KEF Turns 50: A Retrospective

KEF Bextrene B110,
KEF Calinda,
KEF Cantata,
KEF Celestes,
KEF Corelli,
KEF Cresta,
KEF KHT 3000,
KEF LS3/5a,
KEF Mylar T117,
KEF Turns 50: A Retrospective

 The name KEF perhaps perfectly encapsulates founder Raymond Cooke’s no-nonsense approach to making things. In 1961, engineer Cooke needed a factory to build loudspeakers, and the place he settled upon was the site of the former Kent Engineering & Foundry company in Tovil, Maidstone, Kent, in the UK. Rather than change the name, Cooke decided to call his new company “KEF.”

Raymond Cooke OBE (1925–95) was an engineer’s engineer. Starting his career as an industrial chemist with one of the main railroad companies in the UK, he joined the Royal Navy and spent WWII as a radio operator. Following the war, he was awarded a degree in electrical engineering and worked for the British Broadcasting Company’s then-prestigious Engineering Department, working under Dudley Harwood (later of Harbeth fame). Around this time, he met Gilbert Briggs of Wharfedale, helped edit Briggs’ books, and in 1956 became Wharfedale’s Technical Manager. It was there he discovered that the current thinking at the time, which held that deep bass needs large drivers, was not the only way. Cooke experimented at Wharfedale and found that lower efficiency and smaller drive units could deliver accurate deep bass, too. He was also convinced that improved performance was only possible using the latest in materials technology—in other words, drivers that featured diaphragms made of plastic instead of the near-universal paper cones found at the time.

When Wharfedale was sold to the Rank Organisation in the late 1950s, Cooke decided it was time to go it alone. He couldn’t have picked a better moment, since the shift from mono to stereo was becoming a hot topic among hi-fi enthusiasts, in turn creating demand for pairs of smaller, more accurate loudspeakers. KEF rose to the challenge with its first loudspeaker, the K1, which was a comparatively small three-way design, bristling with then-state-of-the-art technology, including foil-stiffened, vacuum-formed polystyrene diaphragms and a tweeter with a diaphragm made of Melinex (Mylar). This was at a time when almost every other loudspeaker had a doped-paper bass cone and, at best, a fabric tweeter.

Buoyed by the K1’s reception, by the mid-1960's, KEF used what it learned to deliver the Celeste, one of the first small high-performance loudspeakers ever seen in the UK. With the more powerful transistorized amplifiers beginning to appear, KEF’s use of new materials gained in popularity, and a pair of small KEF Celestes proved hard to better at the time.

During this same period in the UK, there was a still strong contingent of amateur loudspeaker builders who preferred to make rather than buy fully finished speakers. Among those builders, KEF enjoyed a commanding reputation as a drive-unit maker whose ever-growing portfolio of speaker drivers were known for their advanced designs and materials technologies. With sales running into the millions, KEF became the premier supplier of next-generation loudspeaker drive units, and that attracted the attention of Cooke’s old teammates at the BBC. Among the successes at the time, KEF’s ¾” Mylar T117 tweeter and 5” Bextrene B110 mid/bass cone driver, proved immensely popular both in the 1967 Cresta loudspeaker and with DIY’ers. They also formed the core of the BBC LS3/5 and—in later form—the legendry LS3/5a. In fact, KEF’s association with the BBC lasted from the 1960's until the broadcaster’s Engineering Department effectively closed in the 1990's.

From the outset, KEF established itself as a science-led company, and in the 1970s KEF was at the forefront of development in computer design, modeling, and acoustic research. The company was pivotal in the development of measuring loudspeaker frequency response using computerized Fast-Fourier Transform techniques. The company developed what it called a “total system design” structure, using digital techniques at a time when “digital” meant “counting on your fingers” for most people. This meant pair-matching drive units in loudspeakers to within half a decibel, therefore making far superior stereo imaging than most contemporaneous speakers. KEF developed the Corelli, Cantata, and Calinda ranges at this time.

In the middle of the 1970's, KEF was producing three-dimensional graphs that showed how loudspeakers behaved under “real-world” conditions—not simply with test tones—and the result of this endeavor was loudspeakers like the Model 104. This high-efficiency, high-output small loudspeaker used three innovative synthetic laminated drivers and proved extremely popular. So popular, in fact, that it sparked KEFs Reference Series, which continues to this day, undergoing a process of constant development.

In 1977 KEF introduced its famous Reference Model 105, which was the result of what was arguably one of the most advanced loudspeaker development projects ever undertaken. The speaker featured separate enclosures for the bass and mid/treble sections to allow time-alignment and even sound dispersion over the entire audio range, and featured fourth-order Linkwitz-Riley crossovers. The Reference Model 105 came to represent the highest of loudspeaker high technology and is still one of the best-known high-end loudspeakers in the UK. Little wonder then that KEF received two Queen’s Awards for Export Achievement in the 1970's, and Cooke himself received the Order of the British Empire medal in 1979.

The computer-modeling systems created by KEF in the late 1960's and early 1970's led to highly advanced Reference Series designs in the late 1970's.

Once again KEF and the BBC linked up in a fascinating experiment in 1980, with Abbado conducting the Berlioz Te Deum in the Usher Hall, Edinburgh, even though the piece used the organ of St Mary’s Cathedral a mile away. The organ’s recording was transmitted by FM radio link to the Usher Hall, where it was replayed successfully using 36 KEF Reference 105/2 loudspeakers.

KEF’s constant drive for technological innovation soon extended across Europe. In partnership with Bang & Olufsen and the Acoustics Laboratory of the Technical University of Denmark, KEF began work on the EUREKA Archimedes project. A very advanced computer-modeling-and-mapping concept, the idea behind EUREKA Archimedes was to develop a “smart” loudspeaker that compensated for its surroundings. This project ultimately helped develop pioneering digital-signal processing that would prove vital for delivering more accurate and deep bass from smaller loudspeakers. And, in the process, KEF developed its distinctive two-way Uni-Q driver array that features a tweeter positioned in the acoustic center of the mid/bass unit. This driver creates a virtual point source, and therefore delivers satisfying three-dimensional sound over a broad listening area—not just from one narrowly defined “sweet spot” between the speakers. During the 1980's, KEF’s popular Reference range helped the company make deeper inroads in the U.S. market and the company diversified into car audio and in-wall loudspeaker systems, long before the trend in multi-room audio emerged.

Raymond Cooke was elected President of the Audio Engineering Society in 1983/84, as well as receiving the Bronze and Silver medals from the society in 1980 and 1993 respectively. He retired in 1988, but was made Life President of KEF and played an active role in the company until his death in 1995, age 70.

The company was acquired in 1992 by Gold Peak Industries, an Asian multinational. This led to speculation about the future of KEF, in part because it was one of the first traditional audio brand names to be bought by Asian interests. But KEF would certainly not be the last British hi-fi manufacturer acquired by offshore owners, and in any event it soon became clear that the firm was in good hands. The company swiftly and deftly moved into home-theater markets, at first with the Model 100 center loudspeaker and subsequent development of THX-approved designs. (KEF was one of the first UK companies to seek THX approval, and Laurie Fincham, who joined KEF in 1968 and replaced Cooke as chief engineer at the company, is now Chief Scientist at THX.). At the same time, KEF recognized impending changes in the audio market, especially the European audio market, and designed the small low-cost Coda 7 loudspeaker for a new audience. It also continued to develop and improve its other ranges, including a major improvement in the Uni-Q line toward the end of the 1990's.

The first years of the 21st Century saw KEF catch the home-theater world unawares, with the launch of its KHT2005 sub/sat system, forever known as the “KEF eggs.” These small, ovoid loudspeakers, whose enclosures were made from cast aluminum, featured custom Uni-Q drivers and offered excellent value for money, which gave them far more spacious sound than their rivals. Once again, these loudspeakers were the result of extensive research and led to the development of new technologies, with the assistance of new Finite Element Analysis-driven computer-aided design systems. In home theater, one such development was KEF’s Acoustic Compliance Enhancement (ACE) technology that uses bass cabinet filler materials infused with activated charcoal to help control the flow of air within the enclosure at a molecular level. In short, ACE gives small cabinets the loading characteristics of much larger enclosures, improving bass depth and smoothness in the process.

Recently, KEF has been busy, with all-new Q-Series and R-Series loudspeakers, both of which feature Uni-Q technology developed to its fullest extent to date, while the Muon represents the first in a beyond-luxury series of limited edition loudspeaker products. Most recently, KEF has brought its elegant Concept Blade speaker—first seen as a pure engineering idea at the Munich High End show two years ago—into a new high-end design simply called the Blade that shows just how much good KEF can put into any speaker.

Fifty years on, and KEF still stands by the goals laid down by Raymond Cooke back in 1961. The company is driven by technological innovation, research into new materials, and a passion for music, expressed through fine audio engineering. And with products like the Blade, KEF looks set to hold to those goals for years to come.

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