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.

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Audiobus and USB Audio adapter - selecting output?

mardem1976mardem1976
edited April 2021 in Support and Feedback

Hey All,

I'm currently using a Korg B2 keyboard for midi. This keyboard has an analog audio in and out via 1/8" TRS ports, as well as audio and midi over USB. The USB on the keyboard is connected to a ugreen USB hub with audio interface. This device has 3 usb ports, and it's own audio in and out via 1/8" TRS ports. The ugreen hub is connected to the USB camera adapter, which is connected to my iPad.

With this setup, I can input midi through the B2, and audio comes back through the USB connection, which is handy because it can play through the keyboard's speakers, or the headphone jack. What I can't seem to do is get the audio to come out of the ugreen headphone out. This out is "cleaner" than the B2s, with less noise.

Within Audiobus, it only allows me to choose the B2 as an audio out. If I disconnect the USB from the keyboard, it then shows the ugreen as an audio out. What's happening, I presume, is that I'm essentially connecting two USB audio devices at the same time, and Audiobus is only able to show one as an option.

There is no way to disable USB audio on the keyboard, and I don't see a way to disable it in the iOS system. Is there any way in Audiobus to keep the USB from keyboard for midi, but route audio to the uGreen audio out instead of through the USB keyboard?

Thanks for any assistance you can provide.

EDIT: It looks like I found the answer. iOS simply cannot recognize more than one USB audio device at a time, and will use whichever one is farther or newest in the chain. It looks like in my case I can use the headphone jack on the iPad, but not every iOS device has that port. I'll leave this post up here in case anyone is looking for this answer as well.

Comments

  • uncledaveuncledave
    edited April 2021

    Hi. iOS only allows one audio interface at a time. Not sure how it selects, maybe the last one connected/initialized wins. With your configuration, that means the Korg will always be selected. There is no way to configure this, it "just happens". This is not a limitation of Audiobus, it is fundamental to iOS.

    Maybe you can find a way to reduce the noise on the Korg. Is it receiving bus power, or does it have its own power supply?

  • espiegel123espiegel123

    The last connected device wins.

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