You want to listen to two audio sources at the same time. Music while on a call. A podcast while watching a tutorial. Background ambiance while studying. Two things, two different ideal volumes. macOS gives you one slider for both.
This is the fundamental audio limitation of macOS: every app shares one volume. You can't say "this one at 30%, that one at 80%." It's everything at one level, or nothing.
When you actually need two audio sources
This isn't an edge case. It's how most people use their computers:
- Music + video call — the most common. Background music during a Zoom meeting, but quiet enough to hear colleagues.
- Lecture + reference material — a student watching a recorded lecture while occasionally watching a YouTube tutorial for context.
- Podcast + ambient sounds — listening to a podcast while a white noise or rain sounds app plays softly.
- Two browser tabs — a training video in one tab and a demo in another, at different volumes.
- Game + voice chat — game audio for immersion, Discord for communication.
In every case, one source is "primary" (louder, more important) and the other is "secondary" (quieter, supportive). The ideal ratio is different for each combination, and it changes throughout the day.
The macOS limitation
macOS has one volume slider. Press the volume key and everything changes equally. If you set the volume for comfortable podcast listening, the rain sounds app is also at that level — either too loud (distracting) or you haven't adjusted it in its own app (if it even has a volume control).
Some apps have internal volume sliders (Spotify, VLC), but most don't. And even when they do, switching between apps to adjust two separate volume controls is clunky and slow.
The fix: per-app volume in one panel
SoundDial puts every app in one menu bar panel with independent volume sliders. Both audio sources, side by side, each with their own level. Adjust one without touching the other.
Example setups:
Music + Zoom call:
- Zoom: 100% | Spotify: 20%
Podcast + rain sounds:
- Podcast app: 70% | Rain app: 15%
Lecture + YouTube tutorial:
- Zoom (lecture): 90% | Chrome (YouTube): 40%
Each combination is a different balance. Save the ones you use regularly as volume profiles and switch with one click. Auto-ducking handles the music+call scenario automatically — when a call starts, music drops to your configured level without you touching anything.
Get SoundDial on the Mac App Store — €14.99 one-time purchase, no subscription, macOS 14.2+.