29 February 2008
The Diamond Anniversary of Stereo
This year is the 75th anniversary of the first stereophonic discs, which were recorded and cut by Alan Blumlein of EMI studios in England in 1933. The recordings were of Blumlein and his fellow engineers talking to each other while walking past a series of stationary microphones. Each microphone was linked to one of two recording channels, depending on its position in the auditorium. These two channels were cut to disc instantaneously, and their combined sound on playback gave the impression of a wide audio field, with disparate signals to left and right.
While Blumlein was not the first engineer to aim for recording in more than one audio channel, he was the most influential. His earlier development of a ‘floating’ disc-cutter (which minimised audio interference from the disc itself by responding directly to the loudness of the sound being played) was both the technological precursor to his own stereo system and the innovation that allowed other engineers to develop theirs. A technical description of stereo and the inventions that led up to its birth can be found here.
As part of our site’s recently added Records & Record Players collection, we present an interview with Blumlein’s son, Simon. In this interview, Simon discusses his father’s work in radio and for EMI, and also his development of the first working radar system and blind navigation bombs during World War II.