| 摘要 |
PURPOSE:To automatically adjust the disorder of frequency characteristics owing to the influence of a sound field by finding the difference between frequency characteristics of a signal obtained by a listening means and frequency characteristics of a souce-side signal and correcting the frequency characteristics according to the difference. CONSTITUTION:The output of a preamplifier 1 is sent to a power amplifier 3 through a graphic equalizer 2 consisting of (n) electronic elements and a voice is generated by a speaker 4 and outputted. The graphic equalizer 2 initially has flat characteristics and an uncorrected voice signal is generated. For the purpose, a microphone 5 is installed at a specific listening point in a sound field formed by the speaker 4 and its signal is supplied to plural band- pass filters 7 through a microphone preamplifier 6. A signal which is divided into (n) audio bands by the band-pass filters 7 is passed through a sample holding circuit 8 and converted by an A/D converter 9 into a digital signal, and a microcomputer 10 controls the timing of sampling. |
