---
title: vDSP.Biquad
framework: accelerate
role: symbol
role_heading: Structure
path: accelerate/vdsp/biquad
---

# vDSP.Biquad

A single- or double-precision biquadratic filter.

## Declaration

```swift
struct Biquad<T> where T : vDSP_FloatingPointBiquadFilterable
```

## Overview

Overview note: The vDSP biquadratic filters work in place. That is, the source and destination pointers may point to the same memory.

## Topics

### Initializers

- [init(coefficients:channelCount:sectionCount:ofType:)](accelerate/vdsp/biquad/init(coefficients:channelcount:sectioncount:oftype:).md)

### Instance methods

- [apply(input:)](accelerate/vdsp/biquad/apply(input:).md)
- [apply(input:output:)](accelerate/vdsp/biquad/apply(input:output:).md)

## See Also

### Biquadratic IIR Filters

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