Thiel Owners

Indeed.

Thiel's requirements of passing a square wave / exhibiting a single, proper step response, etc. increase difficulty so much that most practitioners consider it impractical or even a fool's errand. We went for it despite the difficulties. We were young and idealistic, plus we wanted to make a mark and improve the art. Over the years, we invented improvements that managed the inherent problems. 

The biggest problem/ limitation is dynamic range because each driver covers 7 octaves rather than 2 or 3. A driver acting outside its sweet spot has larger excursions, must dissipate more heat, enters break-up, etc. All those must be counter-acted with considerable difficulties. We began inventing new driver technologies withing the first several years.

It is also much harder to get smooth frequency response in a coherent system. Thiel's elaborate crossovers create complimentary circuits to correct driver anomalies that steeper slope filters would make less obvious. Also, we migrated to stiff diaphragms because their mis-behaviors are simpler, more predictable and therefore more manageable with circuitry. Those components introduce their own sonic degrades and add cost. 

We addressed these issues as cost effectively as possible. Our performance per cost was extremely high. As manufacturing director and later consultant to other manufacturers, I know that our output/cost was a multiple of average and our margins were a fraction of average. We tried harder.

Thiel's results were often less than best in some respects, but generally first-rate if one values over-all high performance on all fronts. Our speakers addressed everything quite thoroughly rather than a few things brilliantly. We believe our products supported a more musically authentic experience than conventional approaches.

I can say that Jim / we might not have gone there if we had known how hard it would be. I suspect that hind-sight and insight would have led us to the later-stage insight that we used in home theater products. We could maintain respectable phase coherence and proper time alignment while considerably reducing difficulty  with the fudge of keeping first order slopes for an octave on each side of the crosspoint and then migrating to second order symmetrical slopes beyond that. Out of band excursion and erratic behavior is greatly minimized while keeping the critical advantages of single step response and coincident time arrival. But you can't solve the puzzle until you know enough to solve it.

Most brands didn't and still don't even try what we we did. I'm glad we did.

Thanks for Tom as usual for your insights.

I think the CS5 is an example where time coherent was achieved at the expense of a speaker that sounds a bit reticent.  I've read the Stereophile review that the xover consists of a total of 114 components.  That is just too many in the signal path, and it probably contributes to the "reticent" sounding.

Andy - you’re on it, and the CS5 is the best example of thoroughness competing with directness. There are multiple reasons for that ’reticence’. A big one that Atkinson and Archibald underestimated is amplification. The amps they used were current starved, delivering more anemic sound than best of form. The underlying root cause there is the excessively low impedance. I think Jim could have done better there - for another discussion. But to your point there are lots of components. My count from the schematic is 106 including 16 that are 1uF bypass caps. Note, we developed that 1uF (yellow) bypass with a European aerospace supplier as state of the art Styrene film x tin foil. Note also that Jim was fundamentally an electronic circuit guy. He worked as if the well executed electronic circuit did the job as well as could be done. That is debatable.

Of those 106 components, 32 of them are in the conventional signal path. Not particularly over-excessive for a 5-way design.

42 are in resonance (shaping shunted to common) circuits. Quite a lot.

And 32 are in analog bucket brigade time delay circuits in the  upper and lower midrange. This is a big deal where some history might shine some light.

We had gotten Japanese representation in the mid 80s which opened up the Asian market to us - quite rare for an upstart American company. Those importers pushed us for a ’statement’ product in a time where many such products were coming to market. Our best product was the CS3.5 at $ 2450/pair with EQ @ US retail. They wanted something at 10X that price, and we had 150 pairs pre-sold regardless of price. Jim was very cautious and less than wholly confident at that time that we could deliver high value in that class. In fact he didn’t want to make the leap and Kathy eased him into it over many months time. My (over-ridden) opinion was that this product-under-development had a ’natural’ retail price of $15K, but it was introduced at $9300. The other huge deal was time-line. The market wanted it now, and its natural development cycle was at least a year out. All that is to say there were significant stresses in the cycle, and stresses show in product strains.

Our signature straight-plane x tilted baffle format accommodated up to 3 driver set- backs by adjusting tilt and driver to driver distance. The CS5 had 6 drivers. It wanted a concave curved baffle for properly time-aligned driver to listener ear geometry. We solved the bass by placing the woofer between the two subwoofers (fore and aft the woofer launch plane) for a net single-point launch. The tweeter was time-aligned at the top of the stack. The upper and lower midrange had to be recessed about 5/8” and 1/2” respectively. The direct way to do that is geometrically. That would have required a thicker and more complex baffle, which could have all been accomplished with additional lead time, which the market wouldn’t grant. So Jim provided the electronic answer with analog delay, which he considered more elegant. This baffle fit our signature tilted flat plane. This long tale is to provide background behind how such products come to day.

I always pre-visualized new products as we developed our factory.  A CS5.2 could use a shallow cone upper midrange instead of the 2” dome to solve much of the timing issue, and applying our patent-pending double cones to the midrange drivers would increase basket depth options. The more complex 3D baffle shaping was feasible if Jim and Kathy could be swayed. I wanted to compete in the more expensive arena; whereas Jim and Kathy were not enthusiastic. Home Theater was rearing its head and Jim wanted foremost an arena to invent new products. HT became that arena.

So, Andy, back to your point that more complexity constrains a design. I agree. I also add that working to surpass such constraints is the business of innovation. We worked ahead of the curve, inventing many solutions that gradually became part of the industry playbook. The CS5.2 could have put many of those future innovations, such as motor shunts, rare-earth focusing magnets, formed double cones, etc. to good use. Such a path became reality with coincident / coax upper drivers, reflex bass (which I discouraged in our statement products) and so forth and so on. It’s a long tale of a complex stew with an outcome that the CS5 was never revisited, much to my disappointment.

But, as time went on and lessons were learned, there were never any more time-delay circuits, and metal drivers allowed simpler shaping filters; and the speakers worked toward greater clarity and dynamics – and reticence was reduced.

Here's a good one...

Thiel CS3.5 Loud speaker with bass equalizer & high end cables For Sale - US Audio Mart

roxy54

Good Catch! I hope those 3.5 speakers find the next home.

Happy Listening!