I use Soundsource for specifying which audio interface an app should use to play its audio output. But it only works for output, not input. Is this a system limitation, or is anyone aware of an app that lets you do the same for audio input?
(My use case is that I want to use my Studio Display microphone for most things, but use my headset for phone calls with my VOIP app)
Iāve never used Loopback, also by Rogue Amoeba, but thatās the first app Iād investigate if I needed to do what youāre describing.
Thanks. I have a Loopback license, so Iāll check it out, although I always thought it an app to combine interfaces, rather than assign apps to inputs, etc.
SoundSource lets me set audio Inputā¦ what am I missing?
Alternatively you can use the āAudio MIDI Setupā app which comes free with your Mac; it lets you create an āAggregate deviceā which includes both inputs and outputs (or multiple selections of each simultaneously).
Iād like to set the input automatically per-app, like you see down at the bottom of your screenshot for output. The part under āApplicationsā in the screenshot is only for directing output, not for selecting which input (i.e., which microphone) to use in each app. So I canāt set a different input for Zoom, for a VOIP app, etc. They all have to use the same microphone unless I manually switch it.
You could look at Ears ā retina studio
Itās AppleScript-able for setting sound inputs and outputs. Maybe that could be connected to keyboard maestro triggers?
Thanks! Even if I canāt get it working, that looks like the sort of app I love fiddling with. Iād never heard of it before. Iāll definitely check it out.
You can use Audio MIDI Setup to create an Aggregate Device for each of your apps. Each aggregate device may include one or more input devices and one or more output devices.
Then in SoundSource set the audio redirect option to the applicable Aggregate Device for each application.
Thank you. Maybe Iām not understanding this thoroughly, but wouldnāt this run into the same issue of Soundsource only pointing to one input at a time? In other words, even if create multiple Aggregate Devices, I can only point to one of them at a time? Or are you saying that by combining an input and output into one aggregate device, I can point to it as an output and it will use the paired input I set up as an aggregate device, and I can ignore Soundsourceās input setting?
Your suggestion led to me looking into all the interesting apps at retina studio. Didnāt need the Ears app but liked the look of their ReBudget app, so I purchased it. 
Yes. You can create an aggregate device for each app you want to use and assign it in Soundsource to override the default audio device(s) on a per-app basis.
Cool, Iāll give it a try. Thank you.
Totally going off the top of my head here, but I think most (all?) apps that take audio input should have a setting to say which? I know MS Teams and Skype do, for instance.
Even if some donāt, if you want āmost thingsā to use the SD microphone, then set that as your system input, and set your VOIP app to use the headset. Certainly with the two I mentioned that setting will stick if the headset is plugged in when the app starts (in the case of Teams).
The ones I use have that setting, yes, but Iāve found it to be unreliable. Perhaps Soundsource confuses things in that there can be two apps giving conflicting choices on the sound input.