Kimber Offshoot DiAural Promises Loudspeaker Renaissance

In the classic textbook example, the Doppler effect is demonstrated by an increase in both pitch and volume (or amplitude) of a train's whistle as it approaches a station, followed by a decrease in pitch and volume as it moves away. This effect---the shift of a frequency emitted by a moving object---leads to a fundamental flaw in audio technology. A midrange driver behaves like the approaching-and-departing train when it attempts to reproduce varying frequencies. When the driver is fed simultaneous 400Hz and 2kHz tones, the forward movement of the cone at the lower rate modulates the 2kHz tone upward in pitch and amplitude; when it moves backward it modulates the higher tone downward. (The human eardrum also behaves this way, but the brain's audio-analysis circuitry knows how to deal with it.)

The resulting distortion is one reason why hi-fi playback sounds less like real music than it should. Most studies indicate that the level of Doppler distortion must be quite high to be audible---which is exactly what happens with very complex, highly dynamic musical material. The wider the disparity in frequency and amplitude, the less like real music the reproduction sounds.

"That's why you hear only small jazz groups or simple instrumentals and vocals at hi-fi shows. The stress on the loudspeakers is relatively benign," says Kimber Kable's founder, Ray Kimber. "No one in his right mind ever plays heavy rock or orchestral music for a demo." Recorded music is heavily "scrambled" or "Doppler-encoded," he says, and the "bigger" the music, the more pronounced is its encoding.

The reason full-range speaker systems usually sound better is that they do a better job of decoding, but whatever decoding any speaker system does is purely accidental, Kimber explains. Multi-driver speaker systems can reduce Doppler distortion somewhat by limiting the frequency range of the individual drivers, but the effect is still present. No one has ever found a way to overcome this inherent problem.

Until now, possibly. Kimber claims to have a novel, incredibly cheap ("$2 worth of parts") cure for one of audio's oldest obstacles. He calls the cure "DiAural Doppler decoding," and has teamed up with WordPerfect founder Bruce Bastion to license the technology to loudspeaker manufacturers worldwide. The name has been registered as a trademark, and patent approval is expected soon. The startup company has signed non-disclosure statements with at least 100 loudspeaker manufacturers, who are presently evaluating the technology.

Bruce Bastion is a new name in high-end audio. Kimber says he is "a musician and audiophile with great ears, a guy who's obsessed with great sound. He's spent more on audio in his lifetime than most people have earned in two lifetimes." The two are financial partners in DiAural, but the invention is actually the work of electronics designer Eric Alexander, whom Kimber describes as "an audio enthusiast with an unprecedented level of passion and inventiveness."

"I first heard Doppler decoding at Eric's house," Kimber recalls. "I heard rock-solid, three-dimensional imaging coming from a rather ordinary-looking pair of homemade loudspeakers, even though I was way off-axis. I was stopped dead in my tracks. The effect was like a self-correcting room acoustic equalizer, but far better. I was shocked. I've been around this business most of my life. It takes a lot to stampede me, and quite frankly, I was stampeded."

Kimber immediately began arranging to get the technique patented, enlisting the services of a 20-partner patent law firm in Salt Lake City. An exhaustive patent search revealed that the DiAural process had no precedent. "When you see it, you'll wonder why nobody thought of it 50 years ago. It's that obvious," he says. "And from every basis---theory, measurement, subjective evaluation---it works." Approximately 100 people heard what Kimber called "a crude demonstration of a truly remarkable technology" at the most recent CES, after which he was accused by an unnamed critic of "perpetuating a psychoacoustic hoax."

Despite the technical simplicity, DiAural, the company, will come down hard on anyone attempting to rip off the design. "We are pricing the licensing fees at an affordable level so that everyone can benefit," Kimber says. The basic fee will be an annual $1000 paid in advance, with a surcharge of ten cents per pound of loudspeaker.

A fee based on weight may sound silly, he admits, but it was the only way they could figure out how to be fair to everyone. Thus, a 50-lb DiAural-enhanced speaker will cost a manufacturer an extra $5; a production run of 1000 units will cost $5000 more. Licensed manufacturers will be issued revenue stamps to affix to their products as proof of authenticity, like Dolby's double-D insignia or Lucasfilm's THX logo.

Hobbyist speaker builders will be able to buy the technology from authorized resellers, Kimber notes, cautioning that "upgrade shops who try to steal this are going to feel our wrath." To put some teeth into this policy, he decided that "licensing fees paid after the fact will be $50,000."

Kimber says that adding DiAural circuitry to a loudspeaker "may sound more expensive, but we expect to actually save manufacturers money," stressing that the process "eliminates many crossover components, improves dynamics and power handling, and increases reliability." License agreements will be available after April 5. Kimber requests that all applications and inquiries be made in writing through DiAural's fax number: (801) 627-6980.

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