Equalizer with adjustable band filters and a digital filter suitable for use in the equalizer

摘要

A manually operated or automatic equalizer (1) with adjustable band filters for varying the frequency characteristic of an electric signal presented to an input (2) and for applying a frequency characteristic-adapted electric signal to an output (3). The equalizer has a plurality of band filters (F1 to Fn) with their bands located adjacent to one another in a given frequency range. The distance (frequency separation) between the central frequencies of filters having neighboring bands is greater than the distance between the central frequencies of one third octave filters having neighboring bands located at at least approximately the same frequencies as those of the band filters (Fi). At least those band filters (F1 to Fm) whose bands are located in the low-frequency part (f<450 Hz) of the frequency range have a central frequency (fci) which is variable. A digital filter which can be used as a band filter in the equalizer is also described.