Master Audio
Master Audio cover: the app logo and the words Master Audio, audio editor for macOS, multitrack, effects, on-device AI, over a green waveform

Master Audio Software · free for macOS

Edit audio like text.

A simple audio editor with a real multitrack mode, transcription you can edit with, stem separation and AI voice cleanup. Everything runs on your Mac, and your audio never leaves your computer.

Version 0.87 RC2 · macOS 11+ · Apple Silicon · 20 MB · PDF manual included

Windows version in the works

Speech

Click a word, select the sound

Master Audio transcribes your recording with Whisper, right on your Mac. The text and the waveform are linked: select words in the transcript and the matching audio is selected, ready to play, cut, copy or send to the multitrack.

A transcript that edits your audio

  • Click a word to select it in the waveform. Drag or Shift-click to select a whole sentence
  • Select in the waveform and the words light up in the transcript
  • Play, copy, delete or open the selection in a new file, or send it to the multitrack
  • Effects and the volume bar work on the selected words only
  • Save the transcript as text or as subtitles (.srt)
Transcript window with a sentence highlighted and the matching part of the waveform selected
The selected sentence is selected in the waveform too.

Translate it into another language

Translate the transcript and show the original, the translation, or both lines together. Save both as one text file to share with a translator or a co-host.

Transcript window showing each English sentence with its French translation underneath
English transcript with its French translation.

Master AI Tools

Split any song into four stems

Music source separation with Demucs pulls a song apart into vocals, drums, bass and everything else. Remix a track, build a karaoke version or study a bass line.

One click, four tracks

  • Four new files, each with its own icon: microphone, drum kit, bass guitar and keyboard
  • Tick one box and the stems land in a new multitrack session, lined up and ready to mix
  • Mute, solo or rebalance each stem with its own volume and pan
Music Source Separation (Demucs) window with Vocals, Drums, Bass and Other
Multitrack session with four tracks named Vocals, Drums, Bass and Other
The four stems of a three-minute song in a new multitrack session.

Voice cleanup

Clean voices, without the cloud

Three neural tools for podcasts, interviews and voice-overs. Each one shows the waveform before (grey) and after (blue) and lets you hear the result before you apply it.

Background Noise Removal window using RNNoise

Background noise removal

A built-in neural network (RNNoise) removes hiss, hum, traffic and fans while keeping the voice.

Speech Enhancement window

Speech enhancement

Neural noise removal, then a rumble filter and level adjustment for clear, even speech.

Voice Isolation (Apple) window

Voice isolation

Apple's on-device neural network keeps the voice and removes music, noise and room sound.

Cut the silences automatically

Voice activity detection with Silero finds where someone speaks. Tune the sensitivity, the shortest silence, the shortest speech and how much air to keep around each phrase.

  • Mark the silences, or delete them all at once
  • Make a trimmed copy and open it in the editor, add it to the multitrack or save it
Voice Activity Detection (Silero) window reporting 21 silences found, 13.6 seconds or 26 percent
21 silences found: 13.6 s, or 26 % of the recording.

Editing

A real multitrack, and a fast editor

Switch between the waveform editor and the multitrack with one click. Open files stay in the left panel, ready to move between the two.

Multitrack

  • Fade handles on every clip corner
  • Automatic crossfade where two clips overlap
  • Volume envelopes with keyframes: ⌥-click to add one, drag to adjust
  • Trim by dragging clip edges, or with Q and W at the playhead
  • Reorder tracks by drag and drop, with volume, pan, mute and solo
  • Non-destructive: your original files are never changed
  • Drag files from the side panel straight onto a track; right-click a clip to duplicate it or copy it to a new file
  • Sessions in .sesx format, compatible with Adobe Audition. Export the mix, or each track as its own file
Multitrack with five tracks showing crossfades, fade handles and volume keyframes
Crossfades, fades and volume keyframes across five tracks.

Waveform editor

  • Cut, copy, paste, crop, undo and redo, with a gain slider right on the selection
  • Right-click a selection to copy it to a new file, save it, open it in the multitrack, transcribe it, translate it or detect speech
  • Editor shortcuts: I / O for in and out, J K L for shuttle playback
  • Undo history in the Edit menu: jump straight back to any earlier step
  • Loop playback, peak meter, export to WAV, MP3 or OGG
Waveform editor with a selection and its right-click menu
Everything you can do with a selection, one right-click away.

Effects

Effects you hear before you apply them

Every effect window has real-time preview, a preview of the processed waveform, and a loop button that replays the selection while you adjust. Audio Unit plugins open with the same preview, waveform and loop buttons.

EQ and filters

  • 11-band and 31-band EQ
  • Parametric EQ
  • N-band EQ
  • High-pass and low-pass

Delay and modulation

  • Delay
  • Flanger
  • Chorus
  • Reverb
  • Vibrato

Dynamics

  • Compressor
  • Expander
  • Limiter and hard limiter
  • Noise gate
  • Multiband compressor

Time, pitch and level

  • Change speed
  • Time stretch
  • Pitch shift
  • Normalize
  • Remove DC offset

Your installed Audio Unit and VST plugins show up in the Effects menu too. The Generate menu makes white, pink and brown noise, tones, sweeps and DTMF.

Download

Get Master Audio for Mac

Free. Open the disk image and drag Master Audio onto the Applications shortcut. The illustrated PDF manual is in the disk image too.

Download for macOS

The app is not notarized by Apple yet. If macOS blocks it the first time, open System Settings, then Privacy & Security, and click Open Anyway.

Details

Version
0.87 RC2
System
macOS 11 Big Sur or later
Processor
Apple Silicon (M1 or later)
Size
20 MB (disk image)
Manual
PDF, included
Updates
Checked at launch, or with File › Check for Updates
Price
Free
Windows version in the works

A Windows version is being prepared. Write to me if you want to hear when it is ready.

Support

Buy me a coffee

Master Audio is made by one person. If the app is useful to you, a small tip helps me keep adding features and fixing bugs.

☕ Buy me a coffee

Contact

A question, a bug, an idea?

Write to me. I read every message.