Pssst, Scott; Babb's patent permanently expired today

I was 16 and didnt even know what soundstage or point source was, when that guy filed the application. I was thinking "All I know is the tweeter needs a 4uf NP cap" while this guy "Each subsection of the coil is centered on the boundary of the magnetic flux field so that as one subsection moves into the flux field, the other subsection moves out of the flux field at the same rate".

I didnt even know anyone who set their speakers 8 - 10 ft apart at one end of the room back then. I remember one guy hung his Bose 501s from the ceiling - and I thought that was just so cool.
 
Seen/auditioned 901s in various layouts including suspended, but can't recall ever noticing any of the other product line except the original Acoustic Wave Music System that quite a few folks found $800 [IIRC] [~$2033 today] a fair price/performance ratio.

Anyway, the Lorelei Babb prototype that interests some of us is for lack of a better description, a true compact 'full-range' 4th order compression driven point source horn with an ultra high, spiderless 1" [1.2"?] Xmax combined with at least a 400 W peak power handling to offset its abysmal efficiency, controlled directivity out to ~140 deg [IIRC] and like all Babbs, a waterproof design for marine apps.

GM
 
I see a frictional o-ring there. That’s going to have a hard time moving at 20kHz without a lot of heat friction. Also, a large stroke piston air pump to a horn is what this is. I am not sure the sound is going to be very hi-fi. Also, 1inch stroke at 20kHz is 504m/sec that’s above the speed of sound. About Mach 1.5. Compressible flow regime.

Has this ever been made into a good sounding driver for hifi audio?
 
I see a frictional o-ring there. That’s going to have a hard time moving at 20kHz without a lot of heat friction. Also, a large stroke piston air pump to a horn is what this is. I am not sure the sound is going to be very hi-fi. Also, 1inch stroke at 20kHz is 504m/sec that’s above the speed of sound. About Mach 1.5. Compressible flow regime.

Has this ever been made into a good sounding driver for hifi audio?

Oh yes indeed: as GM noted, the Lorelei is rightly regarded as one of the finest wideband drivers ever built. Arguably 'the', with the partial exception of some of Olson's big [partial coax] units, which were functionally an inverse approach & significantly larger. Alas, the company as-was couldn't survive the financial crash and very few were made to the original / prototype spec. As a result, not many people have even heard about them.