Can an iPad be recognized as a Mac USB input device?

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Level 1

59 points

Can an iPad be recognized as a Mac USB input device?

I'd like to use a percussion app on my iPad Air as an instrument for GarageBand on the Mac. I realize I could run a cable from the headphone output on the iPad to the line input on the Mac, but that's converting a digital signal to analog and then back to digital, it's also prone to noise. Is it possible to plug the iPad's USB cable into the Mac (as I would for syncing with iTunes), but have it show up as an input source in audio preferences. I have tried it but the only devices shown are the line input and my Scarlett 2i2 (also a USB input device). Seems like the digital audio output would to be available on the Lightning port, certainly you can input digital audio to the iPad that way. Might AudioBus be of use here? I've never used it but it claims to allow routing of audio signals between apps, does that also include the iOS device's output?

Thanks

Mac mini, OS X Yosemite (10.10.5), 2012 i7 16GB

Posted on Aug 26, 2015 8:56 PM

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Answer 1

Best reply

seannov29

Level 1

35 points

Aug 27, 2015 11:06 AM in response to A07570

The iPad usb cable's interface is not compatible with audio output. I understand your concern with noise from the output of the headphone amp but I think that in your situation it would be fine as long as you have a good connoting cable from your iPad to the input of your mac. If you want a better quality connection you could plug the 1/8 inch out of your iPad into the Scarlet 2i2 with a connector so that you could use it's higher quality "pro sound" pre ams and convertors.

Hope this helps

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Answer 2

A07570 Author

Level 1

59 points

Aug 28, 2015 8:29 AM in response to seannov29

Thanks for your reply Sean. It surprises me that the digital audio signal isn't available with iOS, possibly Apple feels this would encourage digital piracy. It's unfortunate that the signal must go through an extra DAC and ADC, and travel analog over coax. I'm sure it will sound decent in most situations, but sometimes noise becomes more obvious as you're combining tracks. I also considered going through the 2i2 and might try this, but it would just be using a different ADC, though possibly a better one. I guess I can only suggest to Apple they make provisions for digital output with iOS. Thanks again for your comment.

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Answer 3

A07570 Author

Level 1

59 points

Nov 4, 2015 7:32 AM in response to seannov29

I've since thought more about this, while your response might be true in the context of my question, it's obviously not correct for iOS in general. If I hook my iPhone to the USB port in my car (via a Lightning cable) I can play stereo music digitally, That is, the signal travels in the digital domain and then runs through the DAC in my car's audio system to become analog and play. This would be true of most iPod type docks as well.

So at least the Music app is able to send a digital signal, and unless Apple prevents developers from accessing these API's, other App's should be able to as well. There must be some restrictions (like the Music App tying deeper into iOS) as this isn't commonly used, someone familiar the the SDK would probably know better what the issues are. If piracy is a concern, at least 'instrument' apps (like my percussion example) should be exempt, because I am creating the original output (for better or worse 🙂 ). The Application on the Mac would also need to recognize the iPad as a source device, like it does with the Focusrite, since Apple controls GarageBand, this would also seem possible.

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Answer 4

Dec 3, 2015 4:32 PM in response to A07570

You should be able to keep the audio signal coming out of your iPad and going into your Mac entirely digital. There are at least a couple of ways to do this.

It looks like if you have El Capitan, you're golden. It has a feature called Inter-Device Audio, which will recognize your iPad (via the Audio Midi setup) as an audio device, allowing your DAW to recognize it as an audio input. Whether GarageBand will do this, I'm not sure. But it seems to work for Logic. Here's an article with an accompanying video: http://audionewsroom.net/2015/10/how-to-record-your-ios-device-into-your-mac-daw -on-ios-9-os-x-10-11-welcome-inter-devic…

Another way is to do this is to use the app MusicIO. You connect your iOS device via USB to your computer. It requires the app on your iOS device ($10 in the app store), and a server and plugin for your Mac (a single, free download from the MusicIO website). I use it for both listening to audio from my iPad through my desktop Mac (which has high-quality monitors) and for streaming audio into my DAW (Digital Performer in my case). You can also use it to send MIDI back and forth between the iOS device and a DAW. It takes a bit of practice to get it set up correctly. (My advice is to set it up the audio in the following order: 1) open desktop MusicIO server 2) connect your device to your computer via USB 3) open MusicIO app on your device 4) select which music app you want to use as a sound source and then open up that app [from inside the musicIO app]).

It works... okay. I have eight apps that are supposedly able to work with MusicIO -- they're listed under "available instruments" inside MusicIO. But it actually only works with four of them. But that's okay with me; those four are the ones I really want to use with this app. The degree to which it works well varies greatly among these apps. It works flawlessly with Finger Pro: MoDrum. With SugarBytes' Egoist, the play button seems to disappear and there are only limited ways to play back loops and sequences. But the audio seems fine. With Elastic Drums, there seem to be quite a few audio glitches and even slow downs in the audio playback.

I think how well it all works can depend on how the app developers implement IAA. More about that here: https://musicio.zendesk.com/hc/en-us/articles/204364768-Does-Music-IO-support-Au diobus-Or-Inter-App-Audio-

Even though it doesn't work uniformly for all apps, it was a worthwhile purchase for me. There's nothing like hearing the audio over $600 monitors as opposed to the teeny speakers on my iPad. And it's a much cheaper alternative than some of the hardware interfaces designed specifically for the iOS devices. I'm hoping that some of the problems will get ironed out with future versions of both MusicIO and the music apps.

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Answer 5

A07570 Author

Level 1

59 points

Dec 3, 2015 4:38 PM in response to tunewizardry

Wow, great 'input'! 😁 I will have to take my time to go through all you've outlined here, and follow the links and videos. This all sounds promising, I am using El Capitan, someday I might upgrade to Logic, but only after I learn more of GarageBand (and it's limitations) first. Thanks very much for your detailed response, I'll do my best to digest it all.

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Answer 6

Dec 3, 2015 8:17 PM in response to A07570

Glad the info might be helpful.

You might also give the app Studiomux a look. It works similarly to MusicIO. I just downloaded it and tried it out today. It seems to handle the music apps a little more smoothly than MusicIO, but that may depend on one's setup. I haven't used it enough to give it a fair assessment, but it looks promising. Since both apps are relatively cheap, it may be worthwhile to get both.

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