Biquadratic IIR filters Apply biquadratic filters to single-channel and multichannel data. TopicsBiquadratic IIR FiltersEqualizing audio with discrete cosine transforms (DCTs)vDSP.Biquad See AlsoAudio ProcessingVisualizing sound as an audio spectrogramApplying biquadratic filters to a music loopEqualizing audio with discrete cosine transforms (DCTs)Discrete Cosine transforms