Wondering outloud here: The biflex cone was designed for controlled breakup, even having a suspension in the middle of the larger cone. Why aren't there more single driver speakers made using this arrangement? There are plenty of speakers with whizzer cones, but why no modern drivers with biflex cones too? Surely it isn't cost prohibitive, look at Lowthers. Cost no object, wouldn't you want a biflex cone maybe with a whizzer too? Any of you done anything with vintage biflex drivers like the Altec 412, 415, 419 or 420?