Hiroshi Kowaki

Apparatus for expanding and controlling sound fields

As in a compartment of an automotive vehicle, when a left- and a right-channel loudspeakers are disposed at angularly different positions from each other with respect to a frontward direction of a listening position, there will be formed a sound field laterally asymmetric with respect to the frontward direction of the listening position. In order to correct the asymmetry of the sound field, a crosstalk signal obtained by correcting the phase and the level of an acoustic signal of the left-channel from an acoustic signal source and a crosstalk adjustment signal obtained by correcting the level of the acoustic signal of the left-channel are fed to the right loudspeaker, or a center loudspeaker disposed between the left and right loudspeakers, together with an acoustic signal of the right-channel from the acoustic signal source. Similarly, a crosstalk signal obtained by correcting the phase and the level of an acoustic signal of the right-channel and a crosstalk adjustment signal obtained by correcting the level of the acoustic signal of the right-channel are fed to the left or center loudspeaker together with the acoustic signal of the left-channel from the acoustic signal source.