| 摘要 |
PURPOSE:To obtain a digital graphic equalizer with less ripple at a flat region by changing the filter coefficient according to the designation of a characteristic input section, adding coefficients by bands to obtain a new coefficient, changing the frequency characteristic by using it and attenuating the designated band when an input level exceeds a prescribed value. CONSTITUTION:A coefficient of a filter at a band corresponding to the designation from the characteristic input section 15 among plural coefficients (1-l) of FIR digital band filters 191-19n assumed by plural bands is changed according to the designation, coefficients of plural bands (1-n) are added to plural coefficients (1-l) to obtain coefficients h1-hl the same number as the number (l) of plural coefficients. When the coefficient of the band subject to emphasis designation is changed again in the attenuating direction when the input signal level exceeds a prescribed value and the frequency characteristic of the FIR digital filter 50 is changed based on the obtained coefficient. |
