TROUBLESHOOTING: About the device is used as a sound system input error

When you start your ingest application, and/or enable a source, you may see an error such as this one:

Error: Your AJA device is used as a sound system input. Go to "System Preferences > Sound" and change the device used

This error is logged because some customers had issues when they used their video device (AJA or Blackmagic-Design) as a sound system input. The issue was that audio was "hashed" from time to time.

If you don't have such an issue, you may ignore that warning, but otherwise you should follow the steps below.


Your Mac has another sound input available 

 Go to the System Preferences > Sound, and select it instead of the AJA or Blackmagic-Design device:SystemPreference_AudioInput.png


Your Mac does NOT have another sound input

Again, let us insist that you may not have audio issues in MovieRecorder, and in that case you can ignore the error log, but if you do have the issue but your computer does not have another audio input available, the card will be selected by default, as in this example:


In that case, you are not able to select a different audio input. There are a few solutions.


Use a "real" external audio device

The best is then to connect to your mac a real audio input (for example a small USB audio device) that you can then use as an audio input for the system.


Use a "virtual" audio device

DISCLAIMER: we are providing this tip as a workaround if you have the audio issue with some devices, but we are not developing nor can take responsibility with the solutions below.

If you can't add a real physical device, you could install a "Virtual Audio device". There are a few solutions around.

  • Loopback: is a paid software from Rogue Amoeba, probably the easier to work with
  • Dante Virtual Soundcard: also a paid option, turns your computer into a Dante-powered workstation
  • Soundflower: this one is free, open-source, but a bit more tricky to work with
  • BlackHole: is an open-source project and you can download a free installer from the GitHub page

These will install virtual inputs and outputs to your Mac that you can use as if there was a real input available. See for example with Soundflower:




Have more questions? Submit a request