Mac Audio for Twitch Streaming: Game, Alerts, Music

You're live on Twitch from your Mac. The game is running, a stream alert fires, Spotify plays in the background and Discord is open for your mods. If all of that reaches your viewers at whatever level each app happens to use, alerts blast over gameplay, music covers your commentary and a Slack ping lands in the middle of a clutch moment.

Here's how to get each sound to a sensible level, first in OBS and your apps, then on your Mac.

Why this is harder on Mac

macOS has one output volume for every app. There's no built-in panel where the game, alerts and music each get their own slider, the way Windows has a volume mixer. So the levels have to be set somewhere else: inside your streaming software, or inside each app.

Step 1: Split your sources in OBS

The most direct way to control what viewers hear is to give each sound its own fader in OBS:

• Microphone as its own input
• Game as its own audio source
• Music as its own audio source
• Alerts from your alert service, usually via a browser source in OBS that carries its own audio
• Desktop audio for everything else, or leave it out if you capture apps separately

Recent versions of OBS on recent macOS versions offer a macOS audio capture source that can be set to one application instead of the whole desktop. Look for it under the + button in the Sources list; names and options depend on your OBS and macOS versions.

Once each source has its own fader in OBS's Audio Mixer, you set stream levels there. That doesn't change what you hear in your headphones.

Step 2: Set levels inside each app

Many apps have their own volume, and it's worth setting them before you go live:

• Games: most have separate sliders for music, effects and voice in their audio settings. Turning the in-game music down often helps more than lowering the whole game.
• Spotify or Music: use the app's own volume slider, and keep it low under your voice.
• Alerts: your alert service usually has a volume setting per alert, which is easier than fixing it in OBS later.
• Discord: has its own output volume in its voice settings, and lets you change the volume of individual users.

A starting point for stream levels

• Your voice: the loudest thing on stream
• Game: present, but under your voice
• Alerts: audible, never louder than a shout in the game
• Music: low, in the background (check Twitch's current music guidelines for what you're allowed to play)
• Slack, Mail, Messages: muted, viewers don't need your DMs

Do a short test recording and listen back before going live. What sounds right in your headphones can sound different on stream.

Step 3: Per-app volume on your Mac with SoundDial

SoundDial, a per-app volume mixer for Mac puts a slider and a mute button for every running app in your menu bar. Each app goes from 0% to 200%, so you can turn the game down, boost a quiet Discord call above 100% and mute Slack with one click, while everything else keeps playing.

SoundDial changes what you hear on your Mac. Whether those levels also reach your stream depends on how OBS captures your audio, so test it with a short recording. If you capture each app as its own source in OBS, you'll usually still set stream levels in OBS's Audio Mixer.

Where it helps during a stream:

• Your own monitoring: a viewer says the game is loud, and it's loud in your headphones too. Drag its slider down from the menu bar instead of opening the game's settings.
• Quick mutes: silence a notification-heavy app for the length of the stream.
• Quiet voice chat: boost Discord on your end when a mod's mic is weak.

You can save your stream mix as a profile and apply it to the running apps with one click. One thing to check before going live: auto-ducking is on by default, so while Discord (or another call app, including a browser) uses the microphone, SoundDial lowers your other apps, the game included, to 30% of their level. If you talk to mods in Discord during a stream, turn auto-ducking off or raise the duck level in SoundDial's settings. It works per app, not per browser tab (all tabs of a browser share one slider), and it does not record anything.

More on the basics in per-app volume control on Mac. For OBS-specific setup, see Mac audio for OBS and streaming.

SoundDial 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.