Stage-expanded stereophonic sound reproduction

Abstract

A stereophonic reproduction system comprises a localization network receptive of sterophonic signals to localize of sonic images at desired locations. A crosstalk canceler, connected in tandem with the localization network, cancels acoustic crosstalk interference. The localization network comprises in each channel a first adder providing algebraic summation of the input signal of the own channel and a negative feedback signal supplied from its output through a first subtractor and through a first transfer circuit having a transfer function representing the ratio of hypothetical crosstalk path transfer function to hypothetical direct path transfer function. The subtractor also responds to the signal of the other channel to algebraically combine the received signal in phase through the first transfer circuit with the input signal of the own channel. The crosstalk canceler comprises in each channel a second adder providing algebraic summation of the signal from the first adder and the signal of the same channel through a second subtractor and a second transfer circuit having a transfer function representing the ratio of actual crosstalk path transfer function to actual direct path transfer function. The second subtractor also responds to the signal from the second adder of the other channel to combine the received signal with the signal from the first adder in opposite phase through the second transfer circuit. Attenuators permit manual adjustment of signals supplied to the first and second subtractors of each channel.