I just scored a sweet pair of CS 2.4SE loudspeakers. Anyone else currently or previously owned this model? Owners of the CS 2.4 or CS 2.7 are free to chime in as well. Thiel are excellent w/ both tubed or solid-state gear!
In response to pieper1973’s query about home-brew cables, I thought it might be fun to recount my escapades over the past couple years. As you know, I’ve been re-evaluating classic Thiel products for upgrade opportunities and have reported many here. I’ve also reported my semi-blind method both solo and with single or multiple assistants: A & B ’whatevers’ are made by me, but the label of A or B is assigned by someone else, who remains wholly blind while I am half blind. First pass is to play any mutually-agreed track and take notes - any notes of any kind to discuss in any terms. Second pass is to reveal ’what’ we are listening to (which might be mechanical, electrical, source, driver, cabinet, wire, room, etc. - anything. Then play A & B again with notes and sharing. Third pass is to share any measurements or background that I had previously developed and, depending on available time, listen again. These sessions are enormously informative because the feedback is any blend of musical, technical, relational, comparative, etc. and these flights of exploration provide avenues of engagement that apply to all the work, not just the system presently under test.
Through 2019-2021 I’ve spent hundreds of hours comparing hook-up wire, while tapping the extensive listening / testing that Thiel Audio performed during the CS3.7 development, as well as my experience developing the original aerospace-inspired classic configuration, and with special thanks to Steven Hill of Straightwire, Thiel’s long-term wire partner, who has been enormously helpful with samples, information, reference materials and sharing his decades of experience. A hardy handful of commercial wires were compared to classic Thiel 18-2 CDA101 (slow-drawn) in teflon twisted at 3/inch. In shorthand, classic Thiel "won" due in part to having been part of the intricate engineering puzzle for the speakers under test. 4 CS2.2s were used in the early stages.
Enter plan B - a different speaker. I was re-assessing First vs Second Order topology via the SCS4 as the second order, coherent entry. By its coincident driver geometry with the tweeter set-back the correct amount, Jim created coincident time arrival and smooth phase transitions while sacrificing only the amplitude of the phase swings through the crossovers. I created two pair of quasi 02s using CS.5 drivers and (modified) crossovers for functional twins where the only difference between A & B was first or second order, respectively. Long story short, I am re-committed to first order (net roll-off outcome) slopes for reasons too complex for this posting.
My wire comparisons got easier using the first order 02s with 1’ sections of wire to the woofer and tweeter from the separate external crossovers. With first order XOs, differences of 1’ of wire could be readily heard whereas with second order, they could not. My suite of measurements also showed differences, sometimes clear, sometimes clouded by ignorance or unknowns - but nonetheless experientially real and correlatable.
Onward to results - wire is extremely complex and functionally impossible to sort out what is "best". My criteria include doing no harm, adding or subtracting no color, texture or character, introducing no measurable effects and offering greatest musical engagement.
I’ll note that I have not explored flat wire such as Goertz. Note also that Goertz is where Jim ended for driving the CS3.7, while retaining ’classic Thiel’ hookup wire.
Highlights:
A) + and - leads are best when identical and integrated in a single run. Note: the signal is AC and integrated. Separating runs introduces asymmetry.
B) Insulation matters. I ended with ’teflon’ family insulations, despite their high cost. Note: I am enamored with cellulose (cotton, rayon, etc.) with possibly lower dielectric absorption than hydrocarbons. (In dreamworld, I land on nano-cellulose for use as insulation, in caps, and driver diaphragms.)
C) twisted pairs in right-twist, left-lay configuration wins. Note: I tried counter-lay, various parallel lays, braids, coax etc. Twist is 'perfectly' executable via reasonable means.
D) Larger gauge doesn’t quite win. Contrary to common sense, lower resistance isn’t the only game. Larger wire gauge exhibits different characteristic impedance. 18 gauge is uniquely suited to audio frequencies.
E) Stranded sounds different than solid. I reaffirmed solid as more correct, but also less forgiving as is often attributed to Thiel speakers. I didn’t like the slight tizzy HF veil and slightly wooly LF fumwp of stranded wire.
I sorted out mechanisms (that satisfy my particular problem-solving approach) to account for perceived differences.
I have a resultant wire configuration that I’m willing to share with interested collaborators on this forum. My apologies to whomever I left hanging during my present shut-down to close up my shop/studio. PMs are appropriate.
Hello all, picked up my fourth set of Thiel, a pair of CS 2 3 with upgraded tweeters from what I can tell from a previous receipt with Rob @coherent. Unfortunately the serial numbers are gone on these, but they are in excellent shape with exception of a few spots on the grills. This leads me to my next question, has anyone redone the grill fabric on this newer style that has excess material to compensate for the larger baffle area?
Also own the 3.5 w/eq, CS 2 2 and 1.2 - thanks in advance
@vair68robertat the moment I have a silver line cable from Oehlbach. I also have a no name cable which I had made for connecting my mono blocks to the Thiels.. I still have that cable. Might give it a try..
I have a few foil types I would sell. I have replaced the foils with 49 strand Litz wire in my most current speaker rebuild consisting of Purifi and Via Wave drivers and outboard crossover. PM if your interested in these foils. TomD
I am using speaker cables I made for the negative and both ends of a pre-made for the positive . I used Cardas chassis wire to made the cables for both the pos and neg , while at first I like the extra slam they gave me over time I realized that they were harsh or grainy on the upper end so I repurposed them to be used on the negative side . The sound is fantastic compared to just the Cardas Neutral Reference alone .
You can check out an image , use Thiel as the tag and my system is about the last one .
Hi Tom! Thanks for the info about the CS3. I will contact Rob so see if he can send me the dampening compound for my CS3 woofers. In case you are curious, I also have the CS2.4 (upgraded coax) and the CS2.7. Sadly the CS2.4 and CS2.7 are in there original boxes because I am going to move soon. Let me know when you have the updated bass equalizer for the CS3 and I would gladly purchase one from you! Thanks,
biannuzzi - here's some background that might be useful.
The CS3 and its replacement the CS3.5 share the same enclosure volume and woofer, except for addition of an applied damping compound to the 3.5 woofer, which you can get from Rob. In my opinion, the quality of the native bass is superior to any subwoofer, unless you drive it very hard in a big room and need the sub. That's the purpose of the 40Hz bass cutoff. FYI: the unequalized -3dB point is 80Hz, falling at the sealed box 12dB/octave for critically damped, authentic bass response. If you have or ever get a 3.5 equalizer, it has the same CS3 parameters, but better circuit design and implementation. I will have an improved EQ later this year.
Many integrated amps have a 'tape loop' for sending a post preamp signal to be recorded (or equalized) before returning to the poweramp input. The equalizer can be inserted into that tape loop with some small signal degradation.
I think someone was referencing the CS3s on this forum and about the bass equalizer. I have a pair of CS3 and I love them! When I purchased the CS3 they came with the bass equalizer but it quickly died on me. I purchased a brand new one from Rob and I haven't even use it yet! That is because I also bought a Thiel SS2.2 Subwoofer with the PX05 passive crossover. Buying a nice sub would be a great alternative to buying the bass equalizer. It can be tricky trying to find an amp that would allow the integration of the equalizer, especially if you have an integrated amp. In the future I am planning to purchase a preamp and a power amplifier and just stick the equalizer in between them with RCA cables. When the bass equalizer is incorporated into the system there is a noticeable increase in bass!
When I completed building the xover boards, I let it run for 24 hours with a dummy load for the components to settle then hook it up to the speaker drivers. At first, it sounded like a AM pocket radio, after a few hours play time, sound quality keep improving until about 100 hours then the SQ become stable and the sound open up with a holographic sound stage... YMMV!
My L5 inductor (ie, the one on the coax board, paralleled with 28 uF cap and 2 ohm resistor) is Erse FoilQ, 16 gauge, 0.15 mH.
I have all Mills MRA12s, the 30 ohm position I used paralleled 60.2 ohms for improved cooling.
The biggest difference I see in your pics compared to my build is that I have full capacitance in single caps. I *greatly* benefitted from tagging along with @tomthielas he explored his “renaissance” project. Not to mention his considerable coaching.
All main caps are Clarity CSA. Coax feeds (14 and 28 uF) are 630 V, subfeed (43 uF) is 250 V, and shunts (100 uF) are 100 V. Each of the feeds and subfeed are bypassed with Multicap RTX at just under 1% (eg, 0.1 uF on the 14 uF cap). The shunts are bypassed with the 1 uF yellow caps common in classic Thiels (Elpac?).
That said, Your use of paralleled CSAs (eg, 18+10) should be fine, certainly not worse than the original CS2.4 which used 27+1. Best wishes resolving the issue.
[edit: post number 11111. Look at what you did, @jafant!!]
@improvedsoundAssuming all values match OEM and the connections are consistent with the schematic, that board should be singing. From your images, I see nothing out of place although I can’t see everything. Total resistance of the coax board should be, IIRC, 32 ohms. If all values and connections are good, that suggests the foil coil is the culprit. I also put foil (Erse) in that position, would have to dig into my notes for the gauge.
Could also be you just hear things differently than I do. But there are now at least 3-4 of us who modded at least the coax board on CS2.4 and reported good results. I suggest verifying all values, connections/layout, and total resistance. If those are good, put the OEM coil into that suspect position.
improvedsound- you’re in the deep end, so take care.
My knowledge is anecdotal and experiential. I have experimented with foil inductors enough to learn that I’m over my head. Indeed a foil inductor is a more perfect inductor than any wire inductor. However all components exhibit all characteristics ie, an inductor also has resistance and capacitance plus the products of reflectance interactions between them - and time factors as these interactions play out. So, changing anything changes everything. Flash back to my direct observation of Jim’s learning curve about these matters, as each iteration of each product grew into its maturity. Part of that advancement is about understanding and implementing more aspects of such component interactions.
There are direct aspects that can be adjusted. A foil coil will have much less series resistance and different capacitance characteristics in space and time per equal inductance value. In some cases those changes can be corrected via addition of a series resistor and/or layout changes to compensate for circuit capacitance and resonance variables. I have been able to accomplish some of these requirements in my experimentation and coaching. However, I’ll say it again, I’m a novice and not qualified to re-engineer Jim’s work beyond basic changes.
So I keep the extant inductors because I know them to be best-of-form (at any price), providing an anchor for any other circuit changes. Similarly with caps, ClarityCap provides very predictable performance in all measured aspects - it’s no accident that they are an industrial / aerospace / professional company making products based on solid engineering performance. (I have tested and measured some brands that de-spec some aspects to achieve some euphonic outcome.) A person could spend a lifetime making sense of the correlations. I’m keeping it simple enough for me to make sense of it within my constraints.
Regarding resistors - the Mills sound better than Jim’s. Fair enough, they cost 5x as much. Jim developed, from first principles, what is called the Ayrton-Perry winding which is non-inductive with minimal parallel capacitance within an inexpensive sand-cast case. His circuits and layout assume those A-P characteristics. I know that Mills MRA-12 is a direct drop-in with the same characteristics. However, I don’t know much for certain about Path, or film or bridges. I do know that altering the type of resistor or any component will have effects that are sonically important. I also know the hundreds, perhaps thousands of hours learning by listening and integrating with fundamentals of physics to get the holistic design expressed in each product as designed.
I do not have the knowledge to help unravel what might be going on when some component is changed. I do know enough to be extremely cautious and make changes that don’t screw anything up. I do not deny that some folks have gotten results they are quite happy with, but the system is complex enough that a dose of luck could be operative. So for myself, caution wins. Trust your ears. If something sounds "off", call it off. Then the fun begins putting Humpty-Dumpty together again.
This very long answer is to recap territory we’ve explored in these 223 pages over that past few years, which new participants probably haven’t read. Keep the faith, learning is good.
@beetlemania For the bypass I have used the 0,1 uF Miplex KCPU
But .... i have doubts about the inductance.
Despite the human voices are improved I think that the Jatzen inductance, situate on the output, - you can see in the picture- have changed the performance in worse
Now, I no longer listen the same depth, holography and linearity in the global sound emission. It is like listening a hump, between the medium-high and medium-low frequency cross, while the sound is projected forward
Dear @tomthiel what do you think about it? I am really worried
That looks really nice! Great job. Curious what brand/model is the 0.1uF bypass?
I would have elected to also use CSA for those 100uF shunt caps but I know those are very large and expensive. That way you get away from electrolytics and their propensity to drift with age and it’s quite possible they sound a touch better, too.
I've been reading this thread for some time. I was encouraged to improve the performance of my beloved Thile C2.4.
I started working on XO and I thought about putting them externally. This is the preview of my work.
“The [Cs2.4] crossover can be accessed through the passive radiator opening. The base is not removable, as it is screwed, and glued. To access the crossover, you must remove the passive radiator screws and let the passive radiator drop into the cabinet. It can be rotated 90 degrees, and removed while servicing. To re-install the passive radiator, you can place your fingers at the surround, pressing outward to hold in place while re-installing the screws that hold bit in place.”
It is not glued but it is a bit of a puzzle to orient properly to get it out (and back in).
The pure by clarity caps is not being produced in 14 and 28uF.
I've sent an email asking if they would do custom made caps and will let you know if they do...
On a somewhat sombre note.. I've managed to kill one of my coaxes (SCS3-N) 🤦🏻♂️
I really do hope Rob at coherent sound can either fix it (those units were 700 Euros a piece at the time) or fix me up with a new unit as he already has with the SCS's..
All the parts are ordered and/ or one the way, but this little accident is going to delay things a tad..
I'm not concerned with how big the capacitors will turn out to be, as I'm not going to stick them back in the cabinet. They will be fixed on a board, outside the speaker, with a bi-wire coming from the board into the 2.4: for this I'll need to put two more terminal posts at the back..
For fun and a further learning experience you should try replacing what certainly appears to be steel fasteners holding your crossovers in place. I would do only 1 at first as my guess would be an imbalance left to right. Probably need to settle in for 12 or more hours. If you do hear an imbalance or change in response then do the other speaker to match.
My preferred fastener is brass a non ferrous material.Steel will bend the intended field of flux.
I did this 20 uears ago replaciing steel fasteners with brass in and around the crossover of my Dunlavy SC4.. Then replace the cast resistors for Mills or Path for simple and quality upgrade. TomD.
jazzman - you should be fine. It seems most of the "difficult period" might have been 2003-2004. Thiel probably found better sources, plus China definitely improved its development and manufacturing chops year on year.
The the tell-tale test is looking at your boards for the winding quality of the coils.
The pictured XO looks just like mine. If 2951-2 look like that, they're from the same era. Those black caps are polyester-mylar (one down from polypropylene), the coils are well-made from CDA-102 wire, which is high-end regulation wire, one step down from Thiel CDA-101, which is the best available. I tested these resistors and found them to be the non-inductive resistors that Jim had designed and made by ERSE. Although they look like normal sand-cast, but are better. Note that these PCBs are actually point to point layouts with no traces that can cause troubles. This wire has Thiel signature teflon insulation. All in, I would be happy with these boards, unlike some we have seen with obviously poorly wound coils and unknown insulation.
That said, if you're DIY-inclined, you could elevate the sonics by upgrading all resistors to Mills MRA-12s and all film caps to CSAs with the 100uF electrolytics to some upgrade recommended on this forum. I have eliminated all electrolytics and have developed an affordable CSA-type 100uF cap that works well. Not ready yet.
I don't want to open Pandora's Box regarding product iterations and quality levels. I'm told that all 2.4s were assembled in Lexington, approved by Jim and tested to the historical standards. I have expressed my personal disappointment that some particulars of parts quality eroded after my watch. But, compared to competitive products in design and execution, I suspect Thiel stayed way up on the value charts.
My Thiel CS 2.4s are serial# 2951 and 2952. Purchased pre-owned from Audio Consultants. Speakers were approximately 5 years old at time of puchase in April of 2011, with 5 years remaining on the warranty. So presumably manufactured some time in 2006. So with respect to the boards and parts, where does that leave me?
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