I'll throw some thoughts into the mix.
Critical listening in an unknown space with unfamiliar gear and recordings is a challenge. In this case, the room had been designed to be modifiable for feedback from FuzzMeasure analysis, with which I am quite familiar and fairly adept. The room features a structured masonry / brick front wall and solid, infill masonry side walls. Such a rigid room makes for exceptionally clean sound, but carries downsides of pesky modal behavior. We borrowed 2' behind the listener from an adjoining room for a tunable chamber. Room side, right behind the listeners, is a unique porous wood-sliver panel, floor to ceiling, wall to wall. The acoustical panel drop ceiling at 10' has a 2' x room-sized chamber above to generalize the floor-to-ceiling modes. That sealed chamber still needs two short dividing walls to isolate it from a very large attic space. Chasing slap echoes, tuning modes and identifying further work to be done on the 4 deep-set windows consumed much of our time. We used music along with test tones and sweeps for this work - any music with broad-range content would work - and did. By Sunday morning we could compare and contrast the playback system elements under consideration.
Reference cables included Morrow and Straightwire as well-known to me, and some serious foreign contenders that Max knew and loved. We settled on the Morrow as baseline to demonstrate my TRX interconnects and internal hookup wire. TRX is Thiel Renaissance X (24th iteration) - of major conparisons, not all TR. We benchmarked via Benchmark, Iconoclast, Cardas, Audience, Straightwire, Kimber, Morrow, and many home-brews to try out ideas as they surfaced. Suffice to say this wire dive was way deeper than the original late 70s exploration, the 1988 CS5 re-examination and the 2005 survey for the CS3.7. Incremental progress was made via input from the above-mentioned collaborators as well as advanced interaction with MIT operatives.
I am aware of wire skepticism. My approach is not fundamentally skeptical, but is strictly evidence-based as well as requiring theoretical foundations. This family of analog signal cables embodies those requirements. Most of all, it must perform demonstratively well on all fronts. I have employed a hefty handful of listeners along this trail. This trip expanded to include duramax747's assessment. Feedback/ input has been extremely consistent and positive. Disappointments and dead ends have mostly been attributable to available materials and compromised methods of the prototyper's constraints.
If I were to propose adjectives, they run toward clarity, detail, and depth of structure. All support Thiel's core performance attribute of 'vivid solidity'. The measurements support the subjective sonic experience. The outcome reflects the lessons learned along this deep-dive journey. We are especially encouraged because among prototyping limitations is working with available materials and methods. I use magnet wire with polyamidimide insulation - far from audiophile standards. My positioning filler is fibrated polypropylene, which is first-rate, but my hand twisting loom is far from the precision of real planetary machinery. A technical description of the cable will have to wait for decisions by the working group as to IP concerns.
Back to Max's room near Charlotte - we had various iterations of the SCS4 from stock Thiel to fairly hot-rodded - TRX internal wire to outboard XO with serpentine layout honoring waveguide principles with elements arranged for optimized field interaction, upgraded cabinet edge treatment, custom proprietary multi-segment caps from Reliable, and fluid dynamic wavelaunch technologies from Douglas Pauley. This wavelaunch tech is the most surprising and exciting aspect of this redevelopment work. I would have never thought that Thiel's already excellent anti diffraction wavelaunch could be qualitatively improved. The improvement allows the soundfield to hang in space. Max's first response after demonstration regarded 'projection'. Among the multiple causes of that 3-D spatial projection, Doug's wavelaunch tech leads the pack.
I believe that we have developed synergistic, meaningful, cost-effective methods to take my brother's designs to a higher performance plateau without modifying any of his work and achievements. I am encouraged.
Back to music. Max had a variety of big, bold, well-made recordings. I used two for orientation: Patty Larkin's 'A-Go-Go' which is a composite of live, on-stage recordings / one woman with her guitar with minimal artifacts. Straight-forward, well-done music making by a master whom I know, who's guitar and maker I know well, and that I have heard live in my small village venue. I believe I know her musical intentions. The other was Dana Cunningham's premiere 'Dancing at the Gate' which I produced from a simple music-school stereo recording to DAT and mastered with no compression, EQ or other artifacts. Contemplative piano on the half shell. My post-Thiel life includes lots of piano involvement including an innovative bridge and soundboard bracing system. These artists are interesting, involving and careful with their presentation. Subtle playback system mods track better when we care about the music. Last weekend was a wonderful musical experience for me.
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tmsrdg - it’s weird stuff, and addresses something where Thiel already excels. The terrain is the integrity (or not) of how the driver energy translates into the limp air-mass for you to hear detail. Thiel’s bezels, waveguides and curved baffles with pebbled finishes all address this issue. But further research demonstrates the audible effects of wavelaunch turbulence. In short, the moving driver diaphragm moves air up to its modulus of deformation - it misbehaves as it tries to establish a coherent wavefront in the air. By modifying the surface to better manage the sheer forces and turbulence in the boundary layer between the non-moving baffle surface and the moving propagation wave, we define wave-fronts with considerably more integrity.
Douglas has patented two interlocking technologies: one addressing the propagation surfaces and the other managing the boundary layer behavior in the port itself. I was exposed to this nascent tech in 2018 and have been co-developing it for these past 5 years. A surprise is hearing a type of sonic improvement where you wouldn’t expect needing any.
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tmsrdg - patience is the key.
The 3.7 is late model classic Thiel. Its ’needs’ are far closer to ’wants’ than earlier models which have far more real problems, upgrade potential and far more head-count in the field.
But to address your question, there will be a multi-pronged development and delivery. Each model will have its own upgrade protocol. Your 3.7 drivers are ’settled’. Your crossover will have some user installable upgrades. Specifically some of your Yellow Styrene 1uF bypasses will have replacements by way of custom Reliable multi-sectioned caps, in either aluminized or all-copper, as well as various non-inductive resistors. At some later date those upgraded parts can be re-used in a new serpentine XO layout, either inboard or outboard.
This first-offering upgrade will also include a set of wavelaunch films which can be applied by an adept user / or via some other arrangement - as yet unknown.
Similarly a new internal wiring harness will be available to be routed through the existing soft tubing, possibly with additional hold-downs. The new cable has less structure and depends more on mechanical support from the cabinet.
These examples are illustrative of future vision. At this time we are starting with training wheels with the SCS4, either extant, or new higher-grade specimens. Lessons learned there will be applied to next-step offerings, addressing older models with larger problems, such as replacement drivers and generally more room to grow. CS1 through 5 models will get early attention, starting with the CS3 / 3.5.
This information is a peek behind the curtain. There is ongoing work being done and many moving parts.
Cheers, Tom
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I apologize in advance for many of you who have heard this before . . . I am a big fan of the sealed bass in the CS3 and 5 series. In fact, Thiel was philosophically committed to sealed bass in its upper models, while allowing reflex bass in its lesser models with the cost savings reflected in the lower sell prices. The main advantage I see in sealed bass (whether equalized or not) is the phase / time coherence all the way down to the low limit, and then 12dB/octave to subsonics. That is radically different from reflex bass which attenuates the woofer at 24dB at its bottom and the port at 24dB at its bottom and top rolloffs. That puts the foundational deep bass a full wavelength behind the upper frequencies. That's 20+ feet, depending on actual tuned frequency. Philosophically that runs contrary to Thiel's committment to wavefront integrity.
When that direction was coming to be in the 3.6, the mood was more relating to what others' products (even with 6-figure prices) were getting away with. Some of us are more sensitive to the philosophical integrity, and others notice the sonic discontinuity of reflex bass. Note that Thiel reflex bass is executed as well as I've heard it. Look at the clean graphs and the tight tuning. But . . . it's still not the real thing.
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caseywkc - you have ruled out the woofer. Have you tended to the inner passive surround? There's an outer and inner surround.
Here goes a strange and wonderful exploration. I've used my pair of 2.2s as workhorses since 1990 and conducted my early Thiel Renaissance explorations on them. The problem you describe has been considered a design limit since their introduction- although your symptoms may be worse than typical.
'Your' problem actually happens on some other Thiel models, but the 2.2 is the worse. The root cause is electrical field interactions between the woofe, the crossover and/or the hookup wire. Taking the XO out of the cabinet and/or moving it to the cabinet bottom, and/or attaching the hookup wire to the cabinet fixes it. The simplest element of the problem is a feed wire vibrating against the cabinet or driver. But your case sounds more dramatic than a simple wire buzz.
Troubleshooting this problem led me to a systemic improvement applicable to all models, which I call 'Serpentine Feed'. We eliminate potential bucking fields caused by feeding and tapping XO circuits on the same side of the XO panel. By feeding from the back and tapping from the front, fields always blend rather than buck. The improvement is not subtle. I go further in my new XO layout to leave considerably more space around components for more propagation field management. A random element is that reversing feed direction or orienting a coil 180° can fix 'it'.
I don't have a specific 'fix prescription' for your problem, but this is the nature of the riddle. Feel free to contact me privately for further coaching.
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Cabinet leak is a good idea. External is unlikely unless there has been cabinet damage. Loose driver screws could cause a leak. Also between the large/woofer enclosure and the 6" midrange tube enclosure. Check that by pressing the midrange and seeing if the woofer / passive radiator move.
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theaudiotweak - Tom, I don't remember ever studying port position. When we were developing our knowledge base, the opinions, even among the academic / gurus was wide and varied and often contradictory. We found that ports placed near boundaries, such as a baffle corner, exhibited more turbulence evidenced by misbehavior in its upper rollout. Best results were with the port placed as close as practical to the woofer, with no insulation between them. The biggest deal turned out to me the port terminations. Roundover entry and exit works well. Take a look at the SCS4 and its graphed performance. Two ports reduce flow to half. The external opening is a tractrix horn and the internal tube gains diameter going toward its inside terminus. I've never seen a quieter port.
Rob says that geometry was Jim's original work.
My work with Doug has further reduced turbulence by addressing surface propagation boundary effects. The improvements are significant.
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As with all Thiel products, the first generation breaks ground and the next generation(s) add refinement. I can speak directly to the CS7 which went into production at the end of my tenure. Its primary problem is its concrete baffle - an error in my assessment. Concrete shrinks and eventually cracks, most notably at the sides of the woofer and/or passive radiator. That can be repaired with epoxy. The 7.2 switched to a mineral/polymer casting without the shrinkage problem.
The biggest performance difference is the next-gen drivers in the 7.2. Those years from 1994 to 2000 showed significant progress in motor and diaphram design. The 7.2 tweeter (if memory serves) has 20dB more dynamic range than the 7 tweeter. (Lessons learned developing the CS6 which came after the CS7.) The other drivers also sported enhanced motor shunts and driver geometries that added significant refinement.
Rob says that most of the CS7s were field upgraded to 7.2 drivers and XO tweaks while retaining the CS7 cabinet as-is. Broken baffles were sometimes factory swapped to CS7.2 baffles.
I have a pair of CS7.1s - 7.2 drivers and XOs in a CS7 / concrete baffle cabinet - with cracks that don't bother me. I directly compared the 7 vs 7.2 at Rob's CSS in 2012 and reported that the 7.2 is cleaner / more pristine and dynamic. The CS7 has an 'easier', more laid-back presentation. I'm told the frequency and phase responses are virtually identical. The upgrade is in the faster, more dynamic, more linear driver response of the CS7.2 drivers.
I would suggest that the CS7 should sell for significantly less than the 7.2 on the used market. FYI: there were around 1000 pair of 7s and 2500 pair of 7.2s sold which fits the general pattern of next-gen sales increase ratio.
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Tom D - theaudiotweaktheaudiotweak
All the factors you mention led us away from ports except for small / inexpensive speakers. A passive radiator obviates most of the problems you cite. For those ported models, my new work introduces both surface flow and film resonators to make the port very much more ideal. The difference is significant. Those technologies are suitable for any / all ported speakers. I hope to have beta-ready trial kits this year.
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The CS5 was designed 'on demand', most notably for the Japanese market which wanted a 'Hear God' loudspeaker from Thiel. As such, the CS5 displaced a potential CS4 which would have been an incremental advance over the CS3.5. The CS5 was also on a forced time-table because the market was brimming with new 'statement' models from many manufacturers. Contrary to street talk, the CS5 was not a 'price no object' product. It respected and solidified Thiel's approach to working within budgets determined by eschewing superfluous costs and concentrating on high-value, cost-effective solutions. Our internal, working retail target was $15K/pair, but by trimming fat, we brought it to market at $9300/pair. As manufacturing director, I advocated unsuccessfully for a higher price with further enhancements - notably more advanced cabinet construction.
By 1988, Jim had taken the plunge into Finite Element Analysis which he applied to driver design to develop many solutions that subsequently became embedded in the industry at large. His first FEA-enhanced design was the 1988 CS1.2 tweeter with a copper voice-coil shorting ring which shunted voice coil eddy currents to meaningfully increase onset transient integrity. That driver paved the way for the more ambitious CS5 UltraTweeter with underhung motor topology and 1/10th the distortions of previously available drivers (at any price.) The UltraTweeter served the CS5, CS5i, CS3.6, and CS2.2. It was dead-ended by our choice of coaxial tweeter-midranges to solve the inherent vertical interference problem of first order x time-aligned drivers. The CS5 upper midrange was an off-the-shelf MB-Quart 51mm dome. Those two top drivers are the same in the original CS5 and the later improved CS5i version.
The CS5i applied newly developed motor changes to the lower midrange, woofer and two subwoofers. Specifically, we had identified pole-piece eddy currents as a previously invisible, but sonically important distortion mechanism. The first-generation solution was to taper the diameter of the pole piece from its required diameter at the voice coil, gradually diminishing toward the motor back plate to better manage the magnetic fields. These improvements were made possible by developing our in-house driver development lab in the early 1990s. We iterated dozens of proof of concept drivers with 1-day turnaround rather than 1 month turnarounds working with our Danish (Vifa / ScanSpeak) supply partners. We made all elements including cones which we spun with our shop-made mechanical/hydraulic spinner. The hand built prototype driver was driven 40 miles to Eminence Speaker who had made our 01 / 03 woofers and had the first Klippel development system in North America. They authenticated / verified our lab measurement results and projected Thiele / Small parameters.
Bottom line is that we upgraded the motors of the Focal lower midrange, and ScanSpeak woofer and subwoofers with tapered pole-pieces and tapered-edge top plates. Those drivers use the same moving system and crossover circuitry as the original CS5 while substantially improving fidelity. Most CS5 owners upgraded to the CS5i. That upgrade kit included the 4 new, drop-in drivers only.
Rob at CSS has no CS5i drivers, but he does offer moving system replacements which are the same for the CS5 and CS5i. The only visual difference between the 5 and 5i is the mass loading of the subwoofers. The original rubber mats proved troublesome via eventual corner lifting of of the mats. The 5i MDF center plugs perform the same loading function without the hassles. If you find a pair of original 5s, the bottom 4 drivers have state-of-the-art 1988 technology. The CS5i subs, woofer and lower-midrange drivers substantially better that performance in the low end.
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devinplombier - guess that was somewhat dense. Let's try again.
If the 2 subwoofers have visible rubber mats on their cones, they have not been upgraded to CS5i status because the CS5i MDF plug replaced the rubber mats for mass loading.
The MDF plug looks like a small hockey puck where the dust cap used to be. Those plug drivers have the new motors, and at the same time the woofers and lower midrange were replaced with the new motor version, even though those 2 drivers look the same as the original CS5.
Rob says the 5 to 5i upgrades were all in 4-driver sets, so there probably aren't any mix and match hybrids around.
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I'm sorry to say that I do not. I've invested considerable time and effort trying to find/locate that information, to no avail. I do have a new lead via access to some of Jim's back-up files. I'll let you know if I can crack that data.
I have and love my 3 working SmartSubs, but have only heard about the Integrator second-hand.
I haven't given up hope, but the original information seems to actually have been thrown away by the first New Thiel crew.
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andy2 - Here's some history. The CS2.4 coax was designed and built in-house and tested with our custom rig. Rob Gillum participated in and periodically supervised the manufacturing process. Rob's rebuild includes replacement of the moving system (if/as required). His replacement moving systems are the actual parts made and tested in Lexington. And, he knows his business. The drivers I've gotten from Rob have all been spot-on in every way.
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Jim - You are correct, the EQ circuit boosts the bass starting at 300Hz to 12dB at 25Hz. Our initial intent was to EQ the woofer and leave the midrange and tweeter unaffected, but the slow XO slopes required grouping the woofer and midrange to keep the frequency response correct - resulting in far less efficacy for the bi-amp idea.
Note that any perceived differences in the upper range caused by the EQ are indeed real. They are artifacts. In that regard the CS3.5 EQ was a performance advance, and is a drop-in swap.
Note that the bi-amp configuration caused more problems than it solved. For one thing the tweeter-only amp is a lot of cost for little return. Also, to maintain proper frequency response, the two amps must provide equal gain into these particular loads, which is far from trivial. Likewise, the cables must be the same as well as same lengths to maintain proper time alignment.
Our rather extensive testing confirmed that a single amp and single cable always outperformed the bi configuration. Going forward, we swam upstream with that single input approach.
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Andy - I have no inside information. Rob is in a difficult time with his failing mother. CSS is viable.
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Hi Tom - Lots of experimentation and solid results. No viable manufacturing capability yet.
The wire / cable journey has been a very deep dive. My solution is unique, effective and manufacturable. I have benefited from Ray Kimber, Mike Morrow, Steve Hill (Straightwire), Cardas and Galen Gerais at Iconoclast / Belden. My bottom line is that stranded wire is inferior to solid wire. Extruded insulations do harm, even the revered PTFE. Dielectric effects and signal propagation integrity are far more important than metallurgy. Connectors matter a lot.
Since my cable contains proprietary elements, I must be careful and incomplete in what I say.
The hookup wire is gauged per driver. Bigger than big enough is too big.
Each polarity leg consists of 2 half-sized conductors to raise the skin-effect saturation point. Cable is star-quad with a core drain to ground static charges, especially on drivers. The core drain provides some shielding (shading) without the tunnel effects of an external shield sheath. Drain and signal pairs are decoupled via counter-rotation and spacing.
Individual wires are enameled at 0.00075" film thickness for qualitatively lower effective dielectric constant than any insulation, including PTFE.
Cable layup uses round spacers to isolate wires with minimal (tangential-only) contact. Therefore most of the isolating is done via air-space.
Having no conventional insulation, the cable has very little body. Its integrity is supplied by fastening to cabinet walls and braces via adhesion to natural cork and cotton string tie-down. This exoskeleton wire becomes part of the cabinet and therefore is connectned to the crossovers and drivers via concentric / axial connectors.
Routing is more carefully away from driver fields, as are crossovers which are now on multiple boards to decrease field interactions between components.
There is a family of analog cables. Signal interconnects as RCA and XLR, speaker cables terminated in either locking bananas or GR Research Electras (Hint: Propagation field integrity matters most) as well as internal wire harness.
Obviously my 2024 introduction date is wrong. But, continual progress is being made.
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The role of audio wire/cable has been routinely underestimated by mainstream engineering. However, in aerospace and now in high-speed digital technology, wire has risen to the status of a system-limit - and therefore importance. There are some design engineers who state that audio cable is a large multiple more complex than digital cable. Audio must support radical changes of voltage and current with back-forces. The problems are real and the solutions difficult.
The speakers you cite are taking their best guesses and engineering solutions within their defined parameters. Those parameters, understandings and blind spots vary widely among designers. Welcome to the murky world of audio engineering.
My recent deep dive builds on Thiel's history. In 1977-8, we faced the daunting task of whether we would tackle the impossible dream of coherence. We found that a coherent source showed glaring problems which vanished when reverting to normal high-order, non-coherent topologies. A near deal-breaker was a persistent gritty, homogenized haze in the coherent iteration that defied our attempts to understand and mitigate. Our aerospace-physicist (non-audio enthusiast) cousin made a visit, heard the problem and suggested we all (everyone) were hearing the effects of inter-strand cross-talk as learned from deep space probe image retrieval. Lesson learned included how our audio neurology processes coherent audio input at qualitatively higher scrutiny than non-coherent input, which it categorizes as artificial and less important.
I suggest that you would hear significant, qualitative differences between your two, or any, cable scenarios if using a coherent source such as Dunlavy, Thiel or Vandersteen, whereas those differences would fade to near meaningless with any non-coherent speaker.
My present work is, of course, with Thiel speakers. I've used the CS2.2, 3.5, and now extensively the SCS4. But the lessons apply to all speakers, and become meaningful for all coherent speakers. I thought that Thiel's 1978 model 03 brought the use of solid, rather than stranded wire, but we later learned that Dahlquist (from aerospace) used 18 gauge solid in the DQ10 darling of the day. Our 18-2 solid twisted pair in teflon spanned Thiel's whole timeline with critical comparative re-evaluation in 1988 for the CS5 and again for the 2007 CS3.7.
Regarding variable gauges for frequencies - the differences are subtle, but again, become meaningful for coherent sources. The math that describes propagation in wire diverges in the lower audio frequencies. Below 1kHz the rules get squishy and below 100Hz the rules diverge. Bass frequencies are supported with greater propagation integrity with conductors with lower surface to core ratios. So larger gauges are 'better'. Happily, skin effect saturation frequency also decreases since woofers are attenuated in the upper audio octaves.
The soup of interactive ingredients is extremely complex. The cable that I have developed makes sonic and measured advances without harm in Thiel's coherent topology.
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Yep - those 48 strands work out to 25awg good to 85kHz saturation / 2 for layup loss. All good except. My quibble is that a tweeter works around 5 watts for negligible current demand. Meanwhile that entire conductive mass must be charged and discharged at every cycle. A single pair of 25awg per leg would allow simple helical layup, carry the required current and produce greater, audible immediacy. You could read that immediacy as a shorter up-ramp of the onset transient with a cleaner initial onset and peak reversal.
You're 'one great voice' is a good visual. My mantra is 'vivid solidity'. You know it when you hear it. The dozens of cables I've tested all sacrificed that vivid solidity enough that I felt compelled to take Thiel's original solution to the next level. Obviously that's a different place than the vast majority of brands have gone. Indeed some Thiel upgraders have gone to various stranded solutions and liked the outcome. I prefer and am perpetuating Thiel's pursuit.
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I'll vouch for the 1.2 as being the first second-generation Thiel speaker. It preceded the CS5 and as such was the working trial for our first copper motor shunts, and aluminum dome tweeter. This was the first product to benefit from our investment in Finite Element Analysis. And it shows.
The CS1.2 is one sweet speaker as is, plus it lends itself very well to XO component upgrades.
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The CS5 and 5i are identical in their requirements. The only difference is the 5i has woofers that Jim improved via incorporating his motor shunts and focused gaps, which do not change power requirements.
The Apogee line, as I recall, had nicely resistive (non-reactive) impedance profiles above 6 ohms. No problems. But their efficiency / sensitivity was extremely low at around 80dB/W/M. So they needed lots of watts to drive them.
Thiel speakers share the nicely resistive, non-reactive impedance profile, but have very low impedance across the board. The CS5 used a unique method of low-frequency extension where the 2 sub-woofers were paralleled to halve the impedance in the very deep bass. The magnitude drops smoothly from about 6 ohms at 10kHz to 4 ohms at 1kHz to 2ohms at 20Hz (and about 1.7ohms at 10Hz. That punishingly low deep bass impedance occurs where there is little musical content. Predicted performance was better than real world performance because many / most amps become unstable/erratic when delivering large current flows demanded by low impedance, even if those flows are not large. Amp designs vary greatly in this area and likewise does the nature of the sonic malaise.
Krell and Pass address the issues very well, as do others that the marketplace has identified over the years. You all have your finger on that pulse far better than I do.
I have personal experience with the early 100 watt Classe DR9 designed by Dave Reich with robust current capability. When bridged it supplies 400 watts at 8 ohms, 800 at 4 ohms and 1100 watts at 2 ohms. I had mine hot-rodded by Bill Thalmann at Music Technology for significantly improved definition and noise performance over stock. Perhaps I’ll take them to Duramax’s place to compare their performance to his later, more sophisticated units.
I wish that Jim had paid more attention to impedance magnitude. The stew could have been stirred to raise the values by a couple of ohms without significant sacrifices. But as it is, extreme care in choosing the amps driving Thiel speakers pays high dividends.
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I don't know much about the Apogee line across the board. There are other high-end brands and models - Wilson Watts come to mind - that are have treacherously abrupt impedance swings with sub-1 ohm bottoms . . . and advertising that claims them easily driven. Thiel speakers present extremely resistive, non-reactive loads. But since their impedance is (too) low across the board, many amps just can't deliver the juice to drive them well.
Duramax's advice is spot on. Listen to demanding material at high volume and assess the enjoyment / naturalness of your response. I find it less than productive to try to analyze and describe the nature of the failure(s) because there are so many interacting factors and such academic understanding isn't the goal. Finding worthy ancillary equipment is your goal.
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duramax - I'll be happy to ruminate on the CS5 baffle. The CS5 followed our 1987 CS3.5 which was a runaway hit, and our most expensive product to date at $2450/pair. Times were good, the market was hot and many manufacturers were presenting $20,000 statement speakers. Jim was extremely uncomfortable presenting anything over $5000/pair. So the CS5 actually represents quite an internal struggle. Contrary to statements that the CS5 was a 'cost no object' design, it actually carried compromises to keep its sell price well below $10K for a design with a natural price around $15K. Let's talk about the baffle as an example.
The CS3.5 had a machined 2" MDF baffle with braces. We also fastened the drivers with 2" screws through the entire baffle thickness into hardened pilot holes to best distribute reactive loads. An equivalent baffle for the CS5 would have been 4" thick and still fall short on impulse integrity, and add significant size to the enclosure. To develop a relatively thin-wall baffle with significantly higher stiffness and hardness, I engaged a local marble shop (sinks and bathtubs) to make samples from shop-built molds. By using 3 marble grits we reduced the polyester binder resin to half of typical and increased the stiffness by nearly double while nearly eliminating ringing. That baffle was (I think) about 20mm (3/4+") thick providing considerable internal enclosure volume.
We kept the overall size of the CS5 to no larger than an average woman. Jim invented a bass alignment that paralleled two subwoofers with a full range woofer such that all three were producing low bass at a declining impedance to draw additional power, but in a range that rarely has much musical content. It works and I hoped to apply the concept to further products, but we changed course to reflex bass due to its far lower cost and problems.
Riffing on the baffle: we designed the cabinet around the shrink-factor of that 'dry' triple grit baffle pour. We also developed a dye process for the marble so we could use a clear gel-coat showing off the marble grain. A next-generation concept (we always looked well ahead) enhanced the triple-grit concept to include granite, basalt and marble for even lower resin content, higher stiffness, greater internal damping and a more stunning look. But from a more conservative viewpoint, Jim and Kathy re-budgeted the CS5 at $9300 retail, so we had to lose the dry triple-grit x clear nicesity. The 'normal' pour gave the baffle more shrinkage and the cabinet dimensions shrank a little for it to work. Somewhere around the first 50 pair of CS5s had black gelcoat polished directly off the mold. But mold maintenance had also been deleted from the budget and all the rest of the 500 pair model run were cast with a primer gelcoat and sprayed in-house with emron (aircraft epoxy). My production records showed that those 'budget' baffles cost considerably more than the original, superior baffles would have. Such things happen when non-manufacturing executives step in.
As was our habit, we accumulated ideas for the CS5.2, which never came to be. The home theatre market was steam-rolling much of the esoteric high-performance marketplace. Jim wanted to go where he could design / develop more products faster, which was not a CS5.2. To a similar point, the sealed bass with its natural 12dB/octave in-phase and time aligned output was jettisoned for reflex bass in future products more or less because everyone else was getting away with it. That's a discussion for a different day.
Another point is that Jim wanted the CS5 baffle to follow the tilted flat plane of our other products. That necessitated electronic bucket-brigade delay on the upper and lower midrange drivers accounting for nearly half the component count in that huge crossover. Those coils and caps are all in the signal-feed path, which creates most of the sonic reticence experienced in the CS5. Now, close your eyes and imagine an arc-plane baffle that eliminates that electronic delay in favor of proper physical driver placement. Can anyone visualize a CS5.2?
As it stands, the cast marble baffle of the CS5 is enormously effective and beautiful. That product is a testament to a time when people of fairly ordinary circumstance could afford a product that still holds its own 35 years on.
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devinplombier - we did explore low level crossovers. Net result is that we knew our niche which was all analogue and purist. Other folks have done versions of what you suggest. We always looked at overall cost effectiveness and separate amps, cables, etc. are not cost effective solutions, in our opinion. Also, the time of the CS5 development was 1988 - early and crude digital performance.
Of additional interest may be that the level of control needed for net resultant 6dB/octave slopes over approximately 7 octaves is far from trivial, even with digital modeling. We committed to minimum phase x time aligned performance with the 1978 model 03 and never looked back. Note that one would need to model, in addition to the driver roll-off slopes, the various reactive circuits to cancel resonances as well as the impedance correction shunts to maintain Thiel's resistive (non-reactive) load profiles. Most folks are very surprised how difficult that is with off-the shelf digital filters.
The approach we were intrigued by is low-level, active analog circuits before the power amps. In fact one of our first, pre model 01, trial products in 1975 was just such a speaker with 3 built to order amps and custom active crossovers in a 10" 3-way in a large bookshelf format. That product was unfeasible for a new company in a farmhouse. The technical aspects were manageable and indeed prototypes were impressive. But we lacked the stuff for market education and penetration. Indeed, powered speakers never became very popular.
To your question: we envisioned a lot. Line sources, spherical globes, di and bi poles. Active equalization was our first market entry and contained enough uniqueness to create more demand than we could meet for the next 30+ years.
Cheers, TT
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lars - a few thoughts. I have rather recent acquisitions of both CS5i and CS2.4, but not much actual experience with either of them. I’ll jump to my conclusion first which is that the 2.4 might well suit your needs better due to what may be your fairly small space.
The CS5 has individual drivers, which at 8’ don’t integrate their soundfields very well. Also, the primary advantage of larger speakers is to fill larger spaces with deeper bass and higher amplitude. The 5 will do that only if you have the proper amplification to drive them, which as you’ve read here is a very big deal. The 2.4’s upper coax tolerates listening at any distance without compromise. The listener is freed from the triangulation necessary for individual drivers to integrate.
Another trajectory is that as Thiel and in particular Jim learned more he developed more sophisticated drivers. The CS5’s only driver from the ground up is the UltraTweeter. The ’i’ designates ’improved’ and adds copper motor shunts to the 3 woofers for significant bass improvement. The Focal lower and MB/quart upper midranges are very good stock drivers having none of Jim’s innovations. I’m saying that the 5 is earlier on Jim’s journey and as such the drivers are more ordinary. But, if you are filling a large space at full amplitude, the 5 puts out much more sound. Unless, of course, you can’t handle the power in your room.
There is another aspect that matters a lot to some people, myself included. The CS5 has true sealed bass. The transition from midrange to bass (down to 10Hz) is true first-order phase and time coherent bass. It acts like a real acoustic instrument in your space. The 2.4 is a very well executed reflex bass system using a passive radiator. The transition from the upper bass (woofer) to the lower bass (passive) at 24dB/octave (4th order) introduces a full cycle of delay in the sub bass - more than 20 feet behind the upper bass. That alignment has become acceptable in nearly all speakers, even costing $6 figures. But it is less authentic than first order sealed bass.
My studies in audio neurology suggest that the brain builds audio understanding from the bottom up. And therefore inserting the timing discontinuity between deep and mid bass consumes effort to decode and suspend judgement regarding the error. Again, the 2.4 bass is about as good as reflex bass gets, but it’s still reflex bass.
The 2.4 is easier to drive than the 5. Reflex bass eliminates current draw in the deep bass because the bottom octave is supplied via tuned mechanical delayed resonance, not a driver motor.
A pair of 2.4s might be found at under $1K. And a stellar and affordable upgrade path exists because there is no electronic crossover between the midrange and tweeter. The 5, on the other hand has 4 electronic crossovers, each far more complex than any of the 2.4 circuits because the later 2.4 drivers behave better, needing less correction than those in the 5 / 5i.
Tom T
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Beetle - our project was good both ways. Thank you for your careful and complete evaluations and reports. Even though we both think that you got seriously upgraded performance, there are actually big gains to be attained with less expenditure. One of these days I hope that you'll try out the next round.
I know it's been a long time - but things are coming into focus.
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devin - Replacing like with like components is certainly the safest. Many folks underestimate the intricate co-dependence of all the elements. Even layout changes affect the subtle outcomes. Keeping values at original levels is a good start, but various parasitics also matter. The frequency response is rarely changed in significant ways; but time/phase generally is.
You may remember the maddening months to years delays between Thiel product announcements, or even live displays, and their actual release. Most of that time was tweaking, mostly in realms more subtle than most designers would pay attention to.
In our DIY / rework world, the largest trap that I’ve found is subbing foil for the original wire inductors. Foil is indeed a more pure inductor, but its parasitics are so different from wire that considerable xo tweaks would be required to re-settle the circuits.
The safest bet is subbing in Mills MRA resistors for Thiel stock. Another safe and surprisingly effective tweak is replacing any electrolytic cap with 2 x half-value cap. The ESR and other anomalies are reduced by half, plus if you turn one cap backwards, end for end, other anomalies are cancelled. If there is a bypass cap (like Thiel’s yellow 1uF), that can be stacked to make a triangle for a single field.
Replacing caps, especially larger values is quite costly and sometimes demands circuit tweaks. It’s not hard to throw as much cost into upgrades as the entire production budget of the original speaker. Not for the faint of heart.
TT
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Devin - Thiel crossover schematics state the max tolerance of each cap. Some are 5%, some 10%. Among the strategies, I prefer to try for close to equal values when splitting. I've learned end-reversal via trials. E-caps are fundamentally symmetrical, but in fact the small differences, including lead-wire directionality, are audible and supported in the measurements. Music signal is AC, so optimizing for either direction produces mixed results; splitting directionality is always superior.
By the way, Thiel's long-term cap brand was Solen. Their house sound is somewhat dark and smooth. We later went to ERSE for a more neutral, open signature. When they became unavailable, M.D.L (Taiwan) was chosen. and the final FST (China) cap was CYC. I use M.D.L from Madisound for classic late-Thiel signature.
My new layouts honor propagation waveform integrity. When splitting any cap, build a bundle that makes sense. If 3 caps, I build a triangle separated by cork pads, with the 1uF bypass in the middle of the bottom row. Air circulates through the whole stack. A unified field is floated around the 4 cap bundle. Trials prove this arrangement superior to other layouts. By the way in series feeds, the yellow 1uF Thiel bypass cap is replaced with our new multi-sectioned cap with multiple coaxial windings that start around 0.015uF and add up to the target value. Those will be available in 2025.
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gmosley - first pass is to try Rob @ Coherent Source Service.
Next pass is to know that a group of us are working on upgrade packages of parts and implementations for existing classic Thiel products. The CS3.5 is on the A list. New grilles will be made similarly, but out of much stronger materials and incorporate better diffraction reduction techniques. At this time, you might consider simply filling the top and side edge steps of the baffle with plumber's putty, play dough, etc. to reduce diffraction and listen without grilles.
Of, of course, scare some up from Rob.
Did you get the Equalizer?
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No schedules yet. But I can tell you that the SCS4 has been our development workhorse for over a year and therefore will be first in line, including re-balancing for stand-mount use, plus our own stand that can accommodate outboard crossovers.
All - we're working behind the curtain and will notify you all first when things get more real.
Thanks for your patience.
Tom
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thieleste - I concur with vair68robert - Cardas is a good, albeit expensive, solution.
Background in brief: Thiel discovered its 18-2 x tight twist in teflon via aerospace, and solved otherwise insurmountable problems developing the 1978 model 03. Phase/Time coherence brought many system shortcomings into bright focus and ordinary wire was a big limitation. That 'Thiel' wire withstood all comparisons over the decades: 1988 CS5 development where we compared all the available contenders, and again Jim’s 2006 CS3.7 Swan Song design. From Thiel’s perspective and value assessment, it couldn’t be beat.
I began my own Thiel assessments in the mid 20teens and got serious in 2018. My scrutiny operates a little differently in that my value equation assumes product ownership, so further investments become incremental and more affordable than in new product bill-of-goods. I was aided by all the wire/cable heavy hitters and have learned more than I thought possible, especially in the domains of wavefront propagation integrity, and who understands what and how. My studies and progress landed with physics and quantum states, in which company ’it’ all makes as much sense as one’s skills can digest, interpret and apply. Deepest, longest rabbit hole of my life.
In our present context, the only ’stranded’ wires that pass muster for me are those that somehow insulate strand from strand - which are typically called 'solid' even when very small. Those include Cardas, some Kimber, Morrow, Anti-Cable and Iconoclast. (And possibly others I don’t know.) Many of the geometries are quite complex and expensive, and very good. New Thiel's 16awg - stranded is a big backslide, which often happens in the Dr. Toole frame of reference of ABX and things only matter if provable under their parameters and testing protocols.
My (upcoming) Renaissance wire family incorporates everything I’ve learned and painstakingly proven in the lab and listening room over the past 7 years. From my perspective of ’do no evil’ and ’preserve everything’, it nails it. And it is relatively simple and accessible - and therefore affordable.
Summary: Wire matters. There are more ways to go wrong than right. Low frequencies act differently than high frequencies (beyond current capacity). It you want to replace wire, investigate the brands I’ve mentioned. If you want to wait for mine, I really expect it to be available this year as ICs, Speaker Cable, internal hookup, chassis wire and coils. It stands on the shoulders of Thiel’s classic wire, which in many ways is already best of form.
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gmosley - Room placement is an art of its own. This forum can guide you to literature / information on that subject. Thiel products are wide-dispersion transducers, so try to keep them away from side walls or treat the walls more so than with many other speakers.
Thiel’s grilles are multi-purpose. In addition to the aesthetics, they also fill the edges of the baffle to reduce diffraction. Better if you use them.
The EQ extends bass to about 25Hz - worth the extra pair of interconnects.
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- I’m brewing the tea we started those several years ago. It’s getting richer and stronger.
Among the many lessons learned were real developments in wire and cable. You and I both like Cardas; very well conceived and executed designs. But with considerable complexity and cost. I learned from senior wire designers that to work optimally, the design must be worthy, plus everything must be executed to perfection, and the connectors to even higher perfection.
I suspect that a big part of what you like in your Cardas conversion is the PBP posts. Any of you who have those big-lug Thiel binding posts like on the CS2.4 can run an experiment. Put locking bananas on your cables. Try the inexpensive WBT / angled, stackables from Parts Express. Remove the knurled post nuts. Plug the bananas into the banana jacks. Listen and report back.
Ruminate on that and consider the GR-Research Electra Tube Connectors.
Small progress every day.
Tom
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Biwire is a special case. There are theoretical and empirical advantages. I've gotten good results with internally-biwired cable (in the same jacket). Problems arise with separate runs that the speaker designer can't control. An individual can evaluate including their own preferences. Also, there are upsides to single-wiring including avaialbility of all the conductive cross-section for big transients. Etc. etc. etc. Wire is a maze as well as amazing. Tom
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Massimo - The early 3.5 tweeter feed used a 6.5uF feed cap. It was tweaked in 1987 to 8uF, which is what you want. Only buy now if you need it. I will have a much better replacement soon.
The 3.5 mid and tweeter are front-burner projects. We are incorporating late-stage design elements into the 3.6 midrange platform - dual cone, advanced motor, to fit the CS3, 3.5 and 3.6. The 3.5 tweeter is obsolete and our replacement will also incorporate late-stage advancements to fit the CS2, 2.2, 3, 3.5, 3.6 and 5. Completion of midranges and tweeters is necessary to re-work the crossovers between them. For now, get your advice from Coherent Source Service.
The ScanSpeak 10F8424 is not robust enough; it will burn out. SS’s recommendation for drop-in is 12W/8524G00. CSS may have that driver or another of their choice.
Tom
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