LINEAR-PHASE FIR AUDIO FILTER, PRODUCTION METHOD AND SIGNAL PROCESSOR

摘要

The invention relates to a method for producing a linear-phase digital FIR filter (4) from two sub-filters (6a, b) for an audio signal (AU, AF), in which method the sub-filters (6a, b) are provided as sub-sets (Ta, b) having numbers (Ma, b) of coefficients, a lower cutoff frequency (Ga, b) of the particular sub-filter (6a, b) being greater than the sampling frequency of the audio signal (AU, AF) divided by the number (Ma, b), the sub-sets (Ta, b) are linearly convoluted with one another so as to form a total set (SU) having a number (L) of coefficients greater than the numbers (Ma, b), and the total set (SU) is symmetrically reduced to a number (Z) less than the number (L), so as to form a reduced total set (SK) of the filter (4). A linear-phase digital FIR filter (4) for an audio signal (AU, AF) is created by the method. A signal processor (2) for an audio signal (AU, AF) contains the filter (4).