Here we have an Australian room that demonstrated the best A/B/C comparison at the show. The center piece of the whole demo is the DEQX HDP-5 Preamp Processor ($6499), which provides DSP room correction, digital crossover ability, and "Loudspeaker Calibration" for detailed phase response and frequency response corrections. Alan Langford of DEQX explained to me how he had setup the system to offer three perspectives:
1) speakers passively tri-amped using the stock 6dB/octave filters.
2) Speakers actively tri-amped using the 96dB/octave digital filters in the HDP-5 along with DSP driver calibration corrections.
3) Adding DSP room correction as well.
Alan chose VAF i93 Mk. II speakers ($16,000 per pair), and three Redgum amps, along with the complicated wiring and relays to pull this room together, and keeping everything from Australia. The demo I enjoyed had a female vocal from an Opera, and Stevie Ray Vaughn’s "Little Wing". First I listened to the non DEQX passive VAF system, decent, vocal images too large and soundstage too small. Then Alan added the active crossovers and driver calibration, much better with tighter vocal images, bigger soundstage, better control in the bass. The coup de grace added DEQX room correction and the same music sounded incredibly better. Vocals at the right height and size, soundstage much deeper and wider with layering, the bass was tighter and seemed to extend deeper, and a general haze was removed allowing for a clearer and more focused window on the music. This demo showed how much proper DSP can improve a system / room and result in a more musical presentation, congratulations Alan and DEQX on a really great sounding room.