Some historical remarks..
- In
1954 Villchur introduced closed box (acoustic suspension) which gained popularity in slowly growing hifi market. Response 50-10 000Hz. This cult has revived best in Britain (BBC heritage).
- in '70s
electrostatic panel speakers didn't get much popularity.
The popularity of the acoustic suspension speaker was due to size restrictions. Hitherto, any reasonable semblance of bass response required a largish box, or an even larger horn-type enclosure. The trade-off was that the acoustic suspension speaker was not very sensitive, requiring more power than the 'average' amplifier of the day could provide. Bob Carver's Phase Linear company was one of the first to provide suitable domestic oriented power amplification that could make the AR3 and it's ilk actually 'come alive'. Things quickly progressed, and by the late '70s watts were so cheap you could buy all in one receivers from any of the major Japanese brands sporting 150 watts/ch, and more. By then, however, the acoustic suspension engine was almost a thing of the past--you'd never find the Maxell 'blown away' guy sitting in front of an AR3a.
The earliest US electrostatic speakers were often smallish box hybrids (sealed woofers) or separate, add-on electrostatic tweeter panels, such as the Janszen. KLH and Infinity had a go at it--both were monsters and costly. Quad was more or less reasonable, price-wise, but never had much of a US presence. Bud Fried imported them for a while, however I've no idea how many he sold. Really, they just didn't fit the American listening style. Gordon Holt complained about their lack of power handling; Peter Aczel owned them several times, said they were excellent, but only for low SPL, single listener use (due to beaming). In order to overcome some of their limitations, Mark Levinson stacked them, added a monstrous subwoofer and tweako tweeter, all in the hopes of pushing out some decent SPL. Then he raised the price to oil sheik levels, and shortly thereafter went out of business.
I think the company that did most to popularize electrostatics was Jim Strickland's Acoustat organization. Acoustats were relatively affordable, relatively indestructable, required a relatively powerful amplifier, but offered relatively pleasant and relatively loud sound. My guess is that Acoustat sold more electrostatic speakers than anyone. But even they couldn't make a go of it, lasting a little while longer as a subsidiary of David Hafler's company, subsequently absorbed by car speaker outfit Rockford. I heard the brand was later sold to some Italians (that is, a company in Italy) who sold it to an outfit in Guangzhou China.