I heard the prototypes last year, which were a slightly modded Eminence Alpha 12 and a bullet tweeter mounted coaxially. They sounded impressively good. These new drivers are better all around, with a very clean sounding coaxial horn crossed at 3.5 kHz. The designer, Darrel Hawthorne, had these made to spec just for OB use.I might modestly add that my EV open baffles may have triggered the spark of interest in getting Darrel interested in OB's. He heard them last year at a little mini audio fest at another friends house just South of Lansing. I think he was rather blown away by the OB sound. These new drivers outperform my old EV LS-12's in every way.
I'm amazed at the articulation and smoothness coming out of a 15 inch driver. I don't think I could recommend a better sounding woof/tweet combo for anywhere near the price that would work well in an OB. It's going to be a long time before I switch drivers again.
Dave