Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.Download on the App Store
Audiobus is the app that makes the rest of your setup better.
iPad audio to Mac options
I've got a huge collection of iOS apps that are largely unused, and I've started looking into incorporating them into my desktop workflow and I'm trying to figure out the best way to connect my iPads. So far I still haven't found a great solution.
First, I'm not looking to replace my audio interface, so the iConnectivity stuff isn't an option.
I started with the IDAM path, since it's the native option now, and it works reasonably well, with the minor inconvenience of having to change the DAW to use the iPad as the audio device, which prevents simultaneous multitracking without making an aggregate device. It's stereo only as well, which again limits multitracking.
Also for some reason I get slight MIDI latency from my desktop to the iPad, even though the audio is fine. It's relatively usable, but I wouldn't want to really play keys through it.
Studiomux seemed like a great option since it doesn't require changing the desktop audio interface and supports multiple inputs. However, it's completely unreliable, and I've only gotten it to work at all intermittently. When it does work, it's only supporting one app anyway. As soon as I add a second app the audio is full of crackles, regardless of the buffer size, using my 2018 iPad Pro on 12.1.3. But in my testing with it and trying to restart things, getting both audio and MIDI to connect seems to require arcane rituals and proper moon phases. It seems like maybe this app is dead with the introduction of IDAM.
At this point I"m getting close to giving up on trying this path, and just using an audio interface for the iPad and traditional MIDI connectivity to treat the iPad as a standalone module.
Also, as part of this, I noticed that I somehow have my iPad registered as a static 18/2 audio interface and I have not memory of this place. You can see it in this screencap. "The 13" is name of my 2018 12.9" iPad. I wasn't able to actually get this to do anything though.