JA - the whole thing was exciting. Beginnings are cleaner and purer and closer to the heart. We were exploring new territory from a first-principles perspective free from the prejudices that formal education or credentials would have imposed. Some form of progress was made every single day through decades of endeavor.
Prof - our measuring scheme was rigorous and thorough. But, being a bootstrap skunkworks, we created everything ourselves. We began with a rented HP dual trace scope and calibrated mic. We built a sandbox in the field - literally, sand - to bury the cabinet face-up to learn the 2pi, non diffracted, infinite baffle response. Later came hoisting the speaker into the walnut tree for free-field response. The mic was hung on a conduit, first 6' out and then a 10' joint - Hey! that's it! Outdoors we could use sine wave sweeps, but indoors the boundary reflections muddied the mix - so Jim designed and built 'the bleeper' an interrupted ⅓ octave stepped pulse automated signal generator: 3 cycles, one to accelerate, one to measure and one decelerate - advance ⅓ octave. The kids grew up 'singing' bleep, bleep. bleep from 20Hz to 20kHz. The breeze settles down after sunset for an hour or so of high quality measurements to analyze later in the night lab session. This scene is Georgetown Road, the country house where it began. The development lab stayed there for a couple of years after production expanded into Nandino Boulevard. At Nandino Jim's first lab there was 20 x 20 x 20'. Cubes are not good, but that corner could be walled off. The adjacent back parking lot was 150' x very long, perhaps 500' to first reflection. Outdoor ground-plane measurements materialized with live reference recording and test playback in the same environment. Our building was 100' x 300' and we built a roof access stairway to that 'infinite plane' with virtually no reflections 360°. Cable snakes dropped to the lab below for data recording. The final lab was pretty nice. Office / lab was 20' x 20' x 8' ceiling with a same-size balcony above, all connected to a soundproof room 17' high under 3' insulation x 20' x 32.5' (golden ratio) long plus the 20' balcony above the office. I would call the room quasi anechoic. We covered the walls and floor reflective points with layered sonic insulation and made a measuring tower 6.5' high (golden ratio) for a low reflection - highly intelligible environment. In other words, we knew exactly what the room was adding to the free-field measurements. Drivers were tested in an infinite baffle (flat wall) to identify diffraction effects in the cabinets. We compared everything to its base state. Time domain (diffraction, delays, internal reflections, etc.) must be engineered as temporal distortions. (Many designers treat those effects in the frequency domain, which is fundamentally incorrect.) We compared the incrementally improved 'bleeper', truncated noise, sine sweeps, etc. to commercial measurement devices and chose to keep Jim's stuff due to cost performance analysis in a small, frugal rapid growth environment. (New Thiel bought a Klippel System, which no one has used and Rob is now incubating.
Of critical importance is that Jim knew intimately the behavior of every aspect of the design and understood how they related to each other and the global perfection he sought. In this lab in the late 80s during the development of the CS5, which used best of form European drivers from Focal and MB, we judged that we could make a better tweeter than we could buy. The development of the CS5 aluminum dome tweeter (eventually also used in the 2.2 and 3.6) was driven by Jim's adoption of Finite Element Analysis. We took a pretty deep bite in cost and learning curve and, on the second try, took on FEI for all further developments. The dramatic reductions (10X+) in distortion due to motor subtleties - the copper shunt rings, pole and top plate shapes, cone geometries, etc. - were all facilitated by FEI. I know of no other company, large or small, that optimized such minute details.
All of these techniques are but half the picture. Every single exploration was co-developed by ear. Jim, Kathy and I each brought value to that equation and eventually we added a naive listener component for additional input. (I think I've talked about that.)
Technical "improvements" were always vetted by listening, and often failed if they didn't sound at least as good after as before. Equally, options which sounded "better" were rejected if they compromised any aspect of technical performance. That bit separated Thiel from others. We required that every advance had to meet listening and measured criteria and if both were not simultaneously satisfied, then we went back to work. Our development cycle, even with successive learning, took years in the beginning and by the mid 90s was down to 9 months (like a baby), and that was a magnificent accomplishment, and orchestration, considering the extreme rigor involved.
Our listening room at the factory was in the lab, but nearly every night the product under development went home to the Georgetown Road farmhouse. We knew that room thoroughly well and it was a good room. I've mentioned the dimensions. Nice, not square, 10' ceiling, 45° bay windows, doors in the corners for bass vents, gypsum plaster on wood lath. Pretty sweet. We also used some other rooms including a plaster on brick with 12' ceiling in a downtown Victorian. Before 1990 we built the listening room at the factory. Soundproof. Quiet. Stiff walls and ceiling. Coves above lighting valence at the top edges. 12' high x 19.5' wide x 27' long - controlled decay dimensions, big enough that demure sound panels could control reflections. A truly lovely, neutral room which became the principle aural lab and demonstration room. We hosted many dealers, reviewers and other interested parties there. In 2012 I visited when the 2.7 final prototypes arrived. What a sweet reverie comparing them to 3.7s and 7.2s with the serious drive train in that room that I had built. I loved it. And I may not be participating here had that visit not happened.
I think that tells you much of the tenor of the undertaking. It was both scientifically serious as well as holistically grounded. It remained focused on music and its requirements while satisfying the demands of scientific engineering. For a small self-funded enterprise, it was genuine and rigorous beyond what any visitor imagined. And there were visitors from universities and large companies you would recognize. They invariably asked 'how can you do this'? And the answer was "because we love it'.
Such is the longer personal telling of Thiel's approach. The details would fill a book. I hope this narrative provides enough for you to appreciate some of what went into creating those speakers through which you enjoy your music. "For the Love of Music" was our first motto.
