Thiel Owners

@tomthiel, I wish I could share your faith in Thiel users getting amplification right. It seems that many seem to choose to ignore the basics. It’s not entirely their fault. I’ve seen different dealers offering what to me where incredulous demonstrations. Such as powering CS 3.6’s with 20  Watt intergrateds or CS 5’s with 50 Watt amps all the while resorting to their cheezy salesmanship gimmicks of grinning with crossed arms, nodding their heads up and down, tapping their foot,...all at barely audible listening levels. They were none too happy when I increased the volume to much, much less than typical listening levels. They would then lower the volume some and say that at these volumes the amps were sufficient, all the while the sound was of crunching distortion.
 Your points about radiation patterns and room placement were spot on. And let me clarify that even with DSP it would be preferable to work with a speaker that already was designed for a specific predictable placement rather than against it. Even if we’re not quite there yet, I firmly believe that DSP is the future. Though we may have to abandon previous notions to embrace the advantages of a new paradigm.
 The shared insights as to why the Thiel’s tend have low impedances was most interesting. In that there are still a few amplifiers to choose from that are up to the task justifies the gains in cohesion, ease of placement, and especially reducing lobbing effects.  I am continually impressed by the latest flat co-axils.
 Your comments about free standing cross-overs was most interesting. I seem to recall reading an article where Richard Vandersteen had the same “AhHa” moment with similar circumstances of free standing first order cross-overs. I never gave it much thought before. Perhaps vibrations, EMI, RFI, all, some combination, or none of the above? I’d be most interested in following your research on the matter. I’m still curious about your research on baffle reflections as well. Thanks so much for maintaining the research progress of our favored Thiel’s.
 

Unsound -
As you say, sufficient power is an absolute requirement. I may be naive, but I'm thinking that with good used equipment available at bargain prices, education would be fruitful because many folks could actually afford good to great solutions.
In addition to EMI and RFI from the interactions between the crossovers and the drivers, there is the proximity to metal driver frames and pressure fluxuations. A big deal is that cabinet vibrations necessitate every component being glued down to avoid microphonic and fatigue vibration. Plus the cabinet is a closed cavity, so heat generated by the crossover losses as well as the driver motors, wh heats up everything, changing the component values and circuit functions. It's not subtle. By outboarding I can dump crossover heat at the crossover and driver heat via heat sinks and thermal malpractice and compression are greatly reduced. each component can be mounted for maximum cooling.

The baffle stuff is quite intriguing - newly developed plate resonators to quiet and organize the launch waves. Coupling of driver motion to proper air waves is less than trivial as well is the chaos of early diffraction. Thiel paid lots of attention to that, but more attention is fruitful.

Here's an aside. I can play a woofer in a cabinet adjacent to its mate with the mid-tweeter. Same feed signal. Taking the woofer-induced vibrations out of the (upper) cabinet cleans up the high end considerably. Imagine that. I thought the CS2.2 cabinet was quite quiet, and it is by comparative standards. But better is better. I can remove the cabinet top and bottom to doctor the cabinet walls, newly accessible from taking the crossover outboard. Two versions under development. Underslung Crossover places the 3D network in a vibration-insulated and ventilated chamber under the cabinet while the Outboard Crossover version puts it in a free-standing enclosure about 3' behind and connected by an umbilical to the drivers.

To your point about the flat coaxes. Jim wanted coaxes from the very beginning for their solutions to placement and lobing problems. It took till the SCS in the late 80s to execute the coax and gradually get the outer cone more and more shallow to minimize the squak-effect. The flat-wave solves so many issues.

@tomthiel, Yes, you would think with quality that originally went into them, that some of the amplifiers on the used market would be especially appreciated at their now discounted prices.  Too many are caught up in marketing of the “latest and greatest” gear getting all the most recent attention. While there has been some improvement in some specific parts, these parts are not necessarily exponentially better, and many can be retrofitted to older gear. Some of the newer amps don’t actually perform as well as the older stuff with the speakers at hand. Interestingly, some of the more recent amps are actually based on even older circuit designs. Which in itself might or might not be a good thing. The perception of the suitability is sometimes different than the reality. The physics hasn’t changed. Not being mindful of the criterion used to make the lists, or how the maker of the lists keeps a revenue stream going; it’s as though if it’s not currently on a Class A rating list it can’t be any good.
I hope all your super good work(!) comes to fruition for us Thiel lovers soon!

I want update my journey with the Thiel CS3.7 now that some changes were made.

1) A speaker repair tech came to my house today and re-soldered the crossover wires to the tweeter and midrange of my right speaker. They were wired out-of-phase during a prior DIY OEM COAX replacement. The speaker seller has volunteered to pay for todays repair.

2) I discovered a damaged screw thread on the left speaker frame. Rob Gillum pointed me to a toolkit to repair that. It is being shipped to me now ($44). The original speaker dealer seems to have gone torque crazy with the driver screws.

3) I will sandpaper and lacquer the speaker because this speaker is never leaving. Rob Gillum gave me instructions on best approaches for that.

4) I ordered the outriggers from Rob G. for the day that my 4 year old son decides to climb the speaker.

After #1 was done today the speaker sound just opened up. The harshness is gone and the soundstage is huge the imaging is better. Just like I remembered 12 years ago at the store demo. I think it actually sounds better today on my all Benchmark stack than the all Classe gear of the demo.

Getting to that Benchmark stack. I have been disparaging the AHB2 Stereo amp with the CS3.7. Saying it sounds lean and not dynamic. I was thinking in my small room 194 watts at 4 Ohms should have worked. The amp also goes down to 2 Ohms but I do not remember the numbers for that. However, the sound was not that good wherever I positioned the speakers. I think I said on a scale of 100 it felt like a 75, even less on dynamic music. Today, after the out-of-phase fix the sound is powerful, dynamic and glorious. I would say a 95 out of 100 now. The room is still there so not a 100.

I am kind of curious still about the CODA #8 amp with the CS3.7 but I do know that the AHB2 will never leave this system. I caught a lucky break by not selling it a few days ago to fund the purchase of the #8.

So in a small room, see my Virtual Systems, the Thiel CS3.7 + an all Benchmark stack (with a single AHB stereo amp) sounds amazing.

I will explore the DRC implementation tomorrow now that the drivers are working right.

BTW - I was just thinking that reason that the it was easy for me to hear the out-of-phase problem was because of the revealing nature of the Benchmark gear.

I also now feel that for my room the Luxman m900u and the CODA #16 would also be viable alternative amps. I do not need the massive amounts of power at 2 Ohms for this room.

@jafant I ordered the Mofi version of Santana’s Caravanserai. My current SME version now sounds better on the CS3.7 than on my Meze Empy headphones. It sounded better on the headphones prior to my speaker repair today.

Looking forward to the MoFi version since you say it is the better version.