For AudioBox 1818VSL users that wish to use the 24/96 SMUX functionality, you'll need to select 14ch-32bit Float in the drop down next to the Sample Rate selection.
Step 1: Open up your Application Folder and then open up the Utilities Folder
Step 2: Once in the Utilities folder, run the "Audio MIDI Setup" Utility (icon looks like a single octave keyboard).
Step 3: You'll need to select your AudioBox VSL interface on the left column (see example below),
Make sure the AudioBox 1818 is selected as your default Sound Input Device and default Sound Input Device, open Cogwheel at the bottom of the left column, click it to select your AudioBox to be your default interface for Sound Input and Sound Output.
This will effectively toggle your ADAT to function as 24bit 88.2 or 24bit 96KHz with 4 channel light pipe available.
|18 In / 18 Out||24bit||44.1KHz / 48KHz||8 In / 8 Out Analog + SPDIF + 8 In / 8 Out ADAT|
|14 in / 14 Out||24bit||88.2KHz / 96KHz||8 In / 8 Out Analog + SPDIF + 4 In / 4 Out ADAT SMUX|
Select your Format next to Sample Rate, click the drop down to reveal the two different operating modes:
If you've arrived at this tutorial and you're on Mac OS X 10.11 wondering why you're reading this, please review this article detailing AudioBox VSL software and Mac OS X 10.11.