USB Audio - Multiple Devices

Unlike desktop OSs like MacOS, iOS/iPadOS does not readily allow multiple USB audio devices to be used simultaneously. For instance, you can’t receive audio input from two different audio interfaces at once or from an audio interface and a digital piano that sends audio over USB.

The general rule is that the last device connected wins, but it is sometimes possible to get things set up so that one device is used for input and a second device can be used for output. Whether or not this works depends on the OS version and the particular devices.

Checking available input and devices

If you have two or more USB devices connected that may be interfering with each other, the first thing to do is to check to see what devices the OS sees. It will have selected the last connected device to be both the input and output device. The procedures below will let you see if there are other available devices.

Checking Available Input Devices

• In Loopy Pro, create a new project using Loopy Pro's default project.
• Show the Loopy Pro mixer.
• Tap on the icon at the top of the hardware input channel.
• Tap next to Input Selection to see the list of input devices.

Checking Available Output Devices

Use the system's Control Center to see what output devices the OS sees. The details may vary slightly on some versions of the OS. If these don't work, find out how to display Control Center on your device by searching on the web.

• Swipe down from the upper-right corner to display the Control Center.
• On most devices, the upper-right tile will be for sound output. Tap it.
• Tap on the Speaker icon (circled in the picture below) to see a list of the possible output devices.
• You should see something like the picture below that shows the names of the possible audio outputs.

Different Input and Output Device

In order to use different input and output devices, try the following steps:

Open or create a Loopy Pro project that has some pre-recorded audio.

Set the input device

In Loopy’s mixer:

• Tap on the icon at the top of any hardware input channel.
• Tap on Input Selection and choose the device that you would like to use for audio input.
• Make sure the mixer channel is unmuted.
• Play some audio on the input source and see if it registers In the mixer.

Set the Output Device Using Control Center

In Control Center, display the available audio output options as described earlier and choose your desired output device.

Check to see if this worked.

Check to see if this worked by playing the pre-recorded audio. If this worked, confirm that you can record by recording some audio from the input source.

If recording and playback worked you are set.

If that did not work, see the next section: Multiroute Audio.

Multiroute Audio

The OS has a feature called Multiroute Audio that may permit a different input and output device to be used. It may allow both devices to be used as output devices.

To turn on Multiroute Audio, choose System Settings from Loopy Pro’s main settings and turn on Multiroute Audio. You will get a warning asking if you want to turn this on. Choose Enable Multiroute Audio

The output destination of every mixer channel can now be set to either of the connected devices.