A "desktop theater" based on personal computers

The circuit of the surround sound processor is shown in Figure 10-l. The operating voltage of the circuit is 12V, and the control part uses sv voltage. The sound
effect mode is controlled by the high and low levels of pin ⑦ and pin @ of PC1892. The four functions are shown in Table lo-l.
    When the ⑦ pin is connected to the ground, the @ pin is connected to the V voltage , which is used to have an immersive feeling when enjoying VCD movie discs. RP] is the music
effect control, RP2 is the output balance control, and RP3 is the front left and right channels. Volume control, RP4 is the rear surround sound volume
control, RP5 is the bass control, and RP6 is the treble control. The whole circuit is simple and easy to make. The circuit board can be designed by yourself.
    The surround sound processor can be connected to the line output of the movie card or sound channel card. The front output is connected to the active speaker. The rear speaker
can installed on the back of the seat or the furniture behind it. Adjusting the volume appropriately can achieve great results.