Introduced in last year’s Mac OS X El Capitan release, Inter-Device audio allows iOS 9 devices to output digital audio directly into a Mac computer via the Lightning cable. The reason the protocol hasn’t received proper attention is, the settings are buried in OS X’s labyrinth of System Preferences. Fortunately, Matthias Frick has come to the rescue with his free open-source app, iOXAudio, which installs a handy set of controls right on your menu bar for turning it on/off.
With Inter-Device audio enabled via the app, all you have to do is open up your preferred Mac-based DAW and select your iPhone or iPad from the input pull-down menu in your preferences. From there, any audio in your mobile device will be available for recording in your DAW.
Granted, latency is a significant issue with this protocol. When using Ableton Live with extremely small buffer settings, I still had to nudge my tracks anywhere from 50-125 milliseconds for synchronized apps (using Ableton Link, naturally) to line up. To be clear, this is an issue with Inter-Device audio and not Link.
However, if you’re doing iOS sound design with apps such as Boulanger Labs’ extraordinary csSpectral (boulangerlabs.com), this is the slickest way to get the results into your DAW. Best of all, it’s free. Download iOXAudio from https://github.com/sieren/ioxaudio/releases.