Patent ID: 7058126

Claim:
A graphametric equalizer comprising: a plurality of equalizing filters spanning a predetermined audio bandwidth; a data processor; a data input device in communication with the data processor; a translation function algorithmic software directing the data processor; a softening function algorithmic software directing the data processor; and a data storage unit, wherein discrete center frequency data, discrete bandwidth data and discrete gain data is stored and supplied to the data processor such that the data processor, directed by the translation function algorithmic software, can determine filter parameters using algorithmically defined relationships among the discrete center frequency data, discrete bandwidth data and discrete gain data such that the plurality of equalizing filters can be recharacterized by the filter parameters, and further wherein discrete timing data and discrete incrementing data is stored and supplied to the data processor such that the data processor, directed by the softening function algorithmic software, can determine gain incrementing parameters and timing parameters such that the plurality of equalizing filters can be recharacterized; wherein each equalizing filter comprises an allpass filter having a multiplier dependent upon a predetermined bandwidth and a predetermined peak gain for a cut region below 0 dB and further dependent solely upon a predetermined bandwidth for a boost region above 0 dB; and wherein the translation function algorithmic software is configured to approximate the allpass filter multiplier in the cut region below 0 dB and comprises the multiplier approximation function: β≈tan(π BW/F 8 )/log 2 (3)· k ; wherein β is the allpass filter multiplier, BW is a user selected allpass filter bandwidth, Fs is a user selected sampling frequency, and k is a user selected peak gain of the equalizing filter.