Ericglo said: "Did you read the whole article or just the clip?"
What a lot of words! An interesting survey of technologies over the years, with lots of opinions on the audible consequences but a serious lack of (a) trustworthy measurements and (b) unbiased listening evaluations. He would learn from the measurements in my book, especially Chapter 18. He seems to think we hear waveforms.
"What do you consider the most significant advancement(s) in speakers over the last twenty years?"
Check out the figure attached to my post #50
and I think it is obvious that the 30 year progress has been in the refinement of transducer performance combined with better, computer aided, system design. Computer modeling figures powerfully in all of this. Good results require a faith in the existing science, not golden ears.
"What research has been most interesting, significant, impactful?"
At the risk of tooting my own horn, I would like to think that the most consequential research has involved meaningful double-blind listening tests, combined with accurate and comprehensive anechoic data on loudspeakers. The correlation between the two domains is strong. Few - almost nobody - in the industry has had the facilities, time, money, etc. to do the necessary research that has now nailed down the basic performance targets for loudspeakers that listeners reward with high sound quality scores. The Canadian government and then Harman International invested in the problem and the results are published for all to see The problem is that such measurements data are so scarce. See the Figure attached to my post #220
"what areas of research do you consider important, interesting, etc going forward?"
The source of greatest variation in what we hear from the best loudspeakers is in program material, the circle of confusion is real. We need psychological research into why so many people - professionals and consumers - are science deniers. Too many choose instead to follow their own sighted, biased, opinions of the moment, or the stylish writings of subjective reviewers who do nothing defensible in their subjective commentary and, for the most part, do no useful measurements. If we made absolutely no progress in loudspeaker design beyond where we are now, that alone would elevate the standard of sound quality everywhere.
A second line of research would be to explore methods of delivering more credible spatial illusions from two channels, which it seems we are stuck with for life. Flexible multichannel upmixing directed by metadata in recordings may be a practical route.