Prof - From the beginning in '74-'75 the goal was to find the best platform on which to build a line. We investigated (translate designed and built) spherical arrays, line sources, panels, folded horns, powered multi-driver speakers, and I may be forgetting a few. Phase coherence was in the list of goals, but not found to be practical. The first real product to take shape, the Model O1, incorporated what we could achieve in practical terms within our constraints. Its strengths were very high efficiency (94dB?) with its equalized sealed box bass, built on a custom driver by Eminence, who built stage drivers for Peavey and others. That driver had a huge magnet, good thermal management, long excursion and good linearity, but with a normal, overhung voice coil; the best that we could find for our needs. BTW, better than SEAS, Dynaudio, etc. The tweeter to match was a Long Engineering 1.5" mylar dome with good performance. Jim messed with first and second order filters for that product and landed on 3rd - 18dB slopes as the most practical solution. It was fairly linear, bass below 30Hz and a not too refined treble in a medium bookshelf package in all the wood finishes Thiel became known for.
We gathered a following, especially due to some serendipitous European export opportunities. Dealers wanted a more refined, audiophile product and Jim developed the O2 as a response to demand more than his own ambition. It was a ported 6.5" Seas treated paper woofer under a 1" Peerless silk dome with second order slopes. It delivered a more refined presentation, trading off bass response and some efficiency. I think it came in around 90dB and served as a stepping stone into the emerging audiophile market, which really hadn't gelled yet.
By 1977 we had attended our first CES and had enough distribution to figure out that we had to do something unique, memorable, extraordinary to carve out a meaningful niche. The next year and a half of extreme difficulty went into developing the O3 as a minimum phase transducer. We went to our second show with a second order O3 as backup because EVERYTHING mattered so much more when phase coherence was added to the formula. There were deficiencies that were later solved. We mustered our courage and presented the Minimum Phase version, having the rectangular normal tower in the closet, just in case. The response was overwhelmingly positive, and we never looked back to normalcy.
That sounds smoother than it was. We faced another year of tracking down weird stuff such as magnetic eddies, wire anomalies, diffraction and so forth, all of which were sonically invisible with high order filters, but glaringly obvious with first order. The ear-brain interpreted the sound as "real" and held it to a higher standard than regular canned sound. That's a big subject, but I must sign off for this evening.
We gathered a following, especially due to some serendipitous European export opportunities. Dealers wanted a more refined, audiophile product and Jim developed the O2 as a response to demand more than his own ambition. It was a ported 6.5" Seas treated paper woofer under a 1" Peerless silk dome with second order slopes. It delivered a more refined presentation, trading off bass response and some efficiency. I think it came in around 90dB and served as a stepping stone into the emerging audiophile market, which really hadn't gelled yet.
By 1977 we had attended our first CES and had enough distribution to figure out that we had to do something unique, memorable, extraordinary to carve out a meaningful niche. The next year and a half of extreme difficulty went into developing the O3 as a minimum phase transducer. We went to our second show with a second order O3 as backup because EVERYTHING mattered so much more when phase coherence was added to the formula. There were deficiencies that were later solved. We mustered our courage and presented the Minimum Phase version, having the rectangular normal tower in the closet, just in case. The response was overwhelmingly positive, and we never looked back to normalcy.
That sounds smoother than it was. We faced another year of tracking down weird stuff such as magnetic eddies, wire anomalies, diffraction and so forth, all of which were sonically invisible with high order filters, but glaringly obvious with first order. The ear-brain interpreted the sound as "real" and held it to a higher standard than regular canned sound. That's a big subject, but I must sign off for this evening.