DescriptionIEEE Milestone Plaque - Alan Dower Blumlein.jpg
English: IEEE Milestone plaque awarded posthumously to Alan Dower Blumlein in 2015 for the invention of Stereo. This plaque is mounted by the front door of Abbey Road Studios
IEEE MILESTONE IN ELECTRICAL ENGINEERING AND COMPUTING Invention of Stereo Sound Reproduction, 1931Alan Dower Blumlein filed a patent for a two-channel audio systemcalled “stereo” on 14 December 1931. It included a “shuffling”circuit to preserve directional sound, an orthogonal “BlumleinPair” of velocity microphones, the recording of two orthogonalchannels in a single groove, stereo disc-cutting head, and hybridtransformer to mix directional signals. Blumlein brought hisequipment to Abbey Road Studios in 1934 and recorded the LondonPhilharmonic Orchestra.April 2015IEEE
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