---
title: AUAudioUnitV2Bridge
framework: audiotoolbox
role: symbol
role_heading: Class
path: audiotoolbox/auaudiounitv2bridge
---

# AUAudioUnitV2Bridge

A class that wraps a version 2 audio unit as version 3 audio unit.

## Declaration

```swift
class AUAudioUnitV2Bridge
```

## Overview

Overview A version 3 audio unit may subclass the AUAudioUnitV2Bridge class. If so, the audio unit’s component description should refer to a registered component with a version 2 implementation by using a factory function. The bridge will instantiate the version 2 audio unit via the factory function and communicate with it using version 2 audio unit APIs. Hosts should not access this class; it will be instantiated if needed when creating an audio unit.

## Topics

### Instance Properties

- [audioUnit](audiotoolbox/auaudiounitv2bridge/audiounit.md)

## Relationships

### Inherits From

- [AUAudioUnit](audiotoolbox/auaudiounit.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### Audio Units

- [Creating an audio unit extension](avfaudio/creating-an-audio-unit-extension.md)
- [Creating custom audio effects](avfaudio/creating-custom-audio-effects.md)
- [Incorporating Audio Effects and Instruments](audiotoolbox/incorporating-audio-effects-and-instruments.md)
- [Debugging Out-of-Process Audio Units on Apple Silicon](audiotoolbox/debugging-out-of-process-audio-units-on-apple-silicon.md)
- [Rendering Spatial Audio from Bluetooth headphones](audiotoolbox/rendering-spatial-audio-from-bluetooth-headphones.md)
- [AUAudioUnit](audiotoolbox/auaudiounit.md)
- [AUAudioUnitBus](audiotoolbox/auaudiounitbus.md)
- [AUAudioUnitBusArray](audiotoolbox/auaudiounitbusarray.md)
- [AUAudioUnitPreset](audiotoolbox/auaudiounitpreset.md)
- [AUHeadTrackingBinauralRenderer](audiotoolbox/auheadtrackingbinauralrenderer.md)
- [AudioUnitExtensionCopyComponentList(_:)](audiotoolbox/audiounitextensioncopycomponentlist(_:).md)
- [AudioUnitExtensionSetComponentList(_:_:)](audiotoolbox/audiounitextensionsetcomponentlist(_:_:).md)
- [AUAudioUnitFactory](audiotoolbox/auaudiounitfactory.md)