Opens in a new tab

AES E-Library

← Back to search

Journal Article

Analytical Design of Biquadratic Filter Sections for Parametric Filters

Authors: Shpak, Dale J.

Journal of the Audio Engineering Society · Volume 40 · Issue 11 · pp. 876–885 · November 1992

Abstract

Quadratic and biquadratic filter sections are often used in audio applications since only moderate filter selectivities are usually required. When a number of filter sections are cascaded, it can be advantageous to use filters with a nominal stopband gain of unit. The passband of each filter can then be varied about the 0-dB level, thereby realizing a filtering system capable of boosting or attenuating an input signal within multiple frequency bands. New closed-form expressions for analog biquadratic bandpass filters meeting prescribed specifications are first derived. This is followed by a method for transforming conventional analog filters. These results are then extended to the discrete-time domain through the use of the bilinear transformation. A distinct advantage of the proposed method is that since closed-form methods are used, the coefficients of a parametric filter can be readily recomputed in real time in response to a user specifying any of a new center of frequency, bandwidth, or peak gain. Examples of digital filter designs are given in the context of audio-frequency filtering.

Details

Publication
Journal of the Audio Engineering Society
Volume
40
Issue
11
Pages
876–885
Publication date
November 6, 1992
Affiliation
Department of Engineering, Royal Roads Military College, FMO, Victoria, B.C., Canada (See document for exact affiliation information.)
Type
Journal Article