In response to Trelja's question - the crossover of the orignal ESS AMT speakers was set at 1,000 HZ. The most recent version use 800 HZ. The Swiss made Oscar Kithara has a crossover at 730 HZ. While the ESS speakers had midrange problems, I'm not sure why anyone would hate these speakers. The clarity and openess of the Heil puts a lot of high dollar speakers to sham and works wonderfully for a lot of rock and electronic music. The midrange deficiencies of the ESS designs caused by blending a large slow woofer with the ultra fast Heil just made the ESS a poor choice for jass and vocal enthusiasts. I understand that some the recent designs that use the Heil do not have this midrange problem. Alas they are not easily avaialbe in the U.S. The Swiss company Precide distributes the speakers.
ESS speakers "Translinear" Transstatic
These were speakers designed by California based company called ESS, that is, Electro Static Sound before they used the Heil Air Montion transformer. These models were current in 1970-1975. I am curious if any one still owns either of the above models, or has seem them listed on any of them listed in the used audio web sites. They were incredible speakers for their time,and sounded as good as many of so-called elctrostatics of today. They used good driver elements, for example, the KEF B-139 oval driver for the bass response.If anyone has knowledge of either of these above vintage speakers,please leave info on this Web page. Thank you!!