---
title: vDSP_biquad2_CreateSetup
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.9+]
path: kernel/1532224-vdsp_biquad2_createsetup
---

# vDSP_biquad2_CreateSetup

Builds a data structure that contains precalculated single-precision data for stereo biquadratic filter functions to use.

## Declaration

```occ
vDSP_biquad_Setup vDSP_biquad2_CreateSetup(const double *, const size_t, const IIRChannel);
```

## Parameters

- `Parameter 0`: A pointer to the double-precision filter coefficients.
- `Parameter 1`: The number of sections in the biquadratic filter.
- `Parameter 2`: An enumeration that specifies the channel.

## Discussion

Discussion If the channel parameter is vDSP_IIRMonoLeft or vDSP_IIRMonoRight, the number of elements in the coefficients array must be five times the number of sections. The filter applies pass-through coefficients to the other channel. If the channel parameter is vDSP_IIRStereo, the number of elements in the coefficients array must be ten times the number of sections. Specify five left-channel coefficients followed by five right-channel coefficients.

## See Also

### Biquadratic Infinite Impulse Response (IIR) Filters

- [vDSP_biquad2](kernel/1532195-vdsp_biquad2.md)
- [IIRChannel](kernel/iirchannel.md)
- [vDSP_biquad2_CopyState](kernel/1532220-vdsp_biquad2_copystate.md)
- [vDSP_biquad2_ResetState](kernel/1532215-vdsp_biquad2_resetstate.md)
- [vDSP_biquad2_DestroySetup](kernel/1532201-vdsp_biquad2_destroysetup.md)