Your illustration in the book was enough for me to see what you are trying to achieve, and you provided a cursory explanation but you really only dedicated a couple pages to the subject. That may be all that is required to conceptualize it mathematically, but I'd like to see it explored in more detail.

My hunch is that it would be best used in bass subsystems, because of its mass. In that regard, it seems like a relatively small area radiator could be coupled to a much larger radiating lever membrane, on the order of areas similar to a basshorn. That might provide the efficiencies of a horn, but without the peaks from being undersized as basshorns almost always are. It has very intriquing possibilities.

Might be worth asking Eminence to build one, since they are setup to do it. Then again, maybe you can get a better deal through your contacts at B&C. But either way, I'd love to see tests of a few samples made with various size primary and secondary diaphragms.