Play One App Through Headphones on Mac, the Rest on Speakers

Short answer: macOS sends every app to the same output. With SoundDial, open ⋯ → Play Through next to an app and choose your headphones; the other apps keep playing on your speakers.

You want your music on the desk speakers and your meeting in your headphones. Or a video playing through the TV while a call stays private in your ears. On a Mac, the moment you change the output device, everything follows it: the call, the music, the browser, every notification. There's one output, and every app has to share it.

The problem: one output for everything

Having more than one audio device is normal now. Headphones, the built-in speakers, a USB DAC, a monitor with speakers, AirPods. What you often want is to assign apps to devices: calls to the headset, music to the speakers. macOS makes you pick one, and switching back and forth every time a call starts gets old quickly.

What macOS gives you

In recent macOS versions, System Settings > Sound > Output is where you pick a single output device, and every app that follows the system setting plays through it. There's no list of apps and no per-app choice.

Audio MIDI Setup (in Applications > Utilities) is the usual next stop, and it's worth being clear about what it can do:

• A Multi-Output Device sends the same audio to several outputs at once. Every app plays on every device in the group, so it doesn't separate apps.
• An Aggregate Device combines several devices into one larger device. It's mainly for recording and pro audio setups, and again it has no concept of individual apps.

A few apps have their own output setting (many call apps let you choose a speaker device, for example), but plenty don't, and each one hides the option somewhere different. There's no single place to decide which app goes where.

How to send one app to headphones with SoundDial

SoundDial is a menu-bar app that gives each app that plays sound its own volume slider. Version 2.0 adds per-app output with Play Through: several apps can play on different devices at the same time.

1. Connect both devices, for example your headphones and your speakers.
2. Open the SoundDial popover from the menu bar or with Control-Option-S.
3. Make sure the app you want to move is playing so it appears in the list.
4. Click ⋯ on that app's row and open Play Through.
5. Choose the output device, for example your headphones. The app now plays there, while the other apps stay where they were.
6. To undo it, open Play Through again and choose Same as the app (default).

The app's row shows the device name as a chip, so you can see at a glance which apps are playing elsewhere. If the chosen device is disconnected, the app falls back to its own device, then to the system default.

SoundDial also has an output card with a device menu, so you can change your main output and move individual apps away from it in the same place.

Practical setups

Setup	Main output	Play Through
Music in the room, calls private	Speakers	Zoom / Teams → headphones
Hi-fi music, normal everything else	Built-in speakers	Spotify → USB DAC
Video on a monitor, chat in your ears	Monitor speakers	Discord → headphones

Home office. Keep Spotify on the speakers and send Zoom to your headphones. The setting Lower other apps during calls is on by default, so when the call starts, other apps play at 30% of their volume and come back when the call ends. The calling app itself is never lowered. You can set the level anywhere from 5% to 80%.

Gaming. Game audio on speakers, Discord on your headset, then use the per-app sliders (0% to 200%) to balance them. One thing to know: Discord counts as a call app, so while it uses your microphone, SoundDial lowers the game. If you want the game at full level during voice chat, raise the level under Lower other apps during calls (up to 80%) or turn the setting off.

Streaming on the TV. Send your browser to the TV or monitor output while a messaging app stays on your headphones, so notifications don't interrupt the film for everyone in the room.

For a music-and-calls walkthrough, see Play Music on Speakers and Calls on Headphones (Mac). To put one music app on a DAC, see Send Only Spotify to Your USB DAC on Mac.

Automating it

If you switch setups often, you can script the output choice:

• In the Shortcuts app, Set App Output Device sends an app to a device, and Set Output Device changes the main output. Both work without opening a window.
• A link like sounddial://route?app=Zoom&device=Headphones does the same from any launcher or script that can open a URL, or with open in Terminal.

Limits worth knowing

• Profiles don't store the output device. A profile saves every app's volume, mute, EQ and balance, but not Play Through. If you want one click that does both, build a Shortcut that runs Apply Volume Profile and then Set App Output Device.
• Per app, not per browser tab. Moving Chrome moves all of Chrome's tabs. SoundDial groups browser helper processes under their app, so the whole browser goes to the chosen device.
• Stereo only. SoundDial is not a surround or multichannel tool.
• System UI processes get no slider, so they can't be moved separately.

Common questions

Can two apps really play on two devices at the same time?

Yes. That's what Play Through is for: each app can play on a different device at once, for example music on speakers while a call stays on headphones.

Why didn't my output choice come back when I switched profiles?

Profiles don't store it. They cover volume, mute, EQ and balance. Use the Shortcuts actions or a sounddial://route link if you want the output choice as part of a one-click setup. With Settings > General > When an app opens set to Remember last, SoundDial does bring back each app's output device when the app opens.

Does it work with browser calls like Google Meet?

You can move the browser with Play Through like any app. Lowering other apps during calls also reacts to Safari, Chrome, Firefox, Edge, Arc, Brave, Opera and Vivaldi when they report the microphone in use. SoundDial does not read or record microphone audio.

What does SoundDial need to do this?

macOS 14.2 or later and macOS's System Audio Recording Only permission (under Privacy & Security > Screen & System Audio Recording). If audio access isn't working, the popover shows Fix It, and Settings > Setup & Help has Check Again and Open Guided Setup. SoundDial changes levels; it has no network entitlement and no account.

SoundDial, a per-app volume mixer for Mac needs macOS 14.2 or later and costs €14.99 one-time purchase on the Mac App Store, no subscription.

Get SoundDial on the Mac App Store.