The Equivalence of Various Methods of Computing Biquad Coefficients for Audio Parametric Equalizers
Robert Bristow-Johnson · 1994
Several authors have put forth design procedures for obtaining the coefficient values for second order digital filters to be used as parametric equalizers or "presence" filters. Given the EQ parameters, these differing design methods, having greatly disparate degrees of complexity, compute the filter coefficients. This paper shows that, with the possible exception of Q or bandwidth definition, all methods must be equivalent and the simplest method may be used. A method of computation is presented here in which the bandwidth is specified in octaves. 0