| 摘要 |
PURPOSE:To obtain a desired band emphasis and attenuation characteristic without deviation by addition and less ripple at a flat region in obtaining a summing overall characteristic by using a specific FIR digital filter. CONSTITUTION:A controller 9 sets a coefficient data corresponding to plural coefficients of a digital filter corresponding to the designation from a characteristic input section 13. Then in a DSP 4, outputs of plural FIR digital band-pass filters 171-17n connected in parallel while being constituted to obtain a characteristic being convex or/and concave in positive or/and negative directions with respect to a reference level in common to each band are added by an adder section 19, and the frequency characteristic of the plural FIR digital band-pass filters 171-17n based on the coefficient data obtained by the control means is changed. Thus, a natural tone color with less ripple at the flat region is obtained and the accurate synthesis characteristic is obtained without causing shift by addition in obtaining the summed overall characteristic of each band- pass filter. |
