I think it was at least a couple of years ago that I first heard that Atlantic Technologya speaker manufacturer that I associate more with value-for-money than cutting-edge productswas working on a patent-pending technology that combines reflex, acoustic suspension, inverse horn, and transmission line approaches to bass loading. Dubbed Hybrid Pressure Acceleration System (H-PAS), this is said to combine the best aspects of each approach, with deep bass extension, good system sensitivity, and reasonable enclosure size.
Well, the patent has been granted, and the floor-standing AT-1 ($2500/pair) is the first speaker to utilize the H-PAS approach. (According to Atlantic’s Peter Tribeman, they have licenzed H-PAS to five other companieswhich he understandably declined to name.)
Having listened at CES to a pair of AT-1s, in a system that included top-of-the line Halo by Parasound electronics, I’m convinced that they’re on to something with this technology. The AT-1 is a modestly-sized floorstander, with two 5¼” woofer/midrange drivers, and yet it generated bass of such extension, power, and control that left me and others who attended the demo shaking their heads in disbelief. The sound was otherwise fine, too: tonally well-balanced (the bass was there only when it was on the recording), and a precisely-defined soundstage. Most impressive.