Oh my, your one of us old timers!
When i worked at Intersonics inc, after "fixing" my Boss's esl-63's, the rule was i could pursue loudspeakers on the side BUT I was not allowed to use conventional drivers.
As my job was building acoustic levitation transducers and other transducers for the NASA and research side and I was building electrostatic drivers for fun, having to make Audio transducers was not a big jump.
The Servodrive sub-woofers and the Focused Field speakers were two of those. Eventually we made a large sonic boom simulator for NASA research which could play music too so that was in both sides of the ball park, science and audio haha.
When the space shuttle disaster happened, the work on a levitation system for the space station ceased and the company slowly went under.
The company hired a business consultant who was enamored with the loudspeaker side and suggested that had the best likelihood of succeeding.
He took on some investors and then shortly after fled back to south Africa with the money after having set up the business to make it look like my former boss was responsible with the IRS. .
That was the end of that business.
That whole time in my life was heartbreaking and it took a long time before I felt like working on the rotary loudspeaker technology or doing any government work. The Servodrive and the Rotary motion variants like the phoenix Cyclone below (made under license) and the Focused Field were examples of rotary loudspeakers.
My partner at DSL is keen for me to resurrect the Focused Field speaker you mentioned. I am going out of town with him later today and will bring that up.
Best,
Tom