The present invention relates broadly to a method of digitally filtering an audio signal at a predetermined sample rate by applying a composite audio filter derived at an increase sample rate. The composite audio filter is obtained by combining one audio filter with another audio filter at the increased sample rate. The sample rate of the audio filters may be increased from their predetermined to the increased sample rate using various weighting techniques. The composite filter may provide a frequency response curve with a corner frequency as it approaches the Nyquist frequency whereas the frequency response of a conventional filter (shown in broken line detail) is flat with no effect.