

MJSFX
Native macOS studio for creating game, interface, and retro sound effects. Start with generators, layer oscillators, and shape them using envelopes, filters, effects, and LFOs. Map controls through MIDI, save sounds in libraries, and export WAV files or per-layer stems.
Cost / License
- Free
- Proprietary
Platforms
- Mac
Features
- No Tracking
- No Telemetry
- Model Context Protocol (MCP) Support
- Export to WAV
- Sound Effects
- Built-in editor
MJSFX News & Activities
Recent activities
MJSFX information
What is MJSFX?
MJSFX is a native macOS sounds and effects design studio.
The whole app is one tight creative loop: start from a generator, listen, adjust, tweak, play, and export a drop-in WAV.
• FREE. No ads, no telemetry, and you own everything you make. • Generators: Curated starting points for pickups, lasers, explosions, jumps, hits, power-ups, and UI blips. Pick one and you're already in the ballpark. • Layers: Stack multiple voices into a single sound, each with its own pitch sweep, amplitude envelope, and filters. • Effects: Per-layer chains of Reverb, Delay, Distortion, Bitcrush, Tremolo, Phaser, and ADSR. Drag to reorder; the signal flows left to right. • LFOs: Bring sounds to life: modulate pitch, filters, effect parameters, layer gain, and even other LFOs. Six waveshapes, loop or one-shot, live animated scopes. • Sound Portrait: Waveform, amplitude, and pitch fused into one live, color-coded image that redraws on every change. See what you hear. • Library: Save your sounds and reopen them as documents. Unsaved work is restored on relaunch. • Workspaces: Create and switch between separate sound libraries. • Formulas: Builds arps, octave stacks, runs, and harmonic stacks as new layers on top of the active layer • Themes: 20 built-in themes, light and dark, plus custom JSON themes you can install with a double click. Every visualization color is themeable. • Keyboard first. Drive the entire faceplate from the keyboard, jump between layers with Cmd-1 through 9, and customize every shortcut. • Extensive MIDI Support: Map knobs, faders, and pads to parameters, effects, LFOs, gains, and actions. Set an active layer's frequency to a MIDI note's exact Hz. • Explore: Mutate every parameter for a fresh take, or randomize a brand-new sound. Every edit is undoable. • No in-app AI, but the direct download (site or homebrew) version ships with an MCP server • Sound files, templates, and other configuration files are repo-friendly JSON files • Export: WAV at 44.1 / 22 / 11 kHz and 16 / 8-bit, plus per-layer stem export for your DAW or game engine.
Make some noise!







