| 摘要 |
PROBLEM TO BE SOLVED: To conduct effectively sound reproduction by summing left/right channel signals, deciding an average level with an output signal of other adder, deciding a quotient with a divider after smoothing and conducting fader control with a prescribed coefficient. SOLUTION: Audio signals LV, RV are fed to an adder 12.1 and outputs are led to any of adders 12.2, 12.3. Composite signals Sum 1-3 formed therein are obtained. The signals Sum 1-3 are given to a device 13, in which digital processing of an audio signal is conducted. Then an HPF 15 is provided to each A/D converter 14 to exclude a DC voltage. After the signals Sum 1-3 pass through the HPF 15, divided into three parallel channels and a device 17 deciding a mean level decides the mean level and smoothed (18). The smoothed signals Sum1', Sum4' are fed to a threshold level device 19, and a quotient Q is decided by a divider 20 placed at a succeeding stage and fed to a computer 21. Fader control is conducted at a fader control section 11 by using coefficients FV, FH obtained by the computer 21 to reproduce sound. |
