Quadrophonic Matrix Encoder

The technology developed and used in the 1970`s applies an encoding Matrix to the four input channels LF (Left Front), RF, LB (Left Back) and RB to record them into 2 channels. Playing back such an encoded recording by applying the correct decoding matrix brings back most of the original four channels (4:2:4 Encoding/Decoding). Technical Specification:- The 90 degree phase shift (Hilbert Transformation) to complexify the input signals has been implemented in the time domain by using IIR-All-Pass filters with a Precision better than 1 degree. - For the listed matrixes the imaginary signal term j is defined as leading phase shift of 90 degrees- Sampling Frequency: 44.1 kHz- Sampling Resolution: 16Bit- Digital Signal Processing in 64Bit floating point precision