Coefficient calculation schemes for discrete-time audio equalizers are examined. Close attention is paid to minimizing filter response distortion and the computational load for on-line calculation. Offset and image distortion correction schemes are developed to improve the matched z response distortion. It is shown that prewarping the peak gain in the matched z results in a relatively affordable increase in computation and improves the response, stability, and noise characteristics of the resulting filters. The effects of the emerging higher sampling rates and their influence on coefficient transforms are also explored.
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