This page contains software naterial for the paper

Balázs Bank, "Perceptually Motivated Audio Equalization Using Fixed-Pole Parallel Second-Order Filters", IEEE Signal Processing Letters, to be published in 2008. URL: http://www.acoustics.hut.fi/go/spl08-parfilt## Abstract

In audio, equalizer design should take into account the frequency resolution of the auditory system. In this paper, this is accomplished by the fixed-pole design of parallel secondorder filters. The design process has two steps: first, the poles of the filter are set according to the desired frequency resolution. Then, the feedforward coefficients of the second-order filters are determined by a linear least squares solution. The proposed parallel filter achieves effectively the same equalization results as the Kautz filter, but requires 33% fewer multiplications and additions.

## MATLAB functions

Here you can find some Matlab functions for designing the parallel second-order filters. They are all included in the file parfilt.zip. See the help part of the functions for details, or check the roomcomp script for understanding how to use them.

The files included in the zip file are the following:

- roomcomp - Filter design example for loudspeaker-room response compensation
- parfilt - Filtering operation using the parallel filter structure
- parfiltid - LS identification of the parallel second-order filter from input and output
- parfiltdes - LS design of the parallel second-order filter, difference from parfiltid is that the input is assumed to be a unit pulse
- tfplot - Logarithmic 1/100 octave resolution transfer-function plot for displaying the results
- tfplots - Thrid-octave smoothed transfer-function plot
- roomresp.mat - The measured loudspeaker-room impulse response
To see how to use the parallel filter with warped pole positioning, check out the companion page of my ICMC07 paper.

URL:http://www.acoustics.hut.fi/go/spl08-parfilt

Last modified:07.03.2008.

Author:<bbank@acoustics.hut.fi>