Thiel Owners

For the record, I am also a fan of John Atkinson and what he has contributed to our industry. The 'fault' in the presentation of information goes to executive policy, which took its turns under multiple ownerships. Present ownership (Y2K+) deemed it politically incorrect to allow that phase coherence was a legitimate concern. Imagine the advertiser pressure if Stereophile continued to present phase / time as a real engineering benchmark! The arc of the journey began with an editorially open mind with JA collaborating with then-publisher Larry Archibald to explore the role of phase-time in the playback equation, and proceeded toward less respect.

Prof - please feel free if questions remain after consulting my previous Thiel measurement notes. Our measurement capability integrated with critical listening was at the very heart of our product and company development.

Beetle - indeed the 2 meter (80") distance is fairly valid. Ordinary speakers don't care much about distance since their drivers are not producing an integrated wavefront, but rather relying on the ear-brain to sort out the phase information. In the case of Thiel coherence, driver integration focuses into an integrated wavefront at about 8' where the measurements would be smoother and room-fill would be more even. 50" graphs are misleading, but 80" graphs are more than OK, certainly showing Thiel in the top tier. But 3 meter (10') are qualitatively better. We optimized for 8'- 12'.

I guess it's just personally disappointing to see all the effort that went into ruler-flat response being presented as less than its actual in-room / as-heard performance. Note that the coax drivers remove much of the mic-proximity degrade, since the more critical upper XO is fixed within the coax propagation geometry. Only the lower XO varies with distance and ear height. And that lower XO is more forgiving due to longer wavelengths and less directional specificity.

Point of History: In the O3 development in the late 70s, We mocked up a tri-ax with a 12"woofer with a huge diameter voice coil to allow a 4"x 1" upper driver coax in it. It was fantasy at that time; it took decades to develop real drivers moving toward that vision. In the mythical world, given resources, time & market, Jim would have developed a triaxial coincident driver.  In today's world with Jim's wavy diaphragm, focused rare earth magnets and magnesium or carbon membranes, such a driver would be feasible. Youth has its potentials. _

tomthiel
Thank You for continuing to share Thiel's history with the panel.
Hope you are well and gearing up for Christmas.

Happy Listening!

Tom, thanks I'll try to find your older post when I have time.

tomthiel

you guys nailed it when Jim optimized for an 8' - 12' listening distance.
Agreed, the ear-brain does have much musical information to sort out under this type of testing condition(s).  It would appear that team Thiel really had fun in those early days of research and development (R&D).

Happy Listening!