sound-control-mac

Menu bar macOS app for per-app audio control with persistent app profiles.

Implemented

• SwiftUI menu bar UI (MenuBarExtra) with:
  • DEVICE section:
    • Output/Input tabs
    • Per-device row controls (default-device radio, icon, name, slider, typed percentage input)
    • Per-device hardware volume control when supported, with DDC fallback for external display audio outputs
    • Per-device 10-band EQ for output devices (32Hz to 16kHz, low-to-high left-to-right; per-app EQ overrides per-device EQ)
  • APPS section:
    • Per-app volume slider
    • Per-app mute toggle
    • Inline editable per-app percentage
    • Expandable per-app 10-band EQ (32Hz, 64Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz, 16kHz)
• Global output/input default device selection through CoreAudio.
• Profile persistence per bundle identifier with optional "remember" toggle.
• Settings UI for enabling/disabling remembered app profiles and overriding system volume shortcuts, with optional raw F11/F12 capture and configurable shortcut step size.
• Runtime-only profile mode when remember is disabled.
• Core Audio tap routing service (CoreAudioTapRoutingService) that:
  • Resolves PID to CoreAudio process objects
  • Creates per-app process taps (AudioHardwareCreateProcessTap)
  • Creates private aggregate devices and IOProc callbacks
  • Applies per-app mute/volume and 10-band EQ DSP in the callback path
  • Hard-clamps output samples to [-1, 1] to avoid clipping overflow
• Fallback StubRoutingService when taps are unavailable.

Current Limitations

• Core Audio tap flow requires macOS 14.2+.
• Per-device hardware volume may be unavailable for some devices/scopes (shown as disabled with N/A).
• DDC control depends on the display exposing speaker volume controls over DDC/CI.
• Global F11/F12 interception may require macOS privacy approval for keyboard event capture.
• Per-app input source routing is not implemented.
• Tap-based routing reliability still depends on process/device behavior in HAL; additional hardening is still needed for production.

Build

swift build

Test

swift test

Xcode App Project

• Open SoundControlMac.xcodeproj in Xcode.
• Scheme: SoundControlMac
• Target: SoundControlMac
• Deployment target: macOS 14.2
• Bundle ID: com.minkyu.soundcontrolmac

CLI validation command:

DEVELOPER_DIR=/Applications/Xcode-16.4.0.app/Contents/Developer xcodebuild -project SoundControlMac.xcodeproj -scheme SoundControlMac -configuration Debug -sdk macosx build

Project Structure

• Sources/SoundControlMac/App: app entry and app delegate
• Sources/SoundControlMac/Models: domain models
• Sources/SoundControlMac/Services: CoreAudio device manager, app monitor, routing services
• Sources/SoundControlMac/Stores: persistence and app-level state store
• Sources/SoundControlMac/Views: menu bar and settings SwiftUI views
• Tests/SoundControlMacTests: persistence tests