Today the sad news about the passing of Jim Thiel was announced. On the few occasions that I met Jim he was always very gracious. I can't think of anyone in the audio business that I respect more. He will certainly be missed. Like many others I'm sure, I only wish that I could have known him better.
The Thiel philosophy holds, among other things that a speaker should be time and phase coherent. Phase coherence is when two drivers in a speaker are working to create the same frequency and they are doing so by moving in unison. Time coherent means that the sound from each driver arrive at the listening position at the same time, which is made possible by the sloped baffle of his designs. The third major component to all of the recent Thiel designs was short voice coils held within a long magnetic gap. This arrangement has the advantage of keeping the voice coil of a driver within the magnetic field of the gap and dramatically reducing distortion.
To learn a lot more about the innovations and views of this founding father of high-end audio check out the following interviews. Also of interest is the March 1998 Stereophile interview conducted by .