VARIABLE MATRIX DECODER FOR USE IN 4-2-4 MATRIX PLAYBACK SYSTEM

摘要

A decoder for use in a four channel playback system includes a control unit and a variable matrix. The control unit produces first and second control outputs which vary in opposite directions in accordance with the phase relationship between two channel signals. The variable matrix includes a first variable matrix circuit for producing two outputs related to the front channels and having matrix coefficients controlled by the first control output from the control unit and a second variable matrix circuit for producing two outputs related to the rear channels and having matrix coefficients controlled by the second control output from the control unit. The control outputs are used to improve the separation between front channels and to degrade the separation between rear channels, and vice versa, thereby enhancing the sense of presence of listeners in a reproduced sound field. The present invention discloses another decoder which comprises a first control unit for front-rear control and a second control unit for left-right control whereby front-left and right channels and rear-left and right channels are independently controlled.