I run GarageBand on my MacMini with a simple USB audio interface. I want to be able to play my electric guitar through GarageBAnd so the sound with SFX is what is fed into Skype and other video chat sites, as if this were my microphone.

But I think selecting the USB device as my audio input will give me only the dry sound from my instrument, not the modified sound from Garageband? So how can I do what I want without expensive equipment?

I have realised my USB interface has a mixer inputs/playback which means through headphones I can choose to select only the processed output from GarageBand if I set the interface as my audio-out... but how do I get that back into the Mac short of putting a cable from the headphone-out => Mac line-in?!

  • Have a look at Blackhole which is a modern Soundflower replacement. [I've never used it, I use Audio Hijack which is a brilliant, but paid, alternative]
    – Tetsujin
    Apr 20, 2020 at 16:33
  • That sounds neat, though in that context the ideal would be to set AH as a "virtual audio input" so other apps could treat it as such without knowing it's even running?
    – Mr. Boy
    Apr 20, 2020 at 21:39
  • But it sounds quite a general solution, I had the ideas DAWs could sort of do this anyway to chain apps together?
    – Mr. Boy
    Apr 20, 2020 at 21:40
  • Though it seems my "virtual device" is what SoundFlower does": iandunn.name/2017/04/04/…
    – Mr. Boy
    Apr 20, 2020 at 21:43

1 Answer 1


I just used the Blackhole.‌ It worked perfectly.

At the very high level you have to do these things:

Follow these screenshots and steps to:

  • Add blackhole to your OS. It's not an app you install. It's a package. Once you install it. This creates a new audio device ie adds an item named blackhole to the list of your audio inputs and outputs.
  • Create a Multi-output device (I did blackhole + Headphone) using your Mac's Utilities.


  • In Garageband you set your output to that blackhole (not Multi-output)
  • In Skype your set your Mic input to that blackhole (not Multi-output)
  • Done! Begin speaking into your primary audio input source (I used my Mac's microphone)

All the steps are mentioned in detail here. Garageband is the 'sending application'. Skype is the 'receiving application'

The end result for me looked like like:

Create new project:

enter image description here

GarageBand Settings

enter image description here

I've also been told that you can achieve the same using the Loopback app.

btw, everything I mentioned in my answer is free.

  • was trying this out with Zoom and airpods, I did the same, garageband can play to the other person, but then my voice via the airpods mic doesn't go through. Do I need an aggregate device for this?? Jun 5, 2020 at 6:48
  • Did you see these steps? I only created a multiOutput device. Your should have something like this. Where you have a Blackhole device AND multi-output device (which is a combo of blackhole device + another physical). I made my combo with the Airpods because I wanted to use my mac's mic as my input. If this doesn't work then open a question (and share it) with screenshots of your OS devices, garageband input/outputs + zoom's input/output
    – Honey
    Jun 5, 2020 at 14:38
  • I managed to get mic through to zoom with a new voice track and turning on monitoring. Is that how you do it as well? Jun 5, 2020 at 15:15
  • I don't know what "new voice track means" Can you share a screenshot? For zoom ie receiving application the audio input should be set to the multipoutput device you've created yourself
    – Honey
    Jun 5, 2020 at 16:49
  • 1
    Great that it’s working now
    – Honey
    Jun 6, 2020 at 13:38

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