KEF is a British loudspeaker manufacturer with international distribution. It was founded in Tovil, Maidstone, Kent in 1961 by electrical engineer Raymond Cooke and named after Kent Engineering & Foundry with which it originally shared the site. Its founder, Raymond Cooke, was created OBE by Elizabeth II in 1979.

Raymond Cooke and Robert Pearch founded KEF Electronics Ltd., with a view to creating innovative loudspeakers using the latest in materials technology. KEF Electronics was founded in Kent in 1961 and was physically situated on land adjacent to the River Medway in Tovil which at the time was owned by Kent Engineering & Foundry (a company owned by Robert Pearch and founded by his father Leonard) who at the time manufactured agricultural equipment and industrial sweeping machines. KEF derived its name from the firm

Cooke was a Royal Navy WWII veteran who was a design engineer at the British Broadcasting Corporation (BBC) for a year. He was later Technical Director at Wharfedale, then a leading British loudspeaker manufacturer. Following corporate change at Wharfedale, Cooke left to see his own ideas put into action.[1] Cooke acquired the site of a foundry, makers of agricultural machines, and initially worked in Nissen huts erected on the site in Tovil, Maidstone. In KEF: 50 Years of Innovation in Sound, the authors assert that KEF reduced the average size of bass-rich home loudspeakers from 9–10 cubic feet (250–280 l) to about 2 cubic feet (57 l), based on the work on the “acoustic-suspension woofer” at Acoustic Research; the company pioneered large-scale production of drivers with cones made of materials other than paper, and the application of fast Fourier transform analysis to the measuring of loudspeakers. KEF was also an early-adopter of modern quality-control principles to driver manufacture.

The first loudspeaker manufactured was the K1 Slimline for which the drive units used diaphragms made of polystyrene and melinex. Soon after, in 1962, came the famous B139 ‘racetrack’ shaped woofer which allowed the design of the Celeste – one of the first truly high performance bookshelf loudspeakers. As Laurie Fincham, Cooke’s successor as chief engineer, later revealed, the only reason the B139 was vertically mounted ovoid-shaped was that the British tax code at the time penalised 2 way speakers below a certain arbitrary width. Professional products were not taxed and professional was defined as above 8 inches for a woofer or as a 3 way speaker.