Quad Electroacoustics, originally the Acoustical Manufacturing Company Ltd., was founded by Peter J. Walker in 1936 in London, with the name 'QUAD' being an acronym for 'Quality Unit Amplifier Domestic.' The company relocated to Huntingdon in 1941 after being bombed during WWII and revolutionized audio with the 1957 Quad Electrostatic Loudspeaker (ESL), the first production full-range electrostatic speaker. Quad's motto 'The Closest Approach to the Original Sound' reflects their commitment to sonic transparency. In 1997, Quad joined the International Audio Group (IAG) based in Shenzhen, China, though R&D and service operations remain in Huntingdon, England. Under IAG ownership, Quad continues producing their renowned ESL electrostatic speakers (current ESL 2812/2912 models), plus integrated amplifiers, wireless streamers, CD players, passive speakers, preamplifiers, power amplifiers, and headphones through their Artera, VENA, and Revela series.