The June issue of Hi-Fi World has a report of this year’s HiFi Wigwam show at Scalford. In an attic room there was a demonstration of an audio system called “Quad experiment”.
It comprised four equi-spaced Quad 57 electrostatic speakers turned through 90 degrees, so the nominally vertical panels were horizontal. A Class D power amplifier fed each speaker.
The really interesting aspect was that the signal for the left-hand channel was fed across the sound stage, to the three speakers on the right, with the signal being progressively attenuated and delayed. The signal for the right-hand channel was similarly fed across the sound stage, also progressively attenuated and delayed.
The show report claimed the imaging was “awesome” the bass was "strong" without any cabinet resonance; in fact the system was described as “stunning”.
The idea of sequentially feeding both the left and right signals to electrostatic elements using delay lines is not new. Peter Walker discussed it in his Wireless World article of 1955, and of course a similar idea was employed in the Quad 63 and in all later ESL designs. But this is the first I have heard of anyone trying out the idea using Quad 57s.
Did anyone visit the “Quad experiment”, and if you did what were your impressions? I really would like to know, as it is a scheme I would be interested in trying out for myself.