AUDIO SIGNAL PROCESSING CIRCUIT AND ITS METHOD

摘要

PROBLEM TO BE SOLVED: To obtain a highly accurate shuffler type filter by simple constitution by setting up the accuracy in a low frequency area of a 2nd filter higher than that of a 1st filter. SOLUTION: The left channel signal and the right channel signal are mutually added by an adder 22 and the added signal is applied to the 1st filter 20a. The right and left channel signals are mutually subtracted by a subtractor 24 and the subtracted signal is applied to a 2nd filter 20b. Each of the 1st and 2nd filters 20a, 20b is constituted of an FIR type filter. The number of taps (namely the number of delay processing elements) of the 1st filter 20a is set up to '32' e.g. and the number of taps of the 2nd filter 20b is set up to '96' e.g. In the FIR type filter the accuracy in a low frequency area is increased in proportion to the increment of the number of taps. Thereby the accuracy in the low frequency area in the 2nd filter 20a is higher than that of the 1st filter 20a.