TeenySound vs SoundSource vs Background Music

macOS still treats system volume as a single shared control. That is fine until a browser tab is too loud, a call app needs to stay audible, or music should go to headphones while alerts stay on speakers.

The short version: teenysound is for people who want per-app volume and app routing in a native menu bar app without installing a driver. SoundSource is a broader audio control panel with EQ, effects, automation, and AirPlay support. Background Music is free and open source, but it uses an older virtual-device model and its own GitHub page still calls the app alpha.

Quick comparison

Pick TeenySound if you want the small mixer

teenysound focuses on the everyday audio problem: one app is too loud, another app is too quiet, and macOS gives you no mixer. It lives in the menu bar and shows audio-producing apps as they appear.

The controls are deliberately narrow. You get per-app 0 to 100% volume, per-app mute, a mute-all shortcut, a shortcut to open the mixer, per-app output routing, and volume memory for each output device. The defaults are Option+Shift+A for mute all and Option+Shift+S for opening the mixer, and both can be changed.

The implementation matters if you dislike audio driver installs. teenysound uses Apple's CATap API on macOS 14.2 or later. The app still needs System Audio Recording permission because that is how macOS gates CATap access, but it does not install a virtual audio device, kernel extension, or system extension. The permission-specific guide is why Mac volume apps ask for system audio recording.

Pick SoundSource if you want more than volume

SoundSource is the widest app in this comparison. Rogue Amoeba's product page lists per-application volume, per-app output redirection, built-in audio effects, Audio Unit support, AirPlay output, device groups, Shortcuts support, and fast access to output, input, and sound effects devices.

That extra surface area is useful if you actually need it. A podcaster, streamer, or audio-heavy Mac user may want EQ on one app, a grouped output device, or Shortcuts workflows for changing audio setups. SoundSource is built for that kind of control.

The tradeoff is price and scope. Rogue Amoeba lists a SoundSource license at $49 USD, with a free trial. If all you need is a menu bar mixer for app volume and routing, you may be paying for features you will not open.

Pick Background Music if free is the requirement

Background Music is the budget answer because it is free and open source. Its GitHub page lists per-application volume control, automatic music pause and unpause, and system audio recording. It also says it requires macOS 10.13 or later.

The project takes a different route than teenysound. Background Music sets itself as your default output device when it starts, then switches the default output back when it quits. Its setup notes also mention microphone permission because macOS treats the virtual input device as microphone-like access, even though the app says it is not listening to your microphone.

That may be perfectly acceptable. It is a good fit when the price has to be zero and you are comfortable with GitHub-hosted software. I would be more cautious on a work Mac or a machine where audio reliability matters, because the project page still labels it alpha and lists a current download of version 0.4.3.

Where the differences show up

For basic per-app volume, all three belong in the conversation. The practical differences are setup, breadth, and how much app you want around the mixer.

• Per-app volume: all three support it.
• Per-app output routing: TeenySound and SoundSource both support app-specific output routing. Background Music's public overview is centered on per-app volume and system audio recording, not routing individual apps to separate speakers.
• Effects and EQ: SoundSource is the clear choice if you want built-in effects, 10-band EQ, or Audio Unit plugins.
• System audio recording: Background Music lists recording system audio as a feature. TeenySound is not a recording app.
• Driver-free setup: TeenySound is the narrow driver-free option here, because it uses CATap and does not install a virtual audio device.
• Older macOS support: Background Music goes back to macOS 10.13. TeenySound requires macOS 14.2 or later because it depends on CATap.

My recommendation

Use teenysound when you want the missing Mac volume mixer and you do not want a larger audio workstation around it. It is the cleanest fit for per-app sliders, per-app mute, output routing, and a fast mute-all shortcut.

Use SoundSource when effects, EQ, AirPlay, device groups, or Shortcuts automation are part of the job. Use Background Music when free and open source matters more than polish, and you are comfortable with an alpha project that works by becoming the system output device while it runs.