I found a thread with a partial unknown solution for using Airplay as playback output here https://forum.audacityteam.org/t/cant-use-airplay-speakers-solved/42013/10 but the OP didn’t really know how he solved it. So after troubleshooting the problem for myself, I figured out definitively how to enable Airplay as a sound output option in Audacity (currently v2.1.2 on OS X 10.11.5):
The solution is simple, but it requires Airplay speakers be selected before launching Audacity. It seems Audacity doesn’t update sound output sources on the fly. So, with Audacity NOT running, go to System Preferences>Sound>Output (or option-click the Volume menu item if it’s showing in the Menu Bar) and select the Airplay device from the list. Then launch Audacity and click the Output drop-down (should read Built-in Output by default) and select Airplay. This will send playback audio to whichever device you have selected in System Preferences, which can be changed again without relaunching Audacity. This process must be repeated everytime before launching Audacity, otherwise Airplay devices won’t be available.
Hope this helps. I’ve sent feedback to the Audacity team asking that they include this process in the User Manual.
Also in the device toolbar page there is a highlighted note:
If you attach or disconnect an external device while Audacity is open, use Transport > Rescan Audio Devices to update the device lists before playing or recording.
I agree that the description is rather sparse for AirPlay users, but AirPlay users make up a minute proportion of Audacity users, and we can’t cover every possible set-up without the manual inflating to the size of an encyclopaedia. What concerned me more when looking up “AirPlay” was how little documentation Apple provide about it.
I use AirPlay a lot and have never had that problem in Mavericks or Yosemite. I can select AirPlay from the drop-down menu in Audacity and it works. Every time. Also, it worked in previous systems, with previous Audacity versions too, for as far as my memory allows me to go back
Do you actually have to reselect the AirPlay device in the Output tab of Sound? Are you quite sure if you select AirPlay once in Sound, launch Audacity, select AirPlay, quit Audacity, then restart Audacity, the AirPlay device is (a) not the selected Audacity playback device (b) is no longer listed as an Audacity playback device?
Now repeat the experiment using GarageBand instead of Audacity. Do you have to keep reselecting the AirPlay device in Sound?
We don’t actually have a FAQ about “why your device is not listed in Audacity”. Perhaps we should have a brief FAQ for that, despite Rescan is mentioned extensively in the body of the Manual. But if your issue is a bug in El Capitan (so GarageBand has the same issue), I don’t think it deserves space in the Audacity Manual.
So after testing Audacity and Garage Band with Airplay, it does seem to be a bug in OS X. I guess it’s limited to El Capitan but I can’t test that since I don’t have a machine running anything older. The only thing I can add to this discovery is that Rescan doesn’t seem to fix the problem without restarting, either.
