So we have to turn to third-party apps to grant us this ability. Both apps on this list offer the feature of adjusting volume by app. However, the apps each bring something different to the table, so explore the options and decide for yourself which is best.
Volume Mixer
Volume Mixer is the first Mac app on the list and it allows you to control system volume by application. The app sits in your menu bar so you can call it up as needed. Each app, much like on Windows, is accompanied by its own volume slider. Adjust it as you’d like, mute individual apps entirely or click Refresh to bring an app on par with the master volume. Over in the Preferences, you can choose your default output source or just quickly change sources on the fly. You can also set highly convenient keyboard shortcuts for specific actions revolving around volume control. These include increasing the volume of an active app, decreasing the volume of an active app, toggling mute for an active app, increasing/decreasing/muting background sound and increasing/decreasing/muting notifications. If you want full control over your output audio, it doesn’t get much better than this. Volume Mixer comes with a free seven day trial after which it’s $9.99 for two copies or $14.99 for lifetime updates. It’s fairly steep pricing, but if you need the features, it works great.
Background Music
Background Music is a simpler app that does much of the same thing as Volume Mixer. From your menu bar, you can adjust volume for individual applications. But in Background Music, the volume sliders aren’t relative to your master volume. Each slider by default is set to the middle and doesn’t change when you raise or lower your volume. That means that technically, if you have your volume all the way up, you could still give some apps a slight boost. It also has a phenomenal feature that auto-pauses your music when another source of audio starts playing, then automatically continues playback when the other audio stops. It’s much like how music stops and resumes when you get a phone call on your iPhone. The auto-pause feature supports iTunes, Spotify, VOX and VLC. Background Music is free, unlike Volume Mixer, but since the developer hasn’t officially published it anywhere, it must be installed from GitHub. Note: The guide to installing Background Music is right on the GitHub page. If you have Xcode installed, just copy and paste the provided prompt into Terminal. To manually install, download the ZIP file and unzip it. In Terminal, type cd followed by the path to where you unzipped the folder. Then install by typing /bin/bash build_and_install.sh. ALSO SEE: How to Live Monitor Your Microphone Input on Mac
