AES Section Meeting Reports

Indiana University - February 6, 2017

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Peter Scheiber presented his captivating history with surround sound.
The original design and build of the four-channel matrix encoder/logic decoder was developed by Peter Scheiber during his graduate studies at the Indiana University School of Music in 1967. The combination encoder/logic decoder was designed around op amps and analog multipliers, which was later made of discrete transistors on plug-in circuit boards in 1968. Because the op amps depended on gains in the tens of thousands, stability, particularly about ground and supply impedances, was a concern; copper strips were used for ground and power busses.
With four speakers in the corners of the room, Peter Scheiber's work reproduced high-fidelity quadrophonic sound that demonstrated market-viable surround technology. Peter Scheiber eventually built a cancellation SQ decoder, called the 360º Spatial Decoder, whose logic speed was continuously variable, responding to program envelope slope. The logic ran fastest in response to high envelope slope, signifying an attack, and slowest for zero or negative slope, signifying a steady-state or decaying sound. Peter Scheiber's journey with his surround sound technology continued till the 1990's, but in 1983, he had to settle a patent infringement suit with Ray Dolby and Dolby Labs on the use of the surround system, dealing with patent royalties from 1994-2003 and the developed usage of the system till the present day.

This summary only skims through a small percentage of the valuable history with Peter Scheiber's surround technology. For more information, please contact
Thank you to the Central Indiana AES Section for the help with organizing this event!

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AES - Audio Engineering Society