I was reading about how to build a capacitor checker from the December 1959 issue of Popular Electronics and stumbled across something that looked very familiar.
I know that shape.
Nearly identical to a Bose® 901 Series I/II cabinet, and even specifically references expanding the sound field with a reflected wave. The 901 series uses what Bose calls “Direct/Reflecting” technology.
Anyone know about these “Cosmos Industries” speakers? Does anyone know any of their names, who might have gone on to work for the early Bose® corporation?
RETROVOLTAGE 
Hi,
Don’t know anything about the speakers or who built them, but did find one thread on Audiokarma that briefly discussed them:
http://www.audiokarma.org/forums/index.php?threads/the-ah-electrostatic-speakers-bose-901-look-alikes.111461/
Thanks Mike, very interesting!