Sidney George Brown, the company founder, was a prolific inventor of electromechanical devices, including the "Microphone Amplifier" (1921) which permitted loudspeaker operation from a crystal set without the use of valves, and a gyro compass. He set up a business in Watford (North of London) in the year 1910 and later had a works in North Acton, London W3. The company eventually became part of the Racal organisation which in turn became part of Thales-Racal Acoustics.