Cooke, an ex-BBC Electrical Engineer, was keen to experiment with new materials and technologies in order to create products with superior acoustic quality that could reproduce recordings as natural as the original performance. From the very beginning, the pioneering inventiveness of KEF loudspeakers was undeniable and now for several decades, audiophiles around the world have revered KEF for its innovative, high-performance loudspeakers.

In the mid 1960s a new bass/midrange unit was under development. For the diaphragm, Cooke and his development team set upon an entirely new material – Bextrene. This was a lightweight acetate plastic sheet derived from wood pulp, subsequently adopted by the BBC for the bass and midrange drivers of the LS5/5 monitor. As well as possessing the required mechanical properties, Bextrene was sufficiently stable to maintain its performance under typical variations in temperature and humidity. Bextrene woofer cones also produced a consistency of sound over a wide bandwidth, qualities which ensured their widespread adoption by other speaker manufacturers in the years that followed.   In 1966, after a period of intensive research and development, KEF launched the a new 5 inch bass/midrange unit (B110), and along with it came a ¾ inch melinex dome tweeter (T27). A larger 8 inch bextrene coned bass unit (B200) followed in 1970. The complete range of KEF drive units allowed great flexibility for the designer and they were subsequently incorporated, in differing combinations, into several million loudspeakers produced by KEF in Maidstone, and around the world by a plethora of other manufacturers. The B110 and T27 were utilised by KEF in the new Cresta bookshelf system and by the BBC in the diminutive but acoustically advanced LS3/5 loudspeaker. This outside broadcast monitor loudspeaker was later refined in 1975 into the LS3/5A – without doubt the most important result of KEF’s collaboration with the BBC. This revolutionary product set the ‘BBC Standard for Loudspeakers’, and has since acquired an almost mythic status among audio-lovers.   The Carlton monitor system was introduced in 1967 - a highly advanced design incorporating a 2.5inch bextrene dome midrange unit, acoustically loaded on its rear surface by a 33 inch damped flexible tube. The three-way Concerto arrived in 1969 bringing high-end performance, in an attractive package, into the mainstream loudspeaker market.   Throughout the mid 1960s, the small but talented design and production engineering team, (including Malcolm Jones - who later went on to form the loudspeaker parts supplier Falcon Acoustics), helped to bring Raymond Cooke’s engineering vision into reality. In 1968 this team was joined by Laurie Fincham, formally chief engineer at Celestion and Goodmans, who was instrumental in the development of KEF’s technical expertise throughout the 1970s and 80s.

This pioneering use of computer-generated data enabled KEF’s engineers to match pairs of speakers to within one half of a decibel, making them the audio-technology equivalent of identical twins. Exact pair matching results in perfect stereo and these revolutionary speaker systems became renowned for their superior acoustic accuracy. Models in the range included the widely celebrated Model 104 – the first domestic unit to match the standards of a broadcast monitor loudspeaker.   Remarkable for its outstanding acoustic precision and wonderfully clean bass performance (despite its relatively small size), the Model 104 'swept reviewers, distributors, retailers and customers off their feet' when it was launched in 1973. As a classic high-output yet high-sensitivity system, the Model 104 was also the first product from KEF's world-famous Reference Series.   Three years later, the design methodology was refined into a new approach to loudspeaker development – computer assisted 'total system design' - with the release of the Corelli, Calinda and Cantata, and a year later, in 1977, came one of the most radical and sophisticated loudspeakers ever made – Reference Model 105. With separate enclosures for the bass and mid/high sections to allow time-alignment and even sound dispersion over the entire audio range, fourth order Linkwitz-Riley acoustic crossovers and a striking form following its acoustic function, it set new standards for domestic loudspeakers.

Throughout the 1980s, KEF maintained its reputation for excellence with the now highly respected Reference Series through a series of technical enhancements. These included: Coupled-Cavity bass loading that considerably boosted bass performance; force-cancelling and driver decoupling to eliminate cabinet colouration from the mechanical vibrations of the drive unit chassis; conjugate load matching to ease the electrical load presented to the amplifier and the KEF Universal Bass Equaliser (KUBE) that allowed extended bass from compact enclosures. Incorporating all these features was the Reference 104/2 released in 1984 of which substantial numbers were sold around the world.   In 1985 a range of car audio products was released including a subwoofer using the coupled cavity system developed in the 104/2, and 1987 saw the introduction of the Custom Series of in-wall products, harking back to the K1 and K2 baffles of the 1960s and heralding a new era of application-focussed ingenuity in this expanding market.   In 1988, incorporating a new neodymium/iron/boron magnetic material, developed by NASA, with ten times the power of standard speaker magnets, the revolutionary KEF Uni-Q was born. This major innovation allowed KEF engineers to make a tweeter small enough to be mounted at the acoustic heart of the bass unit coil, providing for the first time a single point source of sound. In layman's terms, this considerably enlarged the optimum listening area in any room. Searching for that elusive acoustic 'sweet spot' was now a thing of the past and Uni-Q remains a key KEF differentiator today.

KEF's visionary founder, Raymond Cooke, sadly passed away in 1995. However, he left the company with firm guiding principles encapsulated in his core values of 'Quality, Honesty, Dedication and Innovation'. That same year the Reference Series Model Four, with its fourth-generation Uni-Q drive unit it attracted worldwide acclaim and numerous plaudits from the industry press. Stereophile magazine's chief reviewer noted that it was 'the best I've had in my listening room', while Hi-Fi News dubbed it 'KEF's best yet'. Two years later, the next generation Q Series and the new Monitor Series were introduced – both outstanding testaments to Cooke’s legacy.   As the home theatre market developed through the late 1990s KEF's engineers set to work on the next generation of affordable, high performance subwoofer/satellite systems. The result was the KHT2005 system released in 2001, featuring the iconic 'egg' shaped satellite. The high quality feel of the cast aluminium enclosure, coupled with the superior acoustic performance of Uni-Q, set new standards in its class and it dominated this ultra competitive market for several years.

In 2005, KEF revealed to the world what had been a closely guarded secret since the late 1980s – ACE technology. After a comprehensive research and development program, the KHT9000 system showed how putting activated carbon inside a loudspeaker enclosure vastly increases its effective internal volume - allowing enhanced bass extension from compact cabinets. Finally, the loudspeaker industry had a means of circumventing the age-old constraint that extended bass requires a large enclosure. What’s more – the bass quality of an ACE loaded closed box enclosure is as good as it gets – with a unique combination of extension and superior transient response.   ACE also plays an important role with one of the latest and possible the most remarkable KEF loudspeaker to date – Muon. A collaboration with leading British designer Ross Lovegrove, Muon was revealed to the world at the Milan Furniture Fair in April 2007 as a triumph of form marrying function and contains the latest technological acoustic breakthroughs from the KEF engineering team.   Now under in its 5th decade, KEF is still developing world-beating products. Scientific innovation and hands-on experimentation continue to underwrite its reputation as the audiophile’s ultimate loudspeaker manufacturer.