RMAF 2007

I was utterly intrigued by the innovative speakers from Dr. Shelley Katz’s UK-based Podium Sound ($5995/pair). Katz produces panel loudspeakers that mechanically vibrate via electromagnetic drivers. Inherently free from phase error and less sensitive to placement than electrostats, they operate full-range without any filters.

Nelson Pass is up to good again. Following the wonderful sound of Ella and Billy I heard in the corridor, I discovered Nelson's prototype open-baffle speaker system. It sports both a Lowther PM6A full-range driver and a pair of SEAS W26 10" woofers. The 40"-high open baffle, which at this stage of the game is not intended to be a final design statement, has no side panels, only a central brace in the rear. The system was bi-amped, with the Lowther driver fed using a 60Hz, 6dB/octave high-pass filter feeding a First Watt F3 7Wpc JFET amplifier. The woofers were driven by a Pass Labs XA30.5 fed by a 12dB/octave active crossover. No equalization was employed. That the sound was so good was especially amazing, considering that the digital front end was pieced together at the last minute after the originally intended computer drive arrived minus its charger chord. I look forward to hearing the finished product.

The fourth annual Rocky Mountain Audio Fest is taking place this weekend at the Denver Tech Center Marriott. Registration was up 15% this year; snapped in the line in front of the registration desk at 9am was erstwhile Stereophile staffer Jonathan Scull (sensible suit, smart tie, and flashy glasses), these days a successful PR and marketing consultant.