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.
What USB hub or kind of setup do you use for to MOTU M2 and iPad?
I figured out how to use the M2 interface on my computer, but I am not sure how to get it working on my iPad. I want to feed my Hydrasynth Explorer and Meris Polymoon into it, and I heard that you need a powered USB hub for the M2. It seems like some of the best options on Amazon are expensive.
Does your iPad have a USB-C or Lightning port? The requirements strongly depend on that.
I have Air 4
Apanage Powered USB 3.0 Hub, 11 Ports USB Hub Splitter
My iPad Air 3 used lightning
I have a 3, which uses lightning.
OK. For a Lightning iPad, you need two things: a USB adapter, and a powered USB hub. We generally recommend the Apple USB 3 Camera Adapter. It has a Lightning power input connector beside the USB port, so you can power/charge your iPad while using it. I'd avoid the gimmicky 3rd-party adapters that include SD card readers, video, and other stuff you're not likely to use.
Then, there are lots of hubs. I use this Atolla model. It's nice because it has a separate 2.4 Amp charging port, just right for the iPad power. There's a lot of variety in these, depending on number of ports, etc.
I own two lightning camera adapters, so thank you for that!