - I’ll go so you don’t get left in the dust. It can pile up quickly here.

The 3.5s, like all Thiel speakers are designed to be wide-dispersion transducers. So their off-axis environment is more critical than many other designs. They should be well away from boundaries, particulars depending on your room size, proportions, materials, etc. If you don’t have the setup manual, it may be online, or specific questions can be addressed here. In general try for at least 2’, preferably 3-4’ from tweeter plate to wall behind and at least 3’, preferably more to side wall with those two dimensions being different from each other.

I am only guessing about your ’wall cavities’, but any hard edges near the speaker will add diffraction distortion. A niche behind the speaker may provide an opportunity for absorption or diffraction treatment to help reduce diffraction.

If you mate with a subwoofer, try using the 40Hz EQ setting as your crosspoint.

Good luck and keep up posted.

TT

hifi28 - good speaker, more on that later.

Tweeters are Dynaudio D28 soft domes. Great at the time, nothing special now. The domes can be sucked out through a paper towel core. Creases will remain, but sound is not much affected.

Spikes can be any 1/4" dowel, metal or wood (with care). Or 3 pennies to provide a flat plane. Pointed spikes best on carpet.

Grille boards are part of the system and must be used - fabric is part of the design response. Later version had rubber goo-tape for firmer connection to baffle.

I'll talk about the CS2 later this weekend. In my opinion, you could build a first-rate system around your gear with upgraded CS2s.

 

CT - a few general thoughts here. I am aware that Richard uses the term ’pistonic drivers’ and what he means my it, and agree that it is highly desirable; but there are many designers who don’t want it. There has been considerable convergence of thought around accuracy of reproduction since the 1970s when Richard and Jim were making breakthroughs. I say breakthroughs because at that time it was not widely accepted that ’truth in reproduction’ was a desirable thing. In fact, most designs were developed to deliver their particular euphonic flavor. Within that context, the Thiel / Vandersteen "everything matters, and accuracy is the goal" perspective was unique then, but quite widely accepted now. Note that Dunlavy and a few smaller designers also honored full coherence. The marketplaces of ideas and commerce have not generally supported the extra difficulties of coherence.

In the context of ’getting everything right’, drivers must move pistonically. And as time goes on, more and more do so. I don’t know whether RV has any actual corner on that claim, beyond coiling the term and using it in his promotion. But he does share his design values with John Dunlavy and Jim Thiel, requiring flexural rigidity. I’ll take a little memory trip here. Thiel’s coherence awakening came after the 01 and 02 (1976) which had normal third and second-order crossovers (all polarity-correct.) The 03 development began in that normal way, but veered to first order in an organic procession (which I’ve mentioned here before.) That development of a phase coherent system required the development of more pistonic drivers. Note that many (normal) designs use the flexural cone delay of the circumference lagging the apex as a way to mitigate the reverse-polarity negative going onset transient of the upper driver from the typical second-order, inverted polarity crossover. In other words, a floppy driver causes less of a particular problem than would a stiff driver in that common second-order/ inverted polarity design. But that advantage evaporates with a coherent first order crossover, while keeping the significant time, phase and harmonic distortions of that floppy driver.

So, back to 1978, the final 03 is coherent, but the drivers are ordinary. Next product in development is the 04, a 6.5" coherent two-way. Jim developed a double-cone woofer for that product, which was patentable (and eventually was Thiel patented.) The front cone is a curved flair and the back cone is straight, both driven by the same voice coil and to the same surround attachment. The double cone triangulates the weak circumference, creates double propagation paths (introducing self-damping), uses the air captured between the cones as an averaging medium - all producing a very stiff pistonic system of light weight and low cost. Alas, before the finalized 04 was introduced, one of the cones was discontinued, and no workable mates could be found until we grew enough to commission our own cones.

Please pardon my spotty memory, but as I recall, the first product to incorporate that double cone geometry was the woofer of the CS2.2 introduced in 1990. It took that preceding decade to develop the sources, solutions, patent and manufacturing infrastructure to make the concept a reality. That geometry is used in the CS3.6 midrange and probably other Thiel drivers. I left Thiel in the mid 1990s and don’t have first-hand information of the further trajectory of that double-cone solution.

RV’s solution using carbon fiber over a balsa core is very effective, along with very expensive.

As far as Jim developing his pistonic drivers, I propose that he made steady progress toward that goal throughout his career. In the early 90s, we conducted in-house cone development that significantly improved specific rigidity via material and profile and taper geometry. I further propose that Jim's statement pistonic driver, was the CS3.7 / 2.7 midrange with its radial corrugation diaphragm, which represents a conceptual and technical breakthrough. The 3" diameter voice coil bisects the radiating area such that there is equal mass distribution on either side of the motive force. In other words, the driving force is balanced rather than propagating from a voice coil at the apex to a passive rim at the surround. In cross-section, the (half) diagram is a T with the wavy diaphragm on the top and the vertical stem being the voice-coil former - driving the diaphragm from its centerline. The corrugations keep the diaphragm from bending for a near perfect piston. I would love to see comparative Klippel pix of the Thiel driver vs the Vandersteen driver. I bet they are both world-class and that the Thiel driver costs a fraction of the Steen. I hope that Jim’s driver might live on. I consider it his crowning achievement.

The ESL-63 uses (if I recall correctly) a cascading time delay crossover over concentric rings of the diaphragm to create a whole diaphragm motion with all points equidistant from the listener's ear. What brilliance!
"Walsh" - type drivers use bending in their method of creating the cylindrical column of moving air pressure waves. So bending is part of their basic system mechanics.

Discrete drivers attempt a uniform air propagation wave-front  via multiple driving sources, which must remain flat to engage the air mass properly.
Unsound - do you know if the Walsh-type driver actually produces intact step response at the listener's position?

I know we’ve explored some of this territory before. But I hope it’s worth repeating, especially for those who may not have read all of our 220 pages.

Ever wonder what Amberwood is anyhow? And its brother Morado? As time went by, Thiel wanted a standard-priced offering that was unique and upscale, and fit a broad range of living environments. From the beginning we offered what I considered the premium woods of the world: Black Walnut, White Oak, Teak and Brazilian Rosewood (for very little upcharge) because we could, because we made our own veneer faces and laminated in-house. So we could buy flitches of raw veneer and use it as needed. That may seem ordinary, but it’s really quite far from it. Most speaker manufacturers don’t even make their own cabinets. And the cabinet maker doesn’t lay up their own veneers, but rather buys veneered panels ready to machine. By 1990 we were making 5 models in 5 standard finishes plus practically unlimited custom options. Can you say complicated?

A growth strategy was to reduce variety by creating a target finish that would allow a large percentage of sales from stock rather than made to order. Our demand was fairly evenly spread among the existing finishes, so I went shopping for something new. Landing on a domestic species would have been nice, since we had two world-class veneer mills within 80 miles of us. But, that didn’t materialize.

What did materialize was a walk-about to South America with Jungle-Jim Martin a second-generation woodman who ran Marwood, a leading specialty veneer importer down the road in Louisville, and president of "The Hardwood Forestry Fund", a leading industry conservation group. We planned our first joint trip in 1989 specifically to identify a good supply channel for a magnificent wood from responsible forestry practice, that we could afford. There’s no way to ascertain responsibility/sustainability without first-hand inspection of the suppliers on their own turf.

Over two weeks, we visited 14 mills in 11 cities (locations) throughout Brazil and Bolivia. We knew some candidate species from my 15 years of making custom furniture, musical instruments and loudspeakers. But the scouting process was real and open-ended and one that paid dividends far into the future.

It’s pretty well known that the world has a resource depletion problem. By 1990 the outrage had taken two tracks. The Europeans claimed to boycott "bad actors" where the Orientals tried to verify "good actors". The Americans tended to pretend that everything was fine. Most of the real practices bore little resemblance to claims or published information, even "officially" documented and audited claims. Round wood at the source is little different from other extractive resources like oil, coal or diamonds - it’s quite dirty, getting progressively cleaned up on its way to the consumer.

But I could go to the source with Jungle Jim and shine a light on those layers of obfuscation. We took a mutual friend, a well-traveled, well spoken woman who could ask pointed questions in non-confrontational ways that were unavailable to us as guys in a very machist milieu.

Many of these mills were regular suppliers to Marwood with reputations for best practices. But under scrutiny, all the Brazilian sources fell apart regarding sustainable and ethical practices. Corruption reigns. The wood of choice firmed up as Pau Ferro, most often marketed as Santos Rosewood. It’s neither a true Rosewood nor from Santos, a port in southern Brazil a few thousands of miles from where it grows in Bolivia. That’s its point of export to the western markets.

Out travels led us to Bolivia where it grows. Santa Cruz is in the uplands between the Amazon Basin and the Andes. The area produces very good timber, which was comparatively quite responsibly harvested, primarily by Japanese mills exporting a range of raw veneer and lumber with semi and completely finished pieces and parts back to Japan. The picture grew much darker eastward into the backlands toward Brazil. Poachers, primarily German nationals, routinely carried out stealth logging raids, complete with pneumatic chainsaws, a convoy with a helicopter and machine guns. As a naive gringo, I would not have believed what I saw with my own eyes.

With Jim Martin’s Forestry Fund clout we were able to arrange a project of a life-time, working with the University of Santa Cruz and the Bolivian Forestry Department to create a long term sustainable yield program with the Chiquitano Native Peoples. The kingpin is that their tribal lands were secure. Of course they had titular property rights - that the poachers could ignore. But they could’t ignore large-expanse swamps with serious snakes, arachnids and reptiles, along with unimaginably agile canoeists armed with curare darts. A seriously secure site into the foreseeable future.

We need to jump over lots of wonderful details to say that we established a well managed, continuous-yield program that netted the Chiquitano natives a lion’s share of income, along with the best-of-class SUTO veneer mill for a long-term contract supplying Marwood, with Thiel consuming enough veneer to stabilize the whole program, which continued until Thiel was sold at the end of 2012.

The wood of interest goes by many names. Pau Ferro is the catch-all meaning Iron Wood, which applies to many tropical woods of similar type. Santos Rosewood is a lie, even though all the Danish Rosewood furniture since the 1960s has been made of this wood. It is in the same family as the Dalbergia genus rosewoods, but I felt it disingenuous to call it such. Complicating matters, there are two species, lowland and upland, that are all marketed together. So we coined two names. For the lowland species, I applied the local name of Morado which means ’purple’ in the local tongue. The upland species is lighter in color as well as less color-fast and bleaches toward blond. We named it Amberwood.

Because we were dealing directly with a responsible source and exporting via ship all the way to the Port of Louisville, 80 miles from Lexington, we kept the cost within reach and competitive with our local species. We went on to buy over a million square feet through that ongoing program. The offering was a hands-down success and our peers couldn’t believe that we could offer it at standard pricing.

As with many things in life, there’s more than meets the eye; it’s more than a pretty wood. I’ve only told the high points here. There’s a whole lot to love about Amberwood / Morado. I’m glad when people share that love.

 

 

 

 

 

 

JA - and it is real music from really talented musicians.

Yes, of course. That circuitry is already extant in the eq. There is only 6dB of boost at 40Hz vs 12dB @ 20Hz. Tomorrow I'll run today's trials at 40Hz vs straight wire.

These sketches I’ve written in this forum over these past years serve as remembrances and motivations to resurrect and stitch these events together in my memory. I believe a memoir would be valid, not just for fans of Thiel loudspeakers, but as a marker in time, of a time when some folks in their twenties in Kentucky with only their vision, will and guts, could actually pull it off, becoming a player (albeit small) on the world stage for nearly 40 years. I’ve given you guys some glimpses and contexts, and as can so often be said: there is always more.

When I found this forum in 2018, it gave me a welcome platform to speak to some ideas and issues meaningful to me. I have appreciated and enjoyed it very much. It also allowed me to formulate and develop the idea of Thiel Renaissance, which still lives. I am still resurrecting stories and developing product improvement ideas . . . but, we can’t always get what we want. The loss of my workspace has been debilitating and is still consuming much of my time and energy. So progress on any and all fronts is very slow.

On the bright side, the sale of my tonewood business has allowed all my current projects to be music-centric - and that feels like coming home.