title: How can I programmatically create a multi-output device in OS X?
body: <p>How can I programmatically create a Multi-Output Device in Mac OS X?</p>
  
  <p>The Audio Midi Setup program provides a GUI interface for creating one, but I would like to be able to create one in code.</p>
  
  <p>I've found some resources already for creating aggregate devices, but multi-output devices function differently and I can't find anything on creating them. Here's what I've got so far:</p>
  
  <ul>
  <li><a href="https://support.apple.com/en-us/HT202000" rel="noreferrer">How to combine multiple audio interfaces by creating an aggregate device</a></li>
  <li><a href="https://developer.apple.com/library/mac/documentation/MusicAudio/Conceptual/CoreAudioOverview/ARoadmaptoCommonTasks/ARoadmaptoCommonTasks.html#//apple_ref/doc/uid/TP40003577-CH6-SW12" rel="noreferrer">Using Aggregate Devices</a></li>
  <li><a href="http://daveaddey.com/?p=51" rel="noreferrer">Creating Core Audio aggregate devices programmatically</a></li>
  <li><a href="https://apple.stackexchange.com/questions/84173/what-is-the-difference-between-an-aggregate-and-a-multi-output-device">What is the difference between an “aggregate” and a “multi-output” device?</a></li>
  </ul>