Audiobus is a widely-used iOS library that lets users combine iOS apps into an integrated, modular virtual studio - a bit like virtual audio cables.

Compatible apps build in support for the Audiobus SDK, which allows them to create 'ports' which can either send, receive or process audio.

The Amazing Audio Engine, developed by Michael Tyson, the same developer who created Audiobus, contains a deep integration of Audiobus, with support for:

Receiving Audiobus audio that seamlessly replaces microphone/device audio input.
Sending Audiobus audio from any point in your app: The primary app output, or any channel or channel group.

To integrate Audiobus into your The Amazing Audio Engine-based app, you need to register an account with the Audiobus Developer Center, download the latest Audiobus SDK and follow the instructions in the Audiobus Documentation's integration guide to set up your project with the Audiobus SDK.

Then you can:

Receive Audiobus audio by creating an ABReceiverPort and passing it to The Amazing Audio Engine via AEAudioController's audiobusReceiverPort property.
Send your app's audio output via Audiobus by creating an ABSenderPort and passing it your audio unit.
Send one individual channel via Audiobus by assigning a new ABSenderPort via setAudiobusSenderPort:forChannel:
Send a channel group via Audiobus by assigning a new ABSenderPort via setAudiobusSenderPort:forChannelGroup:
Filter Audiobus audio by creating an ABFilterPort with AEAudioController's audioUnit.

Take a look at the header documentation for the Audiobus functions for details.

We've now covered the basic building blocks of apps using The Amazing Audio Engine, but there's plenty more to know.

Read on to find out about:

Reading from audio files.
Writing to audio files.
Managing audio buffers.
Making your app dramatically more efficient by using vector processing operations.
Efficient, safe and simple inter-thread synchronization using The Amazing Audio Engine's messaging system.
How to schedule events with absolute accuracy.