Interesting... the whole concept makes perfect sense. It's a variable pitch blade coupled to a constant RPM motor. This technology has been around in aircraft for decades. Basically the blades of the prop rotate to take a "bigger bite" out of the air. On the C-130, the props can reverse entirely so the plane can back up under its own power!
Since a speaker is more or less just an air pump that rapidly changes the air pressure in a room to produce sound (ever wonder what it's called Sound Pressure Level??)... then why can't it be done with a variable pitch fan that adjusts the prop blades according to a certain frequenty to alter the air pressure inside an otherwise semi-sealed room by flowing extra air either into.. or out of the room through a ductwork system??
Ever notice how an almost closed door will slam shut in a room when the A/C kicks on?? This setup would be VERY loosely akin to the A/C kicking on and off 20 times per second or so.
I like it!! :thumbsup: