Mac Audio for DJing: Monitor and Output Separately

You're DJing from your Mac with Traktor, Serato, rekordbox or a live set in Ableton. You need to cue the next track in your headphones while the audience hears the current mix through the speakers. And you don't want a Messages ding or a browser tab coming through the PA in the middle of a set.

Those are two separate problems, and they have separate answers.

Problem 1: cue in headphones, main mix to the speakers

macOS sends ordinary app audio to one output device at a time. That's why DJ software doesn't rely on it for cueing: it handles the split itself.

What you need

• Hardware with a separate headphone output. Most DJ controllers have a built-in sound card with a master output for the speakers and a headphone output for cueing. A multi-output audio interface works the same way.
• Your DJ app set up to use it. In your DJ app's audio settings, choose the controller or audio interface as the audio device, then assign the main mix to the master outputs and the cue to the headphone outputs. Names differ between apps, so look for the output or audio setup section and the mixing mode options.

Check it before the gig

1. Connect the controller or interface before opening your DJ app, so the app finds it at launch.
2. Load a track, press the cue button on one deck and confirm you hear it only in the headphones.
3. Raise the channel fader and confirm the main mix comes out of the master outputs.

If you try to cue with only your Mac's built-in output, you'll hear everything in one place. Your Mac's single output can't do the split on its own; the DJ hardware is what makes it work.

Problem 2: the rest of your Mac is still making noise

Depending on how you've set things up, your Mac's other sounds may come out of the same device as your mix, or out of the built-in speakers right next to you. Notifications, a browser tab with your setlist, a calendar reminder: any of them can interrupt.

Native steps

• Turn on a Focus (such as Do Not Disturb) in Control Center. It silences notification alerts from most apps. It doesn't stop an app from playing audio it's already playing, such as an auto-playing video in a tab.
• Quit what you don't need. Close chat apps, mail and any tab that might play audio.
• Check System Settings > Sound. Look at which device is the system output and set the alert volume low.

Mute the other apps with SoundDial

SoundDial, a per-app volume mixer for Mac gives every running app its own slider and mute button in the menu bar. It doesn't send apps to different devices; it controls how loud each app is. (Its panel can switch the Mac's system output device, but that moves all apps together, not one.)

For a set, that's useful as a safety layer:

• Your DJ app: leave it at 100% and do your levels in the DJ software and on the hardware
• Browser: muted, so a tab can't start playing out loud
• Slack, Messages, Mail, Calendar: muted, so no dings or chimes come through
• Spotify or Music: muted

You set these by hand before you start, and unmute them after the set. If you play often, you can save this as a profile and apply it to your running apps with one click. See how muting one app on Mac works.

Good to know:

• It works per app, not per browser tab: all tabs of a browser share one slider.
• It does not record anything.
• It needs macOS 14.2 or later and costs €14.99 one-time purchase on the Mac App Store, no subscription.

For production work outside of sets, see Mac audio for music production and DAWs.

Get SoundDial on the Mac App Store.