I was a tech in R&D for ESS for 1.5 yrs. '77-'78. The company was long past the electrostatics by then. I hired on there so I could afford a pair($450 ea.) of what I believed were the best sounding speakers in the world. Don't have all the answers for your questions, forget the 'statics they were before my time and did not compare with the Heil AMT.
I helped with the proto-types of all of the systems at the time including one special one called the Transar (full range Heil AMT). I left the company with what may well have been the best pair of speakers to that date: 1978 AMT1B Bookshelf built in the lab by myself with hand tested
I helped with the proto-types of all of the systems at the time including one special one called the Transar (full range Heil AMT). I left the company with what may well have been the best pair of speakers to that date: 1978 AMT1B Bookshelf built in the lab by myself with hand tested