Grand design released by one the biggest loudspeaker OEM suppliers in the world.
Designed by Hiroyuki Yoshii, the Grand Scepter was to be the most linear and coherent horn loudspeaker ever made.
Marketing-wise, its companion was the equally grand M-510 Grand Integra monster powerhouse. For, despite being a horn + compression chamber design, the GS-1 isn't that efficient.
And although both units got rave reviews in Japan and were launched at a moment japanese high-end really was booming and selling well, the GS-1 didn't sell that much.
It obviously wasn't meant as a bean counter recipe but it was and still is an x-rare little monster.
Besides price (1,000,000¥), weight (117kg) and diminutive sizing (106 x 63 x 61,5cm), the GS-1 proved to be somewhat difficult to power, due to a fairly complex internal filter/crossover : the latter scales efficiency down to 88dB while using an external crossover/filter allows the GS-1 to shoot up to 100dB - big difference !
If released in late 1983 in Japan, the GS-1 got known (and somewhat exported) outside Japan much later in the 1980s : so much so that many people believe the GS-1 to be an early 1990s design :)
Hiroyuki Yoshii in 1996 founded Time Domain which you can see here, alongwith technical papers aplenty regarding time alignement, time domain distortion and more time domain notions.
Much more on the GS-1 later on : many more images, detailed views, specifications, response curves, ads and even the numerous prototypes and prototyping which happened before 1984 - stay tuned !
The images on this page come from various japanese ads (Onkyo published many throughout the 1980s), a special Stereo Sound 1984 "Big Sound "section and Coty Award section.