Improvements in or relating to filters

摘要

The application discloses a new digital IIR filter structure which uses at least one fewer multiplier than presently available in current digital IIR filter structures. In particular, by constraining one or both endpoint values (0 and fs/2) to unity, the disclosed approach uses 2 multiply operations instead of 3 for first-order structures and 3 multiply operations instead of 4 or 5 for second-order structures. This multiplier reduction enhances the capacity of the current audio equalizer digital signal processor by 30%.