Alan Blumlein and the invention of Stereo

by EMI Archive Trust

Alan Blumlein was a senior sound engineer at EMI’s Central Research Laboratories (CRL) on the Hayes factory site. He joined the company when Columbia and The Gramophone Company merged in 1931. Over his lifetime he was a prolific inventor, developing huge technological advances within the sound engineering field.

After a night at the cinema with his wife, Blumlein was frustrated that the sound from a character on screen could only be heard from a speaker on the corresponding side of the room.  To solve this problem, Blumlein began working on a binaural (now known as stereo) system which is still in use today.

He started by abolishing the idea that two loudspeakers represented the listeners’ two ears and instead sought to re-create the features of the sound field including directional information. He then set about developing a complex cut on the gramophone record with two grooves that could be read simultaneously to playback the new stereo (Binaural) sound yet still remain compatible with the existing mono records.

Instead of using the complex mathematics and physics of his new concept, to explain this new technology to the directors and business team at EMI, Blumlein created a large scale model. It showed how one needle in a specially cut groove on a record could give out two signals simultaneously resulting in a more stereophonic sound.

Alan Blumlein Stereo Model from EMI Archive Trust on Vimeo.

On the 14th of December 1933 the first wax disc was cut in a test recording of stereo sound for the first time at the auditorium of the EMI site in Hayes. This “Walking and Talking” film is one of the stereo tests that were carried out in subsequent days to demonstrate the new technology.

Although this recording was taken in 1933 Blumlein applied for the patent of what he called ‘binaural’ sound (stereo sound) in a paper which patented stereo records as well as stereo films and surround sound in 1931. Much of the technology pioneered by Blumlein and his team is still in use at Abbey Road Studio’s and in many other studio’s all over the world today.

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