// the find
ronitsingh10/FineTune
FineTune, a macOS menu bar app for per-app volume control, multi-device output, audio routing, and 10-band EQ. Free and open-source alternative to SoundSource.
FineTune is a macOS menu bar app (Sequoia 15+ only) for per-app volume control, audio routing to multiple outputs simultaneously, a 10-band EQ with AutoEQ headphone correction, and DDC monitor volume control. It's a free GPL alternative to Rogue Amoeba's SoundSource, aimed at anyone who wants more audio control than macOS provides out of the box.
- The audio engine architecture is well-structured — separate concerns for tap management, crossfade orchestration, and EQ processing with protocols like ProcessTapControlling and BiquadProcessable suggest it's testable and not a giant singleton.
- Test coverage is real and specific: BiquadMath adversarial tests, ISO226 loudness contour tests, settings migration fixtures (v10/v11), and media key decoder tests. Not just happy-path unit tests.
- AutoEQ integration is a genuine differentiator — fetching and parsing thousands of headphone profiles plus supporting EqualizerAPO ParametricEQ.txt import is non-trivial and directly useful.
- URL scheme automation support makes it scriptable from Terminal, Shortcuts, or Raycast, which is something SoundSource charges for and most menu bar audio apps skip entirely.
- macOS 15+ only is a hard cutoff that will block anyone on Ventura or Sonoma. The ProcessTap API that makes per-app audio interception work was introduced in Sequoia, so this isn't easily backported, but it's worth knowing you're locking out a large installed base.
- Single contributor project with 214 forks but no visible co-maintainers listed in CONTRIBUTING.md. Bus factor is 1, and the audio tap/CoreAudio layer is complex enough that bus-factor-1 is a real adoption risk for anything depending on it long-term.
- The project uses `Screen & System Audio Recording` permission, which means it shows up as an app that can record your screen — this causes friction in enterprise or security-conscious environments and some users will hit permission prompts from IT policy.
- No architecture documentation or ADRs explaining why specific CoreAudio design choices were made (e.g., the crossfade orchestrator, software vs hardware volume detection). The code structure is clean but the reasoning is opaque, making contributions to the engine layer harder for new contributors.