If you were considering upgrading you Mac OS X to El Capitan 10.11 I would deeply reconsider that if you are using an Mbox 2 related devices.
Over the last couple of days I've installed OS X El Capitan 10.11 GM Candidate and any updates that were available up to September 23, 2015 on a spare hard drive as I'm apart of the public beta program for El Capitan, and the results are not good if you plan on using your Mbox 2 or related drivers.
My tests were conducted with 10.11 GM Candidate and then updated to 10.11.1 Public Beta 1.
10.3.3 Drivers - Installed fine, all green lights on Mbox 2 device are bright green as if everything is working fine, Both directly connected to USB port and via Hub. The preference pane for the Mbox 2 says it's not connected, and under sound (System Preference) it doesn't show up at all. So there is some sort of connection but it does not register at all and it basically useless at the moment, but maybe Avid can do some investigating and work with Apple to find a resolution to the problem.
10.3.9 Drivers - Installs fine, lights are all dim with really no signs of life. Both directly connected to USB port and via Hub, The preference pane for the Mbox 2 says it's not connected, and under sound (System Preference) it doesn't show up at all. So just like Yosemite this driver is DOA.
So these are the results of testing both drivers, as it stands El Capitan 10.11 is your Mbox 2 Killer, unless someone finds a possible solution.
Over the last couple of days I've installed OS X El Capitan 10.11 GM Candidate and any updates that were available up to September 23, 2015 on a spare hard drive as I'm apart of the public beta program for El Capitan, and the results are not good if you plan on using your Mbox 2 or related drivers.
My tests were conducted with 10.11 GM Candidate and then updated to 10.11.1 Public Beta 1.
10.3.3 Drivers - Installed fine, all green lights on Mbox 2 device are bright green as if everything is working fine, Both directly connected to USB port and via Hub. The preference pane for the Mbox 2 says it's not connected, and under sound (System Preference) it doesn't show up at all. So there is some sort of connection but it does not register at all and it basically useless at the moment, but maybe Avid can do some investigating and work with Apple to find a resolution to the problem.
10.3.9 Drivers - Installs fine, lights are all dim with really no signs of life. Both directly connected to USB port and via Hub, The preference pane for the Mbox 2 says it's not connected, and under sound (System Preference) it doesn't show up at all. So just like Yosemite this driver is DOA.
So these are the results of testing both drivers, as it stands El Capitan 10.11 is your Mbox 2 Killer, unless someone finds a possible solution.
Digidesign Mbox Driver Windows 10
Hook up the Mbox to the computer first, then connect a hard drive to the second port on the Mbox. I have two hard drives connected via the Mbox right now.daisy chained. Connected as such. Macbook Pro-Mbox-HDD1-HDD 2. Works very well. However it doesn't beat having a Mac Pro and internal hard drives or multiple firewire ports. If you have Problems under macOS High Sierra 10.13 or Mojave 10.14 and your RME Audio Interface is not being recognized, TotalMixFX can’t be opened or having.