---
title: Biquadratic IIR filters
framework: accelerate
role: collectionGroup
role_heading: API Collection
path: accelerate/biquadratic-iir-filters
---

# Biquadratic IIR filters

Apply biquadratic filters to single-channel and multichannel data.

## Topics

### Biquadratic IIR Filters

- [Equalizing audio with discrete cosine transforms (DCTs)](accelerate/equalizing-audio-with-discrete-cosine-transforms-dcts.md)
- [vDSP.Biquad](accelerate/vdsp/biquad.md)

## See Also

### Audio Processing

- [Visualizing sound as an audio spectrogram](accelerate/visualizing-sound-as-an-audio-spectrogram.md)
- [Applying biquadratic filters to a music loop](accelerate/applying-biquadratic-filters-to-a-music-loop.md)
- [Equalizing audio with discrete cosine transforms (DCTs)](accelerate/equalizing-audio-with-discrete-cosine-transforms-dcts.md)
- [Discrete Cosine transforms](accelerate/discrete-cosine-transforms.md)