For everyone else I can find on the Internet, this configuration seems to work. However, when I look up what other people do, I find no one else seems to have a problem plugging an audio interface AND a MIDI controller at the same time into a hub and then into the Camera adapter to the Ipad. This seems to happen with Cubasis as well as other music programs on my iPad Air 2, such as GarageBand. HOWEVER, as soon as I plug any one MIDI controller in the hub and any ONE Audio interface into the hub at the same time, the MIDI controller cuts out and only the Audio Interface works. I can even plug two MIDI devices into the either USB hub and then into the Lightning USB3 Camera Kit to the iPad and both MIDI devices work. Each individual device works fine directly into my Lightning USB3 Camera Kit to the iPad Air 2 or through an Anker or Tripp-Lite powered hub alone.
No matter which audio interface (I have the Steinberg UR 44 and the Zoom U-24)and MIDI controller (I have the M-Audio Axiom Air 32, the Maudio Oxygen 25, and the M-Audio Axiom Air 61 and the Samson Graphite 49 USB keyboard) combination I try, I get the same problem. I have two different audio interfaces and four different MIDI controllers and two separate powered hubs and no matter what configuration I try, I cannot get one Audio interface and one MIDI controller to work at the same time through a powered hub into my iPad, using an Apple Camera Kit Interface. Can’t use an Audio interface and MIDI controller at the same time using a powered hub into my iPad Air 2 (using the Apple USB3 or USB2 Camera Adapter kit).