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Project #1 - From Stereo to Ambisonics
Blumlein to Gerzon 1903 to 1996 The Subject |
Alan Blumlein developed a process to record sounds in a two
channel format in 1931, one that was compatible with the monophonic
playback of his time and beyond. It was 1941 before
multi-channel sound was used in the Disney film Fantasia,
but 1975 before Dolby stereo became a standard for multi-channel
reproduction in film. Stereo records in the home came around
the late 1950s.
Michael Gerzon modified Blumlein's binaural microphone system. Instead of using a Blumlein pair of two crossed figure-8 microphones, he used 4 cardioid microphones, each placed on a face of a tetrahedral. (For a view of my experimental tetrahedral microphone, see Soundscapes.) Not only would Gerzon's device record surround in a horizontal plane, the tetrahedral also would record the vertical component of the soundfield. By recording four channels of audio, Gerzon concluded, mathematically one can derive mono, stereo, and any number of output channels for playback. The microphone Gerzon and Peter Craven invented is indeed called a Soundfield™ microphone, introduced commercially by Calrec in 1978. |
One minute portion of the project. I am talking about Alan Blumlein in 1931. |
Michael Gerzon continued the work of his fellow countryman Alan Blumlein.
Mathematicians and audio enthusiasts throughout the world continue to study
their contributions to audio and psychoacoustics.
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