Some highlights for me:

I love it, in the context of the old penchant for Bose-bashing in these forums, that GT seemed intrigued by the basic idea of the BOSE 901 and said that if the shortcomings had been addressed, it could have become quite an interesting speaker. That is: 1) use higher quality drivers; 2) provide some decent-sounding electronics in the EQ box; 3) change the front single driver into a two-way with a tweeter because there is no way to get any decent treble by EQ'ing a five-inch full range.

I liked hearing GT confirm one of my own biases, that tube amps are complementary to compression drivers and horns in some way that has not been fully explained (to paraphrase: because of the differences between the way tubes and solid state devices work).

I liked that he allowed as how he "still" didn't know why some electronics seem to have good sound stage depth and others do not.

I found his description of the 4660 horn design fascinating and also that the same ideas are included in the design of JBL's latest horns.

I have long wondered about the risk of doppler distortion in the Tannoy coaxial, but I had never before seen the problem addressed. He also seemed to suggest that the projecting treble coaxial horn is so fraught it is beyond problematic.

In talking about patents in audio and acoustics, he said that many recent patents have been awarded because of inadequate research of prior art and prior writings (Olsen in the 1920's) and that therefore the patents are not actually valid. He said that at JBL they sometimes thought it better to not patent something because then no one would know about it. He also said they did not try to protect some things they did because they were so expensive no one else would dare try to copy them—like close tolerances in compression drivers that led to yield problems, but making the gaps more relaxed caused frequency response anomalies which could not be remedied other ways. This makes me think of past conversations here about apparently unused drivers that people were buying on eBay.

He has worked to get time alignment and linear phase in his music system. Though he does not say this explicitly, I think that for him these are the persuasive possibilities of digital electronics past the front end sources. I liked that he notes differences in digital music products when that does not seem strictly possible in the digital domain; this is an old conversation between my son and me.