As I write these words in January 1991, we're right in the midst of an annual media feeding frenzy: the "Best of the Year" follies. This usually takes the form of lists compiled in groups of ten for reasons that must hearken back to some obscure Druidic practice. You know the routine: "Ten Best Books of the Year," "Ten Best Films of the Year," "Ten Top Personalities of the Year," "Ten Best Sports Plays of the Year." Every corner of the media seems eager to get into the act. Special-interest magazines are hardly immune. Car enthusiasts can get their fill of "Cars of the Year." Computer literates find their favorite rags full of the "Ten Best Computers/Computer Accessories/Computer Programs." And music magazines regale us with the "Ten Best Recordings of the Year." Everyone with access to a transmitter or printing press has got, it seems, a little list.
Stardate: 3087.6. Location: somewhere in the 4th quadrant. In response to Captain Kirk's orders, Mr. Sulu throws a few well-chosen levers and sliders—not much different in design and function from those used by Flash Gordon and Captain Video—to redirect the Good Ship Enterprise where no man has boldly gone before. New adventures begin immediately after the bridge crew pick themselves up off the deck and nonchalantly resume their stations.
Michael, who might be termed our typical audiophile (if anything in Santa Fe can be termed "typical"), may have found his digital processor, but he's still in a quandary about choosing the right power amp to drive his new loudspeakers. He has listened to a number of them over the past few months, and has been unable to find one which satisfies him in every way. I suspect he has a lot of company. The thorny problems of room acoustics and placement aside, loudspeakers are easier. Their signatures are pronounced and generate strong feelings one way or another; it's usually no problem to narrow down one's choices in this category.
In the late 1980s, KEF, then as now a leader in bringing new technology to loudspeaker design, developed a unique coincident driver that positioned the tweeter in the throat of the midrange/woofer cone. In a flash of inspiration, they dubbed it the Uni-Q, and the driver immediately not only found its way into the company's more upscale speaker designs, but also became a key element in a major European research project on room acoustics. That study's results appear to have been inconclusive, but the Uni-Q lives on as the defining element of KEF loudspeakers.
By now most readers will be familiar with the relatively new tuned-cavity method of low-frequency loading. Such designs have popped up all over the place of late, especially in those little satellite/woofer systems, but KEF can rightly lay claim to generating the design's theoretical basis, as JA described in his review of the KEF R107/2 loudspeaker in Vol.14 No.5 (May 1991). Essentially, the technique consists of loading the rear of a woofer in a conventional fashionusually a sealed boxbut also loading the front of the driver into another enclosure, ducted to the outside. Basically, the design acts as a bandpass filter with its response centered on the port-tuning frequency. The rolloff is smooth and rapid on either side of this frequency, providing a natural low-pass characteristic but thereby virtually mandating a three-way system. If properly designed, this configuration offers a number of theoretical advantages. The radiating element is actually the air in the port, which is low in mass. Low distortion is possible, as is relatively high sensitivity.
The Model Four is the largest model in KEF's current Reference series of loudspeakers, discounting the R107/2 Raymond Cooke Special-Edition (reviewed in a follow-up in October '95). It's also the largest KEF model that uses their Uni-Q® loudspeaker configuration. When I visited the KEF factory last October with a group of audio journalists from the US, KEF emphasized the importance of Uni-Q technology to their future plans. They consider it proprietary, and intend to enforce the worldwide patents they hold on the design. One look at KEF's current line will be enough to tell you why they're so serious. Uni-Q drivers may be found not only in most of the Reference series, but in most of their other models as well. The most significant exceptions: the Raymond Cooke series, a few inexpensive models, and their THX-certified loudspeaker system.
Since he joined Snell Acoustics in the mid-1980s, Kevin Voecks, their chief designer (footnote 1), has been involved in the design or redesign of the entire Snell line, from the minor revision of the Type A/III (incorporation of a new tweeter), to the complete redesign of the Type C (now the CIII). Snell Acoustics is located in Massachusetts, and although Kevin spends a good deal of time there or at the measurement and analysis facilities of the Canadian National Research Council (NRC) in Ottawa, he does a great deal of his conceptual and preliminary design work, as well as his listening, in Los Angeles, where he makes his home. I visited him there last summer to gather a little insight into his background and loudspeaker design philosophy. I started by asking Kevin when had he first become interested in loudspeaker design...
Kinergetics Research was a name to be reckoned with in the early days of CD, when they produced some of the earliest well-received, audiophile-grade CD players. They've branched out since then, producing amplifiers, preamps, subwoofers, and surround-sound processors. In fact, they're so busy with such products that they no longer build CD players! The last Stereophile review of a Kinergetics CD player appeared way back in 1993.
Love 'em or hate 'em, headphones serve a purpose. My first headphones were Kosses, and they were perfect for use in a college dorm. While I've always owned a pair or more over the years, somehow they never became my primary mode of listening, except in situations where using loudspeakers at satisfying levels risked eviction, bodily harm, or both.