Thiel Owners

So my dilema is do I upgrade the 2.4's to 2.4SE's as I can get the upgrade kit from Rob and be content with my current system or do I sell the 2.4's and the SS2( hopefully to someone who loves Thiel and appreciates the quality) and get a pair of 3.7's?

The sonic part of the SE "kit" simply replaces the 13 uF polypropylene + 1 uF styrene bypass with a 14 uF Clarity SA and the 27 uF PP + 1 uF bypass with a 28 uF SA. Those are the coax feed caps and SA's were chosen by Jim Thiel and Gary Dayton as the best sounding circa 2008.

But there are better caps available now (eg Clarity CSA) and other passive parts (caps in other positions as well as resistors and coils) can also be upgraded. That is what Tom Thiel is working on. If all goes well, this "super" upgrade kit will be available from Rob Gillum by the end of the year. If you decide to keep the 2.4s I advise waiting for the more robust upgrade kit. "Just" upgrading the resistors made a very nice improvement on my SEs and I suspect the full upgrade will bring the SQ to the next tier.

That said, if you have the coin I recommend the CS3.7 which has better drivers and cabinet than the 2.4. And Tom Thiel might have an upgrade kit for those boards, too, although the time line is further out. I suspect a tricked out CS3.7 would be sonically competitive with some of the very best speakers out there.

Your recollections and future considerations of the CS 5's is most interesting. Perhaps my favorite Thiel model. If it weren't for the associated amplifier demands, I'd probably own a pair.

IMO, the ultimate Thiel would have the 5's sealed bass, the 3.7 coax, and Tom Thiel's optimized passive parts . . . and more amplifier friendly impedance. *That* could be a crazy good speaker!

Turns out...I like my Thiels better :-)

Hmmm, what will you say should you upgrade your crossovers? 

I will do soldering soon by myself, but kind of worrying about my soldering skill will mess up the 7.2 or not. Although Rob told me that's straight forward. 

Then you will have the confidence to upgrade your caps and resistors or build a full “hot rod” kit if/when it becomes available.  :)

Magico Q7 Mk II. They are $223 K

I’d like to think these would outperform a $15k speaker! But the SQ gap, if any, is not anywhere near the $$$ gap. All the more so if the crossovers are upgraded to premium parts. Maybe some of you CS3.7 or 7.2 owners will try Dueland or Path resistors. Anyone wanting to explore the outer limits with Dueland caps, however, will certainly need to go outboard (see Jim Smith’s outboard 

http://jeffsplace.me/wordpress/?p=5464). In the meantime, Tom Thiel’s parts choices will be significant quality upgrades while still in line with Thiel Audio’s performance/price sensibility.

what was your trade/occupation prior to joining Thiel Audio in th mid-90's ?

You've misunderstood. Tom Thiel *founded* Thiel Audio with brother Jim and Kathy Gornik. Tom left in the mid-90s.

In a holding pattern for now. Tom Thiel should get the custom Clarity caps by the end of the month. I do have my Multicaps now but don’t plan to use them until I build the new boards. In the meantime, I hope to identify any substantial cabinet resonances. And I’m enjoying the SEs with the Mills resistors. Probably the most cost-effective tweak I’ve done.

@vair68robert

Sounds like you have a solid plan for an upgrade path and Tom might have some ideas for you. Here’s my two cents.

Do you have the schematic? If you’re on a budget you should target the parts in the feeds, rather than shunts, and prioritize the coax filters over the woofer (CS2.7 has electrical XO for the coax, right? CS2.4 coax is mechanical). That said, I was able to hear a difference among two voltages of otherwise identical capacitors in the woofer shunts, so *everything* should be assumed to make at least some sonic difference.

I recommend replacing as many resistors as possible on both boards as this makes a nice sonic difference for relatively little cost. Some of the CS2.7 values cannot be matched directly with MRAs, you will have to get creative with parallel and series replacements to get the correct resistance and power ratings. I noticed that PartsConnection has better pricing than Sonic Craft right now.

Clarity Cap CSA is a great sounding cap and a good value. Higher voltage has thicker film and this is desirable for the midrange where our ears are most sensitive. The downside is higher voltage caps are larger and more costly. CMR is said to be a step up from CSA but I haven’t heard these. You might also consider a bypass (1% or less total capacitance) on coax feed caps. I used Multicap RTX and heard an improvement in transients and, maybe, improved resolution. I was curious to also try CMR (Tom offered that as an option), Audyn True Copper Max, and/or Jupiter copper foil as bypasses. I dropped those plans after I put in the Cardas which just put the “cherry on top” of all the sonic improvements I heard along the way.

A couple of other things you might consider . . . 1) electrolytic capacitors will drift with age and this type is sonically inferior to film type, even if in a shunt position. The downside is replacing ELs with film is costly and requires far more space. You would need to make an entirely new board to replace that 400 uF EL with film caps. 2) Foil inductors are said to be an improvement over coils. I have ERSE FoilQ in the feed paths for both the coax and woofer boards. I did not make this particular sonic comparison, however, because I replaced the caps and inductors together.

Finally, Tom had cautioned me that such wholesale replacement of parts could upset the sonic balance in unpredictable ways and that one check was to compare the total resistance of the circuit before and after. I didn’t do this until after I replaced all the resistors but my final boards are within 2% of both the OEM boards with Mills MRAs and the values on my copy of the CS2.4 schematic (the CS2.4 woofer filter is almost a flow through, <1 ohm).

I am looking to improve highs which sometimes lack crystal clear clarity, I think the technical term is "tizzyness?" Also would like to improve the vocal/midranges, make these warmer and deeper. What should my next upgrade be?

Upgrade the crossovers!

Seriously, this will be your best bang-for-the-buck move and I imagine you will be very happy with the result. Tom Thiel has an idea regarding “tizzyness” and Thiel’s reputation, among some, for being bright despite the ruler flat measurements. Unfortunately for you, Tom is not currently planning an upgrade kit for CS2.3, partly because of lack of demand for that model (as measured by responses in this thread). But maybe your need will spur him?

If you can’t wait for a kit that may or may not ever come, you can start your own upgrade. I have replaced the OEM resistors in my CS2.4 SEs to notable improvement with Mills MRA-12s. Highly recommended. I will build entirely new boards later this summer/early fall, replacing all parts. My SEs are something of a test mule for Tom’s kit development.

Tom may chime in with some ideas for you but feel free to PM me if you want more details about capacitor choices. The CS2.3 boards are roughly similar to those in my 2.4s, a bit simpler, even. The main unknown, for me, is how much room you have to replace the 100uF electrolytics with film caps. You can probably otherwise directly replace the extant caps and resistors with higher quality parts.

The result should be amelioration, if not complete removal, of the "tizzyness" and notably enhanced clarity and transparency. Jim Thiel engineered some superb drivers - these merit higher quality passive parts!

@thosb Did you receive my reply to your PM re: caps for CS2.3?

@vair68robert Thanks for posting pics of your CS2.7 crossovers. Fascinating to see that compared to my FST (China)-sourced boards that were OEM in my CS2.4SE. Yours are point-to-point on Masonite compared to my PCB (@tomthiel says PTP was the Thiel protocol for most of the company's history). Also, your parts quality is definitely higher than my OEM boards. Other than the excellent Clarity SAs on the coax feeds, I had CYC MKT (polyester!) caps, loosely wound coils, and unlabeled resistors. But I was probably most surprised to see that multi-strand hookup wire on your boards (reminds me of what I used for speaker cabling when I had a mid-fi system). My OEM hookup wire was solid core (18 ga) the + and - wound to 3 twists per inch. Tom told me that was the Thiel standard. Your boards seem to be a quasi Frankenstein of classic and new Thiel (mostly in a good way!). I wonder if yours are typical of all CS2.7.

But my Tom Thiel-designed boards are a whole 'nuther level! If you're inclined, you might play with upgrading the parts quality on your boards. An easy and affordable place to start is to replace those sandcast resistors with Mills MRAs. I replaced all of my resistors for about $100 - that was my first upgrade before the full rebuild.

@vair68robert

Looks like at least one 25W resistor on each board. That 2 Ohm on the coax board could be replaced with parallel 4 ohm Mills MRA-12s. That would yield a 24W rating. Close enough, I think. The CS2.4 has a 30 ohm resistor on its coax board. Tom had me use parallel 60 ohm for more surface area and improved thermal management. I bought mine from Sonic Craft. Had to mix and match from the older Mills and newer Vishay Mills to get the proper values at each position. Mine are all 12W versions, OEM sandcasts were 10W, so I gained a spot of headroom.

There are well respected amplifiers that don't double. Ayre, for example.

Ayre doesn't give a 2 Ohm spec but not sure why you wrote this. Ayre specs *all* of their amps as doubling into 4 Ohms. The AX-5 JA measured did show signs of stress at 2 Ohms but otherwise reacted well as the current demand increased on his test bench. I have the Twenty version of the AX-5 which is said to have slightly improved power over the original version and I will attest that it sounds really effing good driving my CS2.4SEs  :)

@jafant I don’t have an SPL meter. I can tell you that I don’t listen at ear-piercing levels. I used to use an AX-7 to drive Vandy 2s and I could get that combo to clip but only at levels too loud for me. My room is ~18x19 with a vaulted ceiling 8-12’ (plus two large openings on the rear wall). I have yet to hear the AX-5 clip with the 2.4s. If you like the Ayre sound and want more power you can move up to the VX-5 separate or a used V-1. The MX-Rs have even more power and should drive pretty much anything but you better come with deep pockets!

@prof How often do you swap connections? Spade connection is tough to beat for a solid transmission of the signal. Set it and forget it. 

break-in is something that many engineering-oriented observers dismiss as voodoo or make-believe or user acclimation. From the very beginning, we perceived its reality beyond question, but have never developed any definitive causal narrativeeyond question, but have never developed any definitive causal narrative

Yes, thanks for sharing this perspective, Tom. I completely agree. I’ve experienced break-in not just from speakers but from electronics and, even, cables. Just because we can’t explain or measure it doesn’t mean it doesn’t happen. 

@stspur I built completely new boards for my 2.4s last year, with guidance from Tom Thiel. Excepting for a few bypass caps, everything is Clarity Cap CSA. Higher voltages on the coax feeds. Even the big 100 uF shunt caps are now CSA (low voltage). Jim Thiel and crew picked the Clarity SA for the 2.4 SE out of several compared. The CSA is an upgrade from the SA. Also, the CS2.7 includes some Clarity caps, maybe ESA which is between SA and ESA.

@vair68robert 

I switched back to the parallel ++/- - configuration a few days ago. I do hear this as more open and dimensional, less bounded. Could I pass a DBT? I dunno and I don’t care. If I were more motivated I would compare in mono. But that requires removing the outriggers and spikes and a couple of hours of swapping speakers back and forth. I’m not saving the world here, just maximizing my enjoyment. 
Now, I need to decide whether to resolder the binding posts so that the cables are not off the ground as much. I will not be enjoying anything if a house guest trips over the elevated cables. 

I'm less inclined to try the expensive Ayre

Just from the price points I wouldn’t think to match MXRs with CS2.4s, but I bet they would sound fantastic. Even more so with a Tom Thiel modded crossover. To repeat what I’ve written elsewhere in this thread, I suspect a modded 2.4 will compete sonically with other speakers up to $30K. 

I have two levels of upgrade specified for each of those first two products. 

Hi Tom
sounds like your plans keep evolving. Can’t wait for a report. Didn’t know the Cornell Dubiliers were back on your radar. Hope they don’t obsolete my RTX!

@tomthiel Thanks for your report. I’m impressed with the variety of configurations tried. I’ll further adjust mine based on your narrative. I wonder why “don’t do it”?

I was at least able to verify that the original caps are indeed Clarity Caps SAs as I am almost certain that this is the first re-cap these 3.6s have ever experienced

You must have very late production 3.6s. I would have guessed Thiel stopped making those before Clarity introduced the SA. Interesting. The SA is a good cap but, as Tom Thiel wrote, the CSA is a step up. The CMR is supposed to be even another step up. But those are much larger, possibly requiring a new board to accommodate their size and much more expensive. My new boards have 630V versions of CSA on the coax feeds. It would be interesting to compare 630V CSA to 400V CMR. There is a 630V version of CMR but those are bigger still and more expensive with a smaller range of available capacitance values.

You probably have high quality coils but I would replace any sandcast resistors with Mills MRA-12s.

Jim never went over 100uF.

Pic of @vair68robert coax crossover has a 400 uF EL. I know this crossover was designed after Jim passed. I imagine he will need to use an entirely new board if he chooses to replace that cap (plus a couple of other ELs visible in his pic, presumably >=100 uF). That would be quite the volume in film caps! But possibly worth it . . .

@last_lemming Soundstage/ultra audio and feel the music both reviewed the SE version albeit they did not directly compare to the standard version. The only difference related to SQ was two capacitors in the coax feed. These are Clarity Cap SAs which Rob Gillum has at Coherent Source Service. I think you will find this a worthwhile upgrade. But these have now been surpassed by two generations of Clarity Caps. 

This is a *really* long thread to slog thru but maybe start January 2018 when Tom Thiel started posting. Mr. Thiel is working on crossover upgrades for legacy Thiels and the CS2.4 is among the first models getting his attention. He is planning Clarity CSAs in the coax feeds, probably with 1% Multicap bypasses. Other caps are also likely to be CSAs including a custom low voltage cap in the shunt positions.

Resistors will be Mills MRA 12s. I replaced my OEM resistors with Mills. Here are my comments copied from elsewhere in this thread: “the Mills has a fuller, richer sound although my perception of this varied from song to song. I heard little, if any, difference on solo trumpet but a pronounced difference on the well-recorded 2L Mozart violin concerto. Guitars and voices were more "full-bodied" on folk-rock, blues, and bluegrass. More “tonally-rich” might be another way to describe it. On a Chesky test recording, percussions were more emotionally engaging, toe-tapping. The Mills also seems to have a bit more texture or, at least, it was easier to hear into the microdynamics. I think this is related to my initial impression of a "lower noise floor”.”

"I hear more bass impact, a more spacious soundstage, and, especially, an ease of presentation. The MRAs even seem to have mitigated a somewhat “glassy” quality in the midrange."

If you are itching to upgrade, get the SAs from CSS and Mills resistors from Sonic Craft. Otherwise, wait a few more months and get the full kit from Tom Thiel/CSS after the upgrade is finalized. 

The 400uF electrolytic is in series feed to the midrange. 

Oh, wow! Welp, on the plus side there is more room for sonic improvement. But 400 uF of film caps will certainly need a new layout/board. And it looks like one of the other ELs is 220 uF. And not only much bigger but also $$$.

My new boards were much larger. I compensated in the passive radiator chamber by removing a similar volume of the fiberglass batt. But I only had two 100 uF ELs to replace. 400+ is probably still doable but complicates the issue and makes the upgrade spendy. Clarity CSA 250V is available in 100 uF for $68 each. PulseX 250V is more affordable and should be sonically superior to ELs. Lean on Tom’s Knowledge, Robert!

@tomthiel looking forward to pressing my Multicap bypasses into service :)

@thosb only on reputation, i would rank them BAT>Classe>>>Sunfire. Good luck

Vandersteen’s carbon drivers are, IMO, the best audio drivers ever. If I win the powerball, I won’t look any further than his model Seven.

The 2.7/3.7 coax and ribbed diaphragms were a significant step towards the same goal Vandersteen has with respect to pistonic behavior. I’ve long considered Jim Thiel designed drivers to be among the best. Who knows what he would have produced by now. But Tom shared with me the concept of the CS7.3 and it would have a new pinnacle in the Thiel line . . . 10 years ago.

We audiophiles are fortunate to have had JT and RV bring their talents to our listening rooms with gear that we can actually afford. That their designs compete with or outperform others at multiple times the price is a testament to their abilities and real-world sensibilities. 

l recommend evaluating any amp (for Thiel speakers) by its ability to sustain a 2 ohm load. 

I’ve had great success driving my Thiels with Ayre. I used an AX-7e to drive CS 1.6s and am now using an AX-5 Twenty to drive CS 2.4 SEs.  The 7 is rated at “only” 60 W into 8 ohm and the 5 at 125, both doubling into 4 Ohms but neither has a 2 Ohm rating from Ayre. Both play plenty loadly for my tastes and room. I did get the 7 to clip when I pushed my Vandersteen 2s, which are considerably less efficient than the 1.6s. Still, that was at SPLs exceeding my personal comfort zone.

I guess I’m suggesting  a strict 2 ohm rating for Thiels might exclude some otherwise great amplification that will work just fine. Perhaps this should be model-dependent. Looking at the CS5 measurements, i probably wouldn’t mate an AX-7 with those!

I just ordered some Audyn Q4 capacitors to replace all the electrolytic one originally installed on my CS 3.6, in detail, four 100 uF/100v and one 66 uF/100V

That is fantastic, please let us know the sonic results. I suggest you also upgrade the resistors to Mills MRA-12s at the same time.

learn the 2 ohm behavior

Hi Tom, Stereophile has measured both Ayre models i have owned. Soundstage might have also measured the AX-5 but maybe it was the amp rather than integrated. Charles Hansen was not a fan of power ratings for amps. Here are some of his thoughts. Also, here

Edit - looks like my links don’t work. The short of it is he said you can’t predict how an amp will sound from its measurements. 

CS7.2 (and 3.7) is just behind the very best speakers I’ve heard, and at a fraction of the price. I suspect Tom Thiel’s XO mods will narrow that gap. I’m itching to finish my 2.4 upgrade. I suspect I’d have to get something like a Vandy 5 carbon to demonstratively beat it, and that’s a speaker well out of my financial wherewithal.

Geoff Kait is on the bleeding edge of tweakery but I don’t think he’s trolling or bilking anyone. There are many things in audio that can be heard but not explained. The human ear/mind is not the same as an oscilloscope or any other measuring device. Measurements are good to have but they cannot fully inform what we experience when listening to music (and not even partially inform the emotional part of our experience). Mr. Kait’s tweaks may be controversial but I would not dismiss them out of hand. 

Pretty much all designs have trade-offs. You can reduce, if not eliminate, them by throwing more money at it but real-world speaker design is a series of compromises. Sure, Wilsons can play loud as hell, but at what (sonic) cost?

The smaller midrange diaphragms in Thiels are much more rigid than those used in Wilsons. This is a function of both materials and size. The upside of Jim Thiel’s choice is that you hear far less distortion. IOW, a more realistic recreation of the recording, warts and all.

Other than the TAD Ref One with it’s largish coax (beryllium at that), all of my favorite speakers have midrange drivers <5” diameter. Tbf, ability to reproduce The Who at concert SPLs is very low on my list.

Regarding access to XOs for the 2.4, here are Rob Gillum’s instructions to me:

“The 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.”

I would add two things, 1) be patient rotating the radiator to get the right angle for removal; 2) you don’t need to be overly paranoid grasping the radiator surrounds as I was initially. Not nearly as delicate as I first imagined, albeit still need to exercise care.

@andy2 Other than the Clarity SAs in the coax feed, there is reason to think your Lexington XOs are superior to later iterations that were sourced from China. That said, you might still consider upgrading the components if not doing a full rebuild such as I will be doing soon. Stay tuned.

My early plans were influenced by some other threads here regarding aftermarket caps and, more substantially, by Tom Thiel's comments here. But other than, maybe the Mills MRAs, all of the current plans and component choices are from the mind of Tom.

I’m getting close to building the new boards. These will include Clarity CSAs replacing all extant caps, including eletrolytics. Tom has a custom voltage for some of these to save space and expense. My coax feed caps will include Multicap RTX bypass at about 1% of main cap capacitance. Resistors will be the Mills; I’m already running these and you can read my report in this thread maybe May, 2018. My XOs were sourced in China and the coils are suspect, so these will be replaced, probably foil in the coax feed. PCB will be replaced with point to point on masonite. Tom has written other details just a few days ago regarding his idea to provide cooling for resistors.

Thanks sharing that interesting history regarding Thiel and Vandersteen dealers, Tom. I’ve read most of those journals Hardesty wrote and edited and he was certainly a fan of both brands (and not a fan of Wilsons, Pipedreams, etc). You might look to his writings for amplification ideas. He was a fan of ARC and Ayre - hey, so am I - and I recall he liked VTL among tubed electronics.

I’ve heard both the CS7.2 and 3.7 but in different rooms and different electronics plus a few years apart. I cannot pick a winner but both were extraordinary, just below the very best I’ve heard (but at a fraction of the price). I probably sound like a broken record here but I think Tom Thiel’s XO upgrade could bring both models into that next tier.

 I disassembled one (original prototype # -0004) cabinet, removed the crossover and wired only the woofer to the input terminal. The other (-0003) was left as a reference with the internal XO and woofer intact, but with the midrange and tweeter disconnected. I built the woofer section for -0004 by the new layout while using all the original parts in the original orientations. No upgrades, changes or replacements to confuse the issues.

. . .

 #-0004 reference "A" exhibited splatting on every bass+drum hit. It would be attributed to amp clipping or passive radiator and/or woofer bottoming - overload / or just plain too loud for the material. But I didn't turn it down. On -0003 external XO "B", those same hits were audible, but not extreme, in fact they played more like "hard punch" than distortion. . . . Of extreme interest is that speaker A sounded like a woofer, somewhat woofy, lacking the detail one would get from the midrange and tweeter. Speaker B sounded like a full-range presentation; subjectively it was satisfying on its own terms. I had to check to make sure I hadn't somehow left the midrange or tweeter connected. I hadn't.

G'morning Tom
Either my coffee hasn't kicked in or your speaker numbering is flipped from one paragraph to the next. Regardless, it sounds like you heard a *massive* improvement "simply" by moving to an external crossover.

Oy! I am supposed to be done with my mods!!!LOL
FWIW, one of my all-time top 4-5 speakers is the Avalon Ascent, possibly the only external XO speaker I've heard.

Ah, Bose! *Now* we know the rest of the story.

The CS2 2 is dead. Long live the CS2.2!

@andy2 lots of upgrade info this this thread also. In particular, look for posts by Tom Thiel starting about March 2018. Quite a lot to read and there probably isn’t any one post with the latest info but worth your time if you’re serious about an upgrade. Tom still hopes to offer kits but timeline is unknown (he originally hoped to have 2.4 kits by the end of the year - the best laid plans . . .). 

Thanks for sharing the summary of the upgrade choices, Tom.

@rojacob if you successfully upgraded the coax feed caps to SE then I can’t think why you could not also build an entire new board. You must have taken the coax board out to access the solder joint underneath, right. So, you can solder and have experience working in that space. 

Building a whole new board is not any more technical than that, just a much bigger project! And I imagine Rob Gillum could also assemble the new boards for a price but this would still require the user to replace the extant XOs. But we’re getting ahead of ourselves. For the impatient adventuresome, you might proceed on your own with the clues Tom has shared. Otherwise, i suggest waiting for the kits. Some of the caps and coils are custom values unavailable from retailers such as partconnexion and sonic craft. For example, good luck finding a good quality foil cap in 14 uF. You can get the correct value by running caps in parallel but this adds to the size and expense plus could have negative sonic consequences.

@rojacob does your 2.4 have a printed circuit board or point to point connections on masonite (or similar)? The pcb version must be soldered from the bottom. Hard to imagine that operation without removing the boards from the cabinet. 

@rojacob I intend to take pics when I build the new boards and I have several from when I replaced the resistors. Not sure where I might post these but perhaps Tom will share them with the kits - unless I eff it up! LOL

Regarding amplification, either I don’t listen as loudly as others or your Thiel models are especially difficult loads. When I had CS1.6s, i drove them with an Ayre AX-7; 60 W into 8 ohms, doubling into 4 ohms. That amp had plenty of balls to drive the 1.6 to any SPL I cared for. Sounded terrific other than a distortion in the upper midrange or low treble with certain recordings of female vocalists. Pretty sure this was from the Thiels and not the Ayre. My room is 18x19 with a vaulted ceiling and two large openings on the rear wall.

I’ve now moved up the chain to CS2.4SE driven by an Ayre AX-5: 125 W into 8 ohms, doubling into 4. Again, this “modest” amp has plenty of guts to drive the Thiels as loud as I care for without any sense of clipping or distress. YMMV.

That said, the impedance curve for the 5 certainly looks like a challenging load and I would pair that with something capable of delivering more current.

@andy2 I assume you mean non Thiels with a concentric driver? I’ve heard the TAD Ref 1; it has a concentric driver with diaphragms of an exotic material that I don’t recall. One of the very best speakers I’ve heard. Just stunning, but you’d hope so at that price!

My very short list of all time favorite speakers includes both time-phase correct and not. I don’t know if that part matters to my ears a ton but I will say that my favorite speakers at real world price points are Thiels and Vandersteens. One important feature, IMO, is that both of these designers use light and rigid materials in the midrange and with diaphragms <5”. This is super important to avoid distortion in the critical midband. It amazes me that some really high dollar speakers use 7” drivers for the midrange. No thanks!

Yes, front baffle of the CS2.4 is 3” MDF. Don’t know about the 2.7, but imagine it is the same. Was that model ever reviewed? 

@prof thanks for those links. No wonder I never saw those reviews. I haven’t read TAS in years, their credibility is near zero, IMO. And hometheaterhifi is not one I look for.

I didn’t read all of those links but they do say that the sides are plywood (that veneer job must be interesting) and that the baffle is 3” but without specifying the material. Hard to imagine that thickness would be any other than MDF.

Tom has an idea to identify cabinet surfaces with resonance issues but I was unsuccessful at helping him with my setup.

Judging from the Stereophile review and measurements (never heard on for myself), the New Thiel TT1 seems like a competent design. But why buy one? If I want a competent (but still sourced from the Far East) speaker using "conventional" engineering I would just go with something like a Revel (better yet, the Canadian made Bryston). It is not surprising to me that the New Thiels were duds at the dealers.

On an alternate timeline, New Thiel continues to make CS1.7, 2.7 and 3.7, perhaps increasing the parts quality in the XOs much like Tom Thiel is proposing for the legacy Thiels. But even this would eventually need an engineer to keep advancing the product line . . . while staying true to Jim Thiel’s basic design principles.

That said, we Thiel owners are fortunate to have Rob Gillum available with service and parts, as well as a potential upgrade path via Tom Thiel’s mods.

@holco Please note that neither Tom or myself have conducted our own resistor listening comparisons. The Mundorf was on the short list but the Mills rose to the top of the list based on engineering, subjective opinions, and price. If cost were not a factor, I would try Path Audio re$i$tor$. The Mills are a really good and cost effective upgrade over the OEM sandcast resistors. Is it possible the Mundorfs sound better still? Could be but I am very comfortable with the choice of Mills.

There are endless combinations of parts that could be applied in a crossover upgrade and even a full time designer could not have time to listen to them all. Tom has given very careful consideration to the possibilities based on his own extensive knowledge as well as opinions of others with broad experience. Tom only has time for a subset of sonic comparisons. I will compare the sound with and without Multicap bypasses on the coax feed caps. I might also compare foil and wire coils. But I trust that Tom has made good choices, just as I trusted those of Jim Thiel.

@andy2 the initial build will replace coax board wire coils with foil. Woofer board coils will stay wire for now. Tom will make further consideration as he gains knowledge with his 2.2 and 3.6.