4-Channel surround sound generator

DETAILED DESCRIPTION It is, therefore, an object of the invention to provide a four-channel surround-sound generator capable of generating a first surround-sound in phase to a basic channel reproduction sound and a second surround-sound out of phase thereto, by employing a channel-switching control circuit and a channel-sound delaying circuit.
According to one aspect of the present invention, the four-channel surround-sound generator having a first-channel sound reproduction means and a second-channel sound reproduction means, each reproducing a respective channel-sound through a speaker, comprises: a third-channel amplifier and a fourth-channel amplifier, respectively, receiving the first-channel and second-channel sounds for amplifying said each received sound to a signal level adequate to a first surround speaker and a second surround speaker, respectively; surround mode selection means, receiving the first-channel sound and the second-channel sound from said each reproduction means, and in response to inputting of a first mode selection control signal, enabling or disabling to filter said received first-channel and second-channel sounds with a given bandwidth; surround-sound output control means, coupled between said surround mode selection means and said third-channel and fourth-channel amplifiers, for selectively enabling or disabling to make delay of the filtered first-channel and second-channel sounds supplied from the surround mode selection means, in response to inputting of a second mode selection control signal, upon delivering to said third-channel and fourth-channel amplifiers said filtered first-channel and second-channel sounds; and means for buffering control signals applied from a microcomputer, to provide said surround mode selection means with said first mode selection control signal and/or said surround-sound output control means with said second mode selection control signal.