Thiel Owners

Yikes!  That post about Thiel being "toast."

How does that comport with Jafant's recent contact with Rob suggesting parts will be available?

I interpreted that as he does all the work in his shop - you have to ship the speaker to him. But I don’t know why you couldn’t instead remove the crossover yourself and send only that to him. Maybe it depends on how comfortable you are removing and re-installing the crossover. Also, I imagine he would want to be sure his mods work! In my case, I was thinking about buying speakers that needed to be shipped to me anyhow, so only 1 extra ride in the cargo truck.

If you’re serious, I suggest asking him directly including how many he’s done and ask his opinion of how the mods improve the SQ.

OTOH, if you comfortable removing and installing the crossover you're probably also comfortable upgrading the capacitors (and other parts) yourself. A good place to start might be the latest top-shelf Clarity Caps.

Beetlemania,

Does
" Yes this will be done at my lab and fully tested on the analyzer before shipping "
mean that you have to ship the speakers to him for this to be installed? It is unclear how this answers your question:
" Is this done in your shop or do I install the new boards myself? "

just saw this and wanted to share.  not surprising.

https://www.strata-gee.com/thiel-toast/

FWIW, eBay lists a "crossover upgrade service" for Thiels -- I have not explored this though.

Yes, I saw this and exchanged a couple of e-mails with him. Me:

I am considering buying Thiel CS2.4s and am curious about your crossover upgrade. What does this entail? Is it similar or better than the CS2.4SE crossover with Clarity Cap capacitors? Do you need the speaker or would I install the new crossover myself? If the former, can you upgrade the wiring at the same time? Also, there is a pair of 2.4s on ebay right now but they lack the cable nut. Do you have any ideas for replacement of those (I have Cardas cables with the spade connection)?

Him:

You get clarity cap with vishey bypass in the tweeter section. Electrolytic capacitors will be replaced with new ones as they go bad after 20-30 years, also where possible electrolytics will be replaced with film caps or bypassed to improve performance. Inductors will be upgraded as needed with larger awg wire type and resistors in the tweeter section direct path will be replaced with film resistors or mundorf type.

Upgrade cost is $210 each.

The terminal posts on the back can be replaced. Not sure if I can find just the nuts.

Me:

So, $420 for the pair. Is this done in your shop or do I install the new boards myself?

If the terminal posts are replaced, can the new terminals be the Cardas clamps? Can it be re-configured for bi-wiring?

Him:

Yes this will be done at my lab and fully tested on the analyzer before shipping.

Yes you can go bi-wire, but fancy terminal posts can get quite expensive and using 4 of them will increase the price. If you have a specific terminal post you would like to use, let me know, send me the link.

Once we decide on all the detail we can figure out a final price.

Here is my website to understand more of what I do. I normally design as a consultant for some brand speakers, but work has been slow and am doing this ebay thing for the time being.

Nedlab.com

Seems promising to me. Who wants to go first? Might also be worth asking Rob Gillium if he offers upgrades for the crossovers. What we really need is a geek who took the time to experiment and listen with a bunch of parts combinations (it sounds like Jim Thiel did this when he selected the Clarity Caps). This is why, IMO, Wilson speakers perform as well as they do. The basic technology and drivers are, um, basic. But Dave Wilson, apparently, is a careful listener and finely tweaked his cabinets, crossovers and wiring accordingly. The final products is not without flaws but far better than otherwise.

@jafant

There is an improvement between the CS 2.4 / CS 2.4SE, believe me, I spent many hours of listening to ensure that nothing was remissed.

So, you directly compared the two models? Neither of the webzine reviewers were able to make that comparison. I heard the original CS2.4 probably 12 years so I really don't have a reliable reference for how the SE version is better. All I know is that the SE version is incredible! Gotta give credit to my source and amp, but the Thiels are reproducing their signal superbly well.

Beetlemania,

Your remark "I'll venture to guess that a tricked-out CS2.4 would retail for $10-15K but compete sonically with other designs up to $40K. A tricked-out CS3.7 might retail in low $20Ks but be considered as among the best speakers available" got me to thinking. I'd certainly be interested in something like that for my 3.7s, not that I'm unhappy with them in their current incarnation! It certainly would be an opportunity for an enterprising individual to offer that kind of mod service. FWIW, eBay lists a "crossover upgrade service" for Thiels -- I have not explored this though.

 Any savvy technicians out there with knowledge of the Thiel crossovers?

Though I would have been interested in a longer conversation with Jim, to draw him out on the subject and see how he may nuance things.

Well, I think it's telling that he called the Clarity Caps "boutique" capacitors. That sounds quite condescending to me. My supposition is that he was pretty firmly in the "objectivist camp" (measurements tell you everything you need to know) for most of his career and only reluctantly admitted, towards the end of his life, that measurements don't tell you everything.

There is no doubt that his designs measure superbly well (except as measured by Stereophile - JA's "quasi-anechoic" method limits the mic distance to a mere 50"). Soundstage's measurements of the CS2.4, for example, are among the best they have examined in terms of flat frequency response and low distortion. And I consider his drivers to be among the best ever made - near-pistonic behavior albeit handicapped by the slow roll-off of the first order filters. But that quote to Jeff Fritz, shortly before Thiel's passing, clearly indicates that he recognized that not all sonic improvements can be quantified by machines.

beetlemania,

No that doesn't sound insincere.  I think Jim was a pretty straight-shooter, so that suggests he believes he heard the difference.  Though I would have been interested in a longer conversation with Jim, to draw him out on the subject and see how he may nuance things.

Thanks! for sharing- prof and beetlemania

I tend to agree with Jim Thiel and Bill Conrad, respectively.
There is an improvement between the CS 2.4 / CS 2.4SE, believe me, I spent many hours of listening to ensure that nothing was remissed.

Regarding Conrad Johnson, if one is considering a model of pre or power amp, and there is a "SE" upgraded model available, go for the "SE".
Totally worth those sweet teflon caps and vishay resistors.
Happy Listening!

@prof Do you think Jim Thiel was insincere when he told Jeff Fritz:

The improved resolution is not the kind of thing that shows up well in measurements; the magnitude of the difference between the CS2.4 and the CS2.4SE is more easily heard than discerned from graphs. The new capacitors allow more nuance, air, detail, and decay to be reproduced by the coaxial drive unit. This was especially evident to us when listening to recordings that contained realistic reverberation, as well as recordings where the instruments were not processed heavily.  

?

I'm very glad that Jim Thiel took the path he did in terms of value for money.  I always appreciated the fact that Thiel never went into that ridiculous-price territory we see in many other manufacturers.  A top of the line Thiel competes very well with much more expensive speakers from other companies.

(As for Jim's "change of heart" about measurements, I'm not so quick to interpret it that way. The signature strikes me as perhaps a concession by Thiel that audiophiles really go for boutique parts upgrades, capacitors and the like, so this is a concession to that.  Similar to how some manufacturers continued to include bi-amping posts on their speakers because they knew audiophiles wanted them, even if the manufacturer doesn't share the same belief).

Alternate timeline fantasy . . . What if Kathy Gornik had hired a tweaking engineer ca. 2010. Keep the drivers and cabinets pretty much the same but tweak the crossovers, wiring, and binding posts to the nth degree. Here's @lrsky  in another thread

Back in the day, I used to ask Jim Thiel why he didn't use better caps and air core inductors, resisters, etc, in his crossovers. He would coyly say, 'Because they measure as they do with the components I'm using.'

That was all well and good--but then the next day, I'd be talking to Bill Conrad of cj, and he'd be waxing poetically about the caps they were having made to their specs and how they spent hours deciding which cap goes where and so on. I was confused and frustrated with Jim, one of my icons.

Many years later, I realized that the 'pragmatic' business side of Jim was simply winning the battle for saving the world from bad audio, and keeping THIEL Audio in business. Every, we'll call it 'additional' penny(s) a manufacturer spends on internal parts, is a penny that doesn't come back as profits. So, if a $.58 piece of stuff works, why spend $4.35?

It wasn't until the twilight of Jim's life that he publically changed that position by making the CS2.4SE. As you may know, it offered upgraded parts in the crossovers. When interviewed, Jim said, 'Well, there are some things that can't be measured, but exist in audio.' I'm paraphrasing, but that's the intent of the comments.

I'll venture to guess that a tricked-out CS2.4 would retail for $10-15K but compete sonically with other designs up to $40K. A tricked-out CS3.7 might retail in low $20Ks but be considered as among the best speakers available.

But back to reality . . . best wishes to Rob Gillium!

Right On! beetlemania

those queries would be better served and answered by Mr. Gillum directly.
Like you, I am curious to learn more about his stock and overall speaker repair, rebuilding, refurbishing capabilities.  I am relieved that he is attempting to run a separate entity from Thiel Nashville.

Happy Listening!

In fact, he is working on becoming the owner/operator, solely, of Thiel Customer Service where our legacy products will continue to receive the care.

I figured that was the more realistic scenario, thanks for sharing jafant! Great news, indeed, Seems like a sketchy proposition for Mr. Gillium, though. Will he honor warranty service for products still under warranty? If yes, he can't possibly pay the bills, much less make a profit. Maybe there is enough post-warranty repair service to generate revenue?

Also, what is the remaining stock of drivers? Can he fabricate more? That would be cool if he is in possession of the machinery needed for that! From there, he is only a cabinet maker away from  . . .

Alright Guys-
I reached out and touched Mr. Rob Gillum recently. He is alive and well, more importantly, remaining focused on Thiel customer service in KY.
He is celebrating 30 years w/ Thiel Audio. He is not planning to retire (God willing) any time soon. In fact, he is working on becoming the owner/operator, solely, of Thiel Customer Service where our legacy products will continue to receive the care.  Open for business!

For those interested, send him an email or pay a phone call congratulating
Mr. Gillum on his service with Thiel Audio. 

Happy Listening!

Not a bad idea- stevecham
keep enjoying those CS 2.4 speakers.
Happy Listening!

Good to see you- robinbarbour
hope you are well this new year.
Happy Listening!

Is this a joke, question or a statement?
Nothing on the web about it.

The people who worked at Thiel while Jim was alive understand the design process and what went into classic Thiel products. If only Kathy Gornik bought it back and hired back those same people, perhaps the mantle could be carried forward. In the meantime I will treat my 6s and 2.4s with loving care in the hope that I can make them last for the remainder of my life.
Also, bought an SS2 with dedicated crossover for the 6s about 14 years ago. I could never get it to integrate or phase properly despite trying every setting combination under the sun; I eventually sold it because the 6s sounded much better without it.

good news for you guys

Kathy Gornik bought it back for pennies and will resume production of the CS2.4SE and CS3.7?
:)

In progress- beetlemania.
I hope to have good news for you guys very soon. Thank You for the inquiry.

Happy Listening!

@jafant  did you get a chance to inquire about driver availability?

prof-
keep us posted as you massage iso-lation products under your speakers and into your system.
Happy Listening!

@ronkent,

The iso-pucks can be used for any device within their spec limit.
The web site mentions a variety of speakers, from monitors to bass amps under which to put the isopucks, which of course use the same principle as the Gaia footers.

My Thiels are 77 lbs each, 4 iso pucks are rated to 80 lbs, so they should be fine used for the Thiels.

Excellent ronkent-
I want to say that I have read on other audio forums about using Mapleshade platforms under Thiel speakers to very good effect.
Not too many own Mapleshade racks and footers, so it is refreshing, to read about those who do. Sound Anchors and CS 2.4 speakers are a sonic match. I have not read about CS 2.7 owners using Sound Anchors?

Happy Listening!

On my 2.7's, i had been using the outrigger with the spikes that came with them. Replaced them with big brass feet from Mapleshade and that was a nice improvement.

Also, Avalon makes some cones (aluminum? stainless steel?) that I might try down the road. Probably the best result is obtained by using three per speaker but that seems a gravity risk!

you are welcome.  wish we could post pics here.  I like Mapleshade products and my rack is the Samson rack which is pretty awesome and actually a good deal for what you get.   I would also use the platforms under my speakers but to get that size is pretty high $$.  And as i posted earlier,  and i have not put them on audiogon,   i do have a set of the sound anchors that should work for the older 2 series if anyone is interested.

Thanks! for sharing- ronkent
another excellent tweak suggestion for us Thiel lovers. Good to read more positive reviews of Mapleshade products.
Happy Listening!

" BTW...

I tried some Iso Acoustic Iso-Pucks under one of my Thiel 2.7s tonight.

Some here probably know Iso Acoustics products are all the rage these days in terms of speaker stands/isolation and their Gaia series speaker footers seem beloved."

I do not think the iso pucks were ever designed for a floor standing speaker at all.  I think they are really for electronics as was mentioned above.  On my 2.7's,  i had been using the outrigger with the spikes that came with them.  Replaced them with big brass feet from Mapleshade and that was a nice improvement.  Recently I too got a set of the Gaia feet that i screwed into the outriggers.  My girlfriend liked the brass feet better but i liked the more expansive sound with the Gaia. I think either the Gaia or the brass feet are worth looking into depending on your sound preferences. 

Good luck, bcarr38
In your previous post you wrote:

I have a pair of CS 2.3s with upgraded coax speaker which sound great but I am interested in upgrading

Was the upgrade the driver or crossover?

I am *really* happy with the CS2.4SE. It can't reproduce the left-most 2 or 3 keys on a piano but I can't hear any other weakness or shortcoming. I'm very curious to listen to a Vivid Giya or TAD Ref One or Vandy 7 again to discern how those designs are better (of course this will be confounded by changes in electronics and room). To be clear, I'm not imagining the CS2.4 is their equal but surely those speakers are near the horizontal asymptote on the performance/price graph.

have you thought about what might be the weakest link in your system? ie, consider upgrading you source or amp first? IME, these are just as important as the speaker.

Thank you beetlemania.  I will check it out.

I forgot to mention what was probably the key feature in favor of the SI-1 for me. It has fully balanced circuitry, not just balanced inputs and outputs. The only other active crossover I found with this feature is a particular variant in the Marchand line, the XM44-2FBA. Since my pre and power amps both have fully balanced designs, I wasn't keen on inserting a device with unbalanced circuitry between them.

I tried some Iso Acoustic Iso-Pucks under one of my Thiel 2.7s tonight.

I'm not familiar with this product but, as a rule, isolation footers should be used only for electronics and, maybe, cables but never speakers. I'm not surprised you didn't have good results.

I am using small wood blocks under the spikes of my CS2.4s but only because I am protecting the rug they sit on . . . I'm not willing to damage the rug. At some point, I will take the rug out and listen for how much, if at all, the wood blocks are degrading the SQ.

Excellent reporting- prof, ish_mail and beetlemania

very informative information for those wanting to integrate a subwoofer or two into their system. Equally important is the mention of isolation of your speakers via outriggers or some other product in kind.
Much will depend on the room, type of flooring and other sound treatments.
Fun stuff to be sure. Is not this hobby great?

Happy Listening!

BTW...

I tried some Iso Acoustic Iso-Pucks under one of my Thiel 2.7s tonight.

Some here probably know Iso Acoustics products are all the rage these days in terms of speaker stands/isolation and their Gaia series speaker footers seem beloved.

I'd been meaning to try out the Gaia footers, but ended up first with 4 of the slightly smaller iso-pucks which I'd picked up mostly to test for use in isolating my new turntable.

Using an iPad accelerometer sensor app, I did much of the same tests for the iso pucks as I did for a bunch of other materials, and frankly couldn't find much measurable isolation.  Still, I thought I'd try them under one of my 2.7 speakers.  I'd heard a store demo of the Gaia footers on one speaker, where they switched back and forth between the one with the footer and one without, and thought maybe I'd heard an agreeable change.

But on my Thiels tonight, it turned out I wasn't so happy with the results.
First, the L speaker (that I put the iso pucks under) did become a bit more lush and mellow, less hash to the sound.  That in of itself is nice.
Though that could also be due simply to the 1 1/2" rise in height from the footers, changing the speaker interaction in the room, putting my ears just a bit more below the tweeters for a more midrange sound.  Hard to tell.

Beyond that, the midbass on down actually lost tightness and snap, became a bit resonant sounding and slightly more muddy.  The feeling of aliveness was reduced.  I listened for quite a while going back and forth between the speakers - an obvious difference - and also listening to both in stereo (only one having the iso pucks).  But as soon as I took out the iso pucks the sound became more taught and clean again in the lower mids/bass, and the upper frequency range returned, the whole sound took on that drive, snappiness and aliveness that I love.

So that's a bit disappointing.  I'd love a tweak like that to work for me.
But it's also in line with when I've tried some other footers on my speakers in the past, even spikes.  I tend to get the same changes and end up preferring the speakers flat on my floor, no spikes.  The design of the speakers just seems dialed in for that height relationship with the floor, in terms of floor bounce or whatever.

I'm not sure now if I'm still going to try the Gaia footers.  I may some time spring for the Townsend Seismic Isolation Bars.   The reason is that I've been very impressed with the measured isolation performance of the four Townsend isolation pods I've received for isolating my turntable.  And the isolation bars employ those pods.  The bars, unlike most footers/spike/isolation systems don't raise the speaker height.  So it would seem more ideal for my purposes.

I may try the 4 Townsend pods I have under one of my Thiels, to see how they work vs the iso pucks.  Though they will raise the Thiels probably even a bit higher than the iso pucks.

@ish_mail ,

Again, superb stuff!  Thanks for the reassurance that going the CR-1 route isn't a total screw up :-)   I'm a total newb with subwoofers.

the outriggers are very sweet and very heavy. I have heard the 2.4, 2.4SE and 2.7 models with and without outriggers. To my ears, there is a slightly improved sound and presentation using the outriggers. I venture to report that the difference is not day vs. night.

I hear a small but worthwhile improvement with the outriggers (plus, they look bitchin' and improve stability). It could be because they better couple the speaker to floor, reducing resonances. Or it could be because they bring the tweeters up a couple of inches. You definitely want your ears no more that tweeter axis, maybe a scotch lower depending on how close you sit, your height and the height of your seat.

Prof wrote:

If using a first order crossover with the sub were about maintaining time/phase coherence, I’m not going to have that anyway. The subs will have some delay, and will be placed behind the speakers, hence time delay. I could ideally get them phase coherent with the Thiels with the phase controls, but they’d still be at least a cycle behind in terms of time coherence (unless I go whole hog and want to digitize the entire signal to allow the mains to be delayed for time coherence with the subs - which I’m not yet willing to do.

Prof is right. Even if he places his subs at the same distance from the listening position as his main speakers, the group delay of his JLA subs means that the best he can achieve is phase, but not time, coherence. This is true for both the Thiel SI-1 and the JL Audio CR-1. I explained how I came to post fake news about the SI-1 on this point in my previous post. Apologies for that.

Prof wrote: And, btw, isn't that what the Thiel subwoofer integrator does? Digitize the entire signal to mains and subs?).

Nope. See p 3 of the SmartSub Owner Information manual, https://www.manualslib.com/manual/328036/Thiel-Smartsub-Ss2.html:

All signal processing [in the SI-1 Integrator] is done with analog circuitry. Digital circuitry is used for user interface, calculation and circuit control functions.

How does the SI-1 accomplish level adjustment and phase alignment, accounting for both SmartSub group delay and variable subwoofer placement, and why do SmartSubs lack a phase control? ... We know from the documentation that the SI-1 includes continuous phase adjustment in its bag of tricks for “Smart” integration. Since Thiel surely knew the group delay of its own SmartSubs, computing the phase adjustment to compensate for group delay at any crossover frequency is simple enough. On the other hand, I suspect that the SmartSub circuitry does not account for variable subwoofer placement. Instead, this issue is probably addressed by the instructions on p 9 of the SmartSub Technical Information manual, http://audio.manualsonline.com/manuals/mfg/thiel_audio_products/sw1_ss2_ss3_ss4.html:

The subwoofer(s) preferably should be approximately the same distance from the main listening area as the main speakers.

To the extent that this instruction is followed, the SI-1’s phase adjustment for SmartSub group delay is sufficient for total phase alignment. The user must enter the main speaker sensitivity into the SI-1, and Thiel knows the SmartSubs’ sensitivity. With this information, automatic level matching is straightforward.

OK, then, how can we implement the “straightforward phase alignment and level adjustments” mentioned in my previous post using the SI-1 with non-Thiel subs or if the subs are not placed at the same distance from the listener as the main speakers? Although in this case phase alignment and level adjustment are no longer smart, they can be implemented simultaneously using Method B, as described toward the bottom of p 4 of the instructions that accompany the SoundDoctor test CD: http://www.soundoctor.com/testcd/Soundoctor_Test_CD_v2-7-2.pdf. In this approach we use the level, polarity and phase controls on the subwoofer, just as we would with a more conventional crossover with voltage-type filters, such as the CR-1. Note, however, that the phase adjustment on non-Thiel subs will be the amount needed beyond the default phase adjustment that the SI-1 computes for SmartSub group delay. Fortunately, we don’t need to know the SmartSub group delay to implement Method B, because I don’t know the value of the SmartSub delay.

My initial attempts at implementing Method B indicate that the group delay for SmartSubs and my JL Audio f112s are surprisingly close (within 5 degrees at 80 Hz). I should do some more careful work to confirm this. If anyone knows the group delay spec for SmartSubs, I’d be very interested to know 

In the end, what did I get with the SI-1? Definitely a good price (thanks for not bidding you guys). Definitely a high-quality crossover with a nice remote. Possibly, improved frequency response with the SI-1’s acoustic type filters.*

BTW, I’m very pleased with the results I’m getting so far. I’m definitely hearing the improvements promised for switching to two subs, for using an active crossover, and for addressing phase alignment.

* I think my use of the DARO (automatic DSP room correction) that comes with the JL Audio Fathom line and the fact that my whole system, including acoustic treatments, is designed to optimize the sound at the sweet spot (vs. throughout the room) undercuts to some extent the Sound Doctor’s argument against worrying about frequency response. Jim Thiel believed the difference between acoustic-type and voltage-type filters matters in the cross-overs within our speakers, so why not also for sub integration? … I have no plans to test this conjecture by installing a more conventional crossover for comparison. So with no evidence to the contrary, I’ll continue to tell myself that the frequency response matters, too, just to keep myself happy.

But, as I said in my previous post, no one using a CR-1 or other crossover should lose any sleep over this IMO.

Thanks, @prof

Jim Thiel's concept for the SmartSub line and the crossovers that go with it was to save the end user from having to get into the weeds learning how to integrate successfully. He also wanted to advance the state-of-the-art for sub integration (e.g., SBIR correction in the SmartSubs and acoustic-type filters in the SI-1). The downside for me in using the SI-1 with the JLA's is that I've had to effectively reverse engineer the SI-1 controls and understand the nonstandard aspects of its acoustic-type filter design. Talk about getting into the weeds! Fortunately, I enjoy this kind of puzzle. If I understand things correctly, the integration is essentially the same as it would be with the CR-1.

You should have it much easier working with the CR-1. There's really no need for you (or anyone else) to follow me through the weeds unless it interests you. Good luck!

@ish_mail

Thanks very much for all that info.

I will have to read it more than once to have any hope of processing your post.

It's timely as next weekend I'm picking up my CR-1 crossover to finally test the JL subs crossed over with my Thiel 2.7s.

(I also have the soundoctor CD and info...and I've just received a Dspeaker Anti-Node that I will try on the subwoofer channel.  But first I'll stick with the CR-1 crossover and see how far I can get integration).

Good to see you again- ish_mail
very informative replies to prof 's queries. I look forward in reading more on your research. Happy Listening!

Here come some long-delayed replies to several points raised by Prof on 12/9 in his response to my original post to this thread. First, a correction:

I wrote on 12/9: 

The [Thiel] SI-1 uses first-order crossovers; the [JL Audio] CR-1 uses 4th-order crossovers.

This is what I was told during my research before bidding on the SI-1, but it’s not true, as seen on p 10 of this document: https://www.manualslib.com/manual/328036/Thiel-Smartsub-Ss2.html. (For more complete information, read the whole Integration section, starting on p 8.)

Thiel argues that standard LP and HP filters can not produce linear frequency response in the net acoustic output, even with some extreme tweaks. See pp 8-9 for examples in which optimal independent selections of standard LP and HP filters combined with optimized level and phase adjustments fail to deliver linear acoustic output. The standard LP and HP filters used in most active crossovers, on the other hand, are designed to deliver matched (mirror-image) voltage profiles, not matched acoustic output. For example, the JL Audio CR-1 uses 4th-order Linkwitz-Reilly filters that guarantee matched voltage profiles.

Thiel’s goal for the SI-1 in crossover mode (augment mode is another story) was to match the total response of the main speakers to the total response produced by a generic sealed sub driven by an ideal (according to Jim Thiel) 4th-order LP filter with Q = 0.5 damping. Evidently, “total response” refers to the net acoustic output determined by the voltage profiles of the HP and LP crossover filters in combination with the distinct acoustic properties of the sub(s) and main speakers. To accomplish this goal, he uses a nonstandard, highly customized HP voltage profile to make the total response of the main speakers match the shape of the target sub response (see Fig. 11 on p 10 in which the red curve shows the customized HP voltage profile for reflex mains that are typical of the Thiel line). Once this is accomplished, “straightforward” phase alignment and level adjustments should complete the integration (this is IMO; it’s not stated explicitly by Thiel).

BTW, the first-order crossovers in Thiel’s main speaker line are designed for first-order acoustic response, not first-order voltage profiles. From Thiel sales literature for the CS3.7: “The Crossover is a true first order *acoustic type* that provides the utmost in spatial and depth imaging performance as well as overall realism. This is the only type of crossover that provides complete accuracy of amplitude, phase, time, and energy, and therefore the only type that does not distort the musical waveform.” The design of first-order voltage crossovers is relatively simple; the design of first-order acoustic type crossovers is significantly more difficult and expensive. Presumably, this is one reason why very few speaker designers undertake phase and time-coherent designs.

I wrote:

Note: The 4th-order crossovers in the JLAs are not compatible with the 1st-order crossovers in Thiel speakers.

Prof’s challenge to this comment is well taken. First, the words “not compatible” are too strong. I thought I changed incompatible to “inconsistent” before posting, but clearly I did not. Better yet, I should have written “inconsistent with Thiel’s emphasis on phase and time coherence in speaker design (through the use of first-order acoustic type crossovers). This is accurate, but one might still infer from my comment that the Thiel SI-1 can deliver phase both and time coherence. I did think this was true at the time of my post, based on the misinformation about the SI-1 using first-order filters and my assumption that Jim Thiel would only bother with first-order filters in pursuit of his signature phase and time coherent designs. However, according to my correction above, it appears the main advantage of the SI-1 is more accurate frequency response relative to active crossovers that use voltage-type matching. Is this distinction important in practice? It’s not clear. Jim Thiel presumably thought so, but Soundoctor makes some good arguments that suggest owners of active crossovers with voltage-type matching shouldn’t lose any sleep over it; see here http://www.soundoctor.com/whitepapers/subs.htm.

This still leaves a few more questions/comments from Prof that I should answer. I’ll address these, as best I can, in another post; this one is already pretty long.

Absolutely! unsound.
 a very important cleaning tip. Luckily my speakers were very well cared for prior to my purchase. They still exihibit a very fine shine. I do not know if the previous owner ever used any kind of cleaning product? I do know that the gentleman reported only using a microfiber cloth to wipe them down once per week.

Happy Listening!

Jafant, I would suggest not spraying Endust (or any other product) directly on the cabinet, but spraying directly on a soft cloth first.

Good to see you- prof
good to read that are digging the CS 2.7 speakers. I knew that you would.
Happy Listening!

beetlemania-
the outriggers are very sweet and very heavy. I have heard the 2.4, 2.4SE and 2.7 models with and without outriggers. To my ears, there is a slightly improved sound and presentation using the outriggers. I venture to report that the difference is not day vs. night.  Thiel owners across other Audio forums like Sound Anchors to good effect. Still another option is using maple wood slabs under these speakers as well.
In all of my auditions the rooms were carpet, from the range of, very thin commercial to full on luxury thick.
Happy Listening!

jon_5912
it would be interesting to learn the number of pairs built for CS 3.7 speakers. Good to read that your dealer/retailer and Thiel customer service took care of you.
Happy Listening!

Good to see you- ronkent
did you fix the driver yourself? I will reach out and touch Mr. Gillum next week and report back his current position w/ customer service.
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Many thanks! unsound
for the cleaning tip. I would use this product very sparingly on any cabinet.
Happy Listening!