I'd like to add two brands to my list of horns mentioned in my "Why Not Horns ?" thread. They are SP Technology and Emerald Physics. Neither of these co. are advertising themselves as horns...but they qualify in the two major ways which define a horn. One is the use of a compression driver for the midrange and tweeter. SP's starts at 700 Hz while Emerald's begins at 1,000 kHz. Plus, they both use a "waveguide" - which technically speaking, is a horn.
I'm doing this out of love of music and how I think that rear-loaded horns do a much better job at revealing music's contrasts, decay, acceleration and SPL output than *any* direct-radiator. All of the recent reviews and/or show reports of these systems have been over-the-top, to say the least.
Horns join "open baffles" as the latest, hot trend in dynamic speaker design. Most promising, is the *fusion* of these twin advancements into one neat package. There are, I count, three co. making "open horns" right now. Emerald Physics doesn't count because it is a horn above 1,000 kHz but "open" below 1,000 kHz.
Finally, it should be noted that Vandersteen, as reported in the latest TAS Buyer's Guide, is not open-baffle, as it is not a dipole.