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!
The 3.5 EQ will stay, since it is a vital part of that product. The sealed bass drops off about 100 Hz at 12dB / octave. That would blend very well with a subwoofer, but by itself is pretty bass-shy. The two position EQ extends to 40Hz and 20Hz, which is extraordinary - albeit amplitude must be reduced to avoid bottoming the woofer, which is why the EQ's bass was abandoned as digital sound-tracks came into vogue. In due time I will be addressing the sound quality of the EQ unit. It's a good circuit but could benefit from better signal path components. There is also interest in a fully balanced pair.
I have settled on an order of go. In order to hone my chops, develop hardware and software solutions and walk before running, I have decided to address oldest products first. Their end-of-life is more immenent, and there is generally greater room for improvement than in newer, more advanced Thiel products. So, I am beginning with my prototype 02s. One version will use existing drivers and another will replace the drivers, which are obsolete. There will be cabinet and component upgrades. The 02 pre-dated any knowledge or availability of high purity wire or film capacitors. I will replace all XO components with appropriate best-of-form, keeping the 2nd order XO topology and port, but everything else being fair game. This project should come easier and faster than the more complex models. I hope some folks here will like this - I know I will like doing it. 1976 revisited.
Next will be the CS3/3.5. Since all the drivers need updating, it is likely that we can refit both CS3 (1983) and CS3.5 (1988) with identical drivers and very similar XOs. I'll skip the CS5 and take on the CS2.2 (1991) next. Those products should provide a good foundation for further models.
There has been suggestions to call these updated models -R for Reissue or Resurrection, or -AL for AfterLife, or who knows what.
Good to see you today. Nice score on the mint pair of CS 2.2 loudspeakers. Thank You for proposed updates to this model as well as the C3 and 3.5 models. No doubt that there is a market for these updates/upgrades among proud owners. Keep up the outstanding work!
Guys - I am approaching the 02 first for lots of reasons including access to alpha-testing a new port technology in addition to the MO being developed for the other products. Can this forum provide an idea of how many pairs are out there? How many pairs of 02s are there among you and those you know?
02 owner here, as you know. I still have the 02s in my system now (the poor 2.7s are standing beside them with folded arms and a "what are you thinking?!!!!" expression on their drivers). Still loving them.
Did you receive those 02s yet? And if so what do you think of them?
Prof - the 02s have not yet arrived due to complications at their Virginia storage location. Should be here soon. A proper resurrection must include new drivers, since the originals are no longer made. I am exploring. I'll stay with fiber diaphragms since part of optimum second order functioning includes diaphragm breakup modes with inverted polarity hand-off.
Wow, as an owner of two pairs of 3.5's and one pair of 2 2's, I am licking my chops to see what you come up with. I love both models, but agree they could use updating. I can just relax and listen for now .... not a bad mode to be in! :-)
I wonder if Tom or someone else could comment on this. I found an image of a supposedly CS6 xover for the midrange. Based on the image, it seems the xover employs an all-pass filter for the midrange. In my experience, the all-pass dues to the amount of components, does take away some of the transparency. And seeing from the image, it does not seem like any bypass cap was used so it may help. I was just wondering if all-pass filter was widely used at Thiel for the purpose of time-phase aligning?
I've read a review of the CS6 from Stereophile and the author did comment of the slight reticence of the midrange that may be related to the all-pass nework. See the excerpt below:
So far I've been digging deep into my box of superlatives. Did the CS6 have an Achilles' heel? It did, in that the midrange didn't offer quite the same degree of ultimate clarity or cleanness that so distinguished the bass or treble octaves. There was a feeling of reticence in this region, described by one visitor as a "hooded" quality, that I couldn't eliminate no matter how much I fooled around with placement. Tilting back the speaker by placing Black Diamond Racing cones under just the front did help, however, as a distinct change in timbre could be heard on the sit-down/stand-up test. But for me, at least, this was a minor problem, offset by the many things the Thiel did right.
As a 3.5 owner I'm very excited to read that Tom will be giving the design some TLC. I already use dual subs with mine, sans my EQ box, and find this allows me to fine tune the speakers to my music room. I think this configuration also gives the relatively fragile midrange drivers an easier time. I'll be watching developments with great interest.
Cat - for the record, I agree that a subwoofer solves many problems. And for the record, Jim also agreed, but we weren't ready to address subwoofers at that time in our development and, especially then, subwoofers were routinely badly implemented. My reason to keep it in the R series is a tribute to history, the integrated solution at the time. Note that sans EQ, the sealed bass rollout of 12dB/octave will behave very well with bass management systems.
Andy - I haven't seen the CS6 XO, but can comment generally. Jim employed all pass filters - Zobels and custom - to counter rising impedance with rising frequency as well as shaping networks to trim each driver toward its theoretical optimum response. Over the years, including the first-tier New Thiel period, reviewers, dealers and other knowledgeable folks would counsel Jim to scrap all that stuff. He was steadfast in his desire to create an ideal resistive load. The "amp problem" would be far worse if Thiel's low impedance x first order were to introduce the additional burdens of reactivity.
Our present 'R' approach (Beetle's 2.4s and my PP & 1.6 experiments) is to upgrade all those components. The degree of audibility of parallel / shunt / non-series feed components is far greater than generally believed. Improvement can be heard via a higher voltage cap of the same construction - even in circuits that "don't matter much".
I would appreciate seeing the XO picture and especially comments from you and our other DIYs. 'The veil' is quite delicate and expensive to address.
Hi Tom, Here is the link to the xover picture. Based on the website, it is supposed to be a CS6 xover picture. I was afraid of revealing possible intellectual property, but I guess since the website is public, it should not be an issue, at least from my stand point.
That photo is probably an early or prototype version which goes to shows and seminars. Typically it will morph through a year or more to match the actual settled particulars of its driver complement. At first glance, coils are 4-9s, best of form. Significant improvement could be made via cap and resistor upgrades from AXON, electrolytic and sandcasts. Beetle might have an opinion. Cheers. TT
The degree of audibility of parallel / shunt / non-series feed
components is far greater than generally believed. Improvement can be
heard via a higher voltage cap of the same construction - even in
circuits that "don't matter much".
Does this mean you corroborated my listening tests?
At first glance, coils are 4-9s, best of form. Significant improvement could be made via cap and resistor upgrades from AXON, electrolytic and sandcasts. Beetle might have an opinion.
The coils are certainly of higher quality construction than those on my FST-sourced 2.4 boards. And the yellow caps appear to be the high quality polystyrene 1 uF that Thiel commonly used. I see one bank of electrolytic caps. Those are probably shunts but I found shunt cap upgrades to be audible. ELs not only drift with age but they are generally lower SQ than film caps. The other caps are probably metalized film type but it’s hard to tell for sure. I see at least one cap with the Solen logo. The resistors appear to be the sandcast wirewounds.
I am confident that improved SQ can be had by upgrading the parts quality. If that was my CS6, I would replace all resistors with Mills MRA-12s. I would want to see a schematic before commenting about specific caps but I can say that better caps substantially contribute to improved transparency and resolution. Whether this would fully mitigate JA’s one criticism of the CS6 I have no idea, but it would certainly get you at least part way there. Andy2, curious to know what you see on that board. How did you surmise an all-pass filter? An all-pass filter suppresses no frequencies, right? Seems like such a "filter" would invariably allow the driver to excite its resonant modes.
One thing I learned form Tom - and that greatly surprised me - was that Thiel used the same level of parts quality on all models from the 1.X to 7.X. I confidently predict that better parts quality will improve SQ for all models. That said, DIYers should know that it’s not necessarily as simple as replacing OEM parts for higher quality ones with "identical" values. In particular, changes n DC resistance can modify the voicing.
Andy2, curious to know what you see on that board. How did you surmise an all-pass filter? An all-pass filter suppresses no frequencies, right? Seems like such a "filter" would invariably allow the driver to excite its resonant modes.
It's partly based on an opinion of someone who is fairly experienced in xover design. Also, based on my experience, it seems to me the only way to align the mid to the tweeter phase is to use an all-pass filter otherwise you have to invert the polarity (but I could be wrong).
I have tried the all-pass filter in my own xover design and it takes away the transient speed and ultimately reduce the transparency.
As always, Thank You for the opinion regarding Tom's query about XO networks. You guys definitely have your finger(s) on the pulse of this matter. Happy Listening!
I interpreted "all pass" as any filter that is not causing a rolloff. As I used the term, there are multiple all pass elements in all of Jim's crossovers. They include various shaping and resonant circuits which are directly opposed to specific resonances in drivers such that the circuit cancels the amplitude, phase and transient problems of the driver resonance. It actually fixes the driver misbehavior. The fixed driver is therefore prepped to roll in or out at its prescribed slope - high or low pass filter.
These shaping circuits always result in better measurements than the uncorrected driver in all domains. The down sides include cost and whatever electronic veil comes with the extra circuitry. A good listener can hear the effects of the components. Thiel's budgets necessitated mid-level components with mid level artifacts, with the exception of coils. We splurged for 4-9s wire in well made coils. Of course there is room for more improvement there. I am now experimenting with 6-9s foil coils, which are glorious at twice the cost or 4-9s and 6+x the cost of normal production 3-9s ETP copper.
It’s above my pay grade to speculate whether you’re onto something regarding the XO design and JA’s subjective opinion, but I am confident higher parts quality will improve transparency for the CS6. It also seems relevant that Tom has told us Jim T’s CS7.3 was likely to include a mechanical XO for the coax unit albeit perhaps for entirely different reasons.
I guess I was just speculating and mostly was out of curiosity. I have not personally heard the CS6 so it would be hard for me to form any conclusion. Hopefully someone here who had listened to the CS and would offer his or her opinions on the CS6 to see how their opinions are compared to that of JA.
My experience with the CS2.4SE included a “glassy” quality in the midrange that was mitigated by replacing the sandcast resistors with Mills MRAs. And the Clarity CSAs (plus better coils) removed veils that I didn’t realize were there (sorry not sorry for the cliche). So, it’s easy to imagine better parts would improve, if not cure, the “reticence” that JA heard.
The CS6 is an interesting model that I considered before settling on the 2.4s. Not as big as the massive 7.2 but still with good bass extension and sensitivity on par with the 2.4. That said, Tom Thiel’s comments about the 2.4 coax driver mass leave me wondering if this is the sweetspot (even including the 3.7) for my priorites of resolution and transparency.
I think it not improper to point out that JA seems to hear what his measurements tell him. At 50" there is a midrange suck-out and some spikes. Notice that he wonders in print if that is what he is hearing. However, those ARE measurement artifacts; they are caused by too-close microphone distance, and disappear at about 8'. Notice that they don't show up in the room-averaged measurements. Nonetheless, he treats them as real.
What we are learning from Beetle's 2.4s and my budding experiments matches what we knew from the beginning - passive parts quality is audible. So I believe the "reticence" is more likely that parts veil rather than the false frequency response artifacts.
I'm a longtime Thiel owner and I've got some CS3 questions that I would really appreciate some help with. Last week, I
couldn’t stand it any longer so I got my Thiel CS3s out of storage
and set them up for the first time in my small (11’ x 16’ x 10’)
acoustically treated listening room. These speakers are over 25
years old, have been well cared for, but haven’t been used for the
last 10 years. I’ve been using Kef LS50s in this room for the last
2 years. My electronics consist of a PS Audio PWD II DAC with
bridge, Dodd battery powered tube preamp, and Dodd 120 tube mono
blocks or ASL DT200 tube mono blocks. My music server is running
JRiver Media Center software.
I’ve owned Thiel
CS3s, CS3.5s, and CS3.6s. I sold the CS3.5s many years ago to
upgrade to the 3.6s. I recently begrudgingly sold the 3.6s because I
felt that my new room was simply too small to accommodate them. My
old music room was 18’ x 14’ x 8’.
Back to the CS3s.
Using the Dodd 120 monos, the CS3s sound really good in my small
acoustically treated room. The first difference that jumped out at
me was the bass, which is fuller, deeper, and more articulate than
the LS50s, without using the CS3 bass equalizer. Even though I was
happy with the bass I was getting with the LS50s, the CS3s outperform
them handily. However, this post wasn’t meant to be a comparison
of the LS50s and the CS3s. The reason for this post has to do with a
potential CS3 driver problem.
I noticed that on
the sound stage, Norah Jones’ voice on the “Don’t know why”
track from the “Come Away with Me” CD was shifted to the left of
center about 10 degrees. I swapped the speakers and the problem
follows the speaker. I also noticed that the difference in output
levels increases as the musical content increases in frequency.
There’s a bigger shift on the “Game of Clocks” track from the
“Smoke and Mirrors Vanish” CD. BTW, this track sounds great on
the Thiels.
My questions to the
Thiel faithful are as follows:
1. Would replacing
the 25+ plus year old capacitors in the crossovers help?
2. Could this be
tweeter failure due to age? I already know you can’t find CS3 replacement tweeters.
3. Any other ideas?
I would love to make these my main speakers if I could solve this
problem. Otherwise, I might look for another used pair because I can't believe how good these sound in my small room.
utrak Welcome! Good to see you here. Sit tight until one of our 3.5/3.6 experts chime in to address your query. Or, if you would like to gain a head start, feel free to reach out and touch Mr. Rob Gillum with Coherent Source Service (859.544.9790) for a consultation. I look forward in reading more about your musical tastes and system. Happy Listening!
This
30 year old Thiel CS3.0 vs LS50 is an experiment for me to try to
understand how good the older Thiels are compared to newer highly
regarded designs like the LS50. I was also trying to determine what
I could get away with in my smaller room with respect to bass. I
don’t want to jump the gun because I haven’t spent enough time
comparing the two but let’s just say that I’m shocked by how good
the 30 year old Thiels are. There’s a good chance I’ll look for
another set of used Thiels if I can’t fix the CS3.0s. BTW, the
CS3s sound really good with tubes and so did the 3.6s.
Take a close look at your mid-range drivers. Seeing any cracks near the surround edge? The replacement mid-range driver currently under testing for the 3.5 may also work for the 3.0
utrak My pleasure. I would think that a 30-year old pair of loudspeakers is going to require some kind of repair/servicing? If possible, closely inspect the cross-over network and drivers. Keep us posted with any findings. Happy Listening!
Utrak - I can offer a broad-brush intention: more than a dream, less than a plan. Rob of Coherent Source Service and I are working on upgrades for various classic Thiel models. The CS3.5 is now on the list, and the CS3 is likely to come along as a hybrid solution. Those designs are similar to each other and all drivers of both models are obsolete. We are looking for replacement drivers to work in both models with appropriate XO tweaks.
To your situation, cap failure is not likely. Thiel used long-life caps and we know of no age-related cap failures - not yet, probably soon. But, drift is likely. Heat-related (over-driving) cap failures are known - you can see the burned caps and replace them.
I suggest you contact Rob at CSS to work out a strategy, since our Classic Upgrades are not yet real, and there are bridges to cross before they come to market.
holco Good to see you this Spring day. Hope that you are well and enjoying the music. Thank You for the link to your gear- beautiful musical juice! Happy Listening!
Thanks for the feedback everybody. I really do appreciate it. I think that I’ll attempt to further isolate the problem by swapping the tweeters first and then the midrange drivers if the problem doesn’t move with the tweeters. I’ll share my results with everybody. Tomthiel’s response is encouraging. I actually think that I stumbled onto something rather unique with respect to the CS3s and my small acoustically treated room. I was actually able to tame the bass by not using the bass equalizer and adding another set of 4’ x 2’ absorption panels (1 on each side of the room) between the corner trap and the first sidewall absorption panel. After doing that, I was blown away. It’s sad but at least I got to re-realize how special Thiel speakers really are. To make matters worse, newer Thiel models don’t have a bass equalizer that I can remove and the impedance curve drops to 3 ohms on some of them, which might present additional problems for my tube amps. I believe that the CS3s are 88dB efficient and the impedance only drops to 4 ohms. Good luck tomthiel. I know that Thiel owners of the world are rooting for you.
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