Beta 1.0  Phasemap  ·  free and open source

See where your mix cancels.

Phasemap shows the phase of every frequency band, so you see exactly what disappears when your mix is played in mono. It measures loudness after EBU R128 while you work.

Download Phasemap Source code
  • VST3
  • AU
  • CLAP
  • LV2
  • Standalone
  • macOS
  • Windows
  • Linux
Phase per band · 20 Hz – 20 kHz · 1/6 octave Low End
The Phasemap window: spectrum display, loudness column, correlation meter, goniometer and switches.
How to read it

Centre is safe. The edge is gone in mono.

In Phase mode every horizontal bar is one frequency band, 20 Hz at the bottom and 20 kHz at the top. A bar's width tells you how far that band is from perfect phase, no matter how loud it is.

Phase display of a clean mix: thin green bars along the centre line.
A healthy mix. Thin green bars on the centre line: everything survives the mono sum.
Phase display with wide red bars below 200 Hz and the Low End lamp lit.
Same song, bass flipped in one channel. Everything below 200 Hz spreads to the edge in red, and the Low End lamp blinks: in mono, the bass is gone.
+1Centre. Identical in both channels, plays fully in mono.
+0.3 … +1Green. Stable stereo.
0 … +0.3Yellow. Wide; partly lost in mono.
below 0Red. Cancels when summed.
−1Edge. Fully out of phase, silent in mono.
Features

Everything at the end of the channel, in one window.

Energy mode: orange bars to the left and right of the centre per band.

Energy per band

The level of L to the left and R to the right, per frequency band. A lopsided shape shows which part of the mix leans to one side.

Loudness column with Momentary and Short-term bars, Integrated, Range and True Peak.

Loudness after EBU R128

Momentary, short-term, integrated, loudness range and true peak, with a target line for the platform you deliver to.

Goniometer showing a wide horizontal trace when the bass is out of phase.

Goniometer and balance

The classic picture of the stereo field and the overall L/R level difference, next to the band details.

Correlation meter as a row of LEDs with a white marker at the lowest value.

Correlation with memory

The overall correlation as LEDs. A white marker holds the lowest value for as long as you set, in milliseconds.

An explanation box below the Phase button.

Help where you look

Rest the mouse on any control for three seconds and a short explanation fades in. No manual needed.

Settings panel with resolution, window size and loudness targets.

Sized for your screen

Drag the window from 50 % to 400 %, or fit it to a second monitor. Mono button to listen to the sum, Freeze to stop the display.

Loudness targets

Know when the master is ready.

Choose where your music is going. Integrated turns green on target, yellow when too quiet and red when too loud. True peak turns red above the limit.

Your own targets are saved for every project. The target travels with the session, so a mix opened on another computer still shows the right goal.

TargetIntegratedTrue peak
EBU R128 (broadcast, Europe)−23 LUFS−1 dBTP
ATSC A/85 (broadcast, US)−24 LUFS−2 dBTP
YouTube, Spotify, TIDAL, Amazon, SoundCloud−14 LUFS−1 dBTP
Spotify Loud−11 LUFS−1 dBTP
Deezer−15 LUFS−1 dBTP
Apple Music, Apple Podcasts−16 LUFS−1 dBTP
AES streaming, speech−18 LUFS−1 dBTP

Checked against the EBU test signals

Every build is measured with the reference cases from EBU Tech 3341 and 3342 at 44.1 to 192 kHz. A few of the results at 48 kHz:

Test signalExpectedPhasemapResult
1 kHz sine, −23 dBFS, stereo−23.0 LUFS−22.99pass
−36 / −23 / −36 dBFS (relative gate)−23.0 LUFS−23.01pass
−72 / −36 / −23 / −36 / −72 dBFS (both gates)−23.0 LUFS−23.01pass
20 s at −20, then −30 dBFS10 LU range10.0pass
Sine at fs/4, samples at −3 dB0.0 dBTP+0.11pass

Tolerance ±0.1 LU for loudness, +0.2 / −0.4 dB for true peak, as specified by the EBU.

Open source

Read it. Check it. Make it better.

Phasemap is free software under the GPLv3. You can read how every number is calculated, build it yourself and send improvements.

src/dspThe measurements. No user interface, fully tested.
src/pluginParameters, project state, audio routing.
src/uiThe window, drawn entirely in code.
testsEBU cases, phase cases, every sample rate and block size.
GitHub repository How to contribute 
# build and test it yourself (CMake 3.22+, C++17)
git clone https://github.com/nullzone-audio/phasemap.git
cd phasemap
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build --config Release
ctest --test-dir build -C Release

# 100% tests passed, 0 tests failed out of 3

Good first contributions: a new loudness target, a clearer help text, a translation, or testing Phasemap in your DAW and reporting what you find.

How it started

Made for one studio. Open for everyone.

Phasemap began in October 2026 in a small studio in northern Germany. Leon Tassoulis wanted a meter for his own mixes that shows more than one correlation number: where in the spectrum a mix cancels in mono, and how loud it really is.

The first version was a private plugin for his own sessions in Logic. It worked well enough that it deserved more people, so it became Phasemap: free, open source and built to be improved together. Leon had never written a plugin before.

Designed by a human, built with AI. Leon designed the interface and the way Phasemap works, by hand, from his own sessions, and decides what goes in. The code was written with Claude, an AI assistant by Anthropic. The numbers do not rely on either of them: every measurement is checked against the published EBU test signals, automatically, on every build.

Thank you to everyone who tests it, reports a bug, writes code, translates a help text or simply tells a friend. Every improvement goes into the next version and is credited in the release notes.

Support

Free forever. Built together.

Phasemap costs nothing and has no account, no licence key and no tracking.

Report a problem

Open an issue on GitHub with your DAW, system, plugin format and a screenshot. English or German both work.

Open an issue

Ask a question

Not sure what a display means, or how to install on your system? Check the answers below, or start a discussion.

Join the discussion

Contribute

Fix a bug, add a feature, improve the design. The architecture guide explains the code in ten minutes.

Read the architecture guide

Support the project

Star the repository, tell other engineers about it, or share a mix where it helped. Donations open soon.

Star on GitHub
Download

Pick your system.

Phasemap Beta 1.0 comes with an installer for each system, on the GitHub releases page. Run it, then rescan plugins in your DAW. It is a beta: if anything looks wrong, please tell us.

macOS

  • Installer: .pkg
  • AU, VST3, CLAP to /Library/Audio/Plug-Ins
  • Standalone app to /Applications

Apple Silicon and Intel, macOS 10.13 or newer.

Windows

  • Installer: Setup.exe
  • VST3, CLAP to C:\Program Files\Common Files
  • Standalone app to C:\Program Files

Windows 10 or 11, 64-bit.

Linux

  • Archive: .tar.gz, unpack and run ./install.sh
  • VST3, CLAP, LV2 to ~/.vst3, ~/.clap, ~/.lv2

Built on Ubuntu 22.04, x86-64.

Go to the releases
Versions

Beta 1.0 is out.

Phasemap is in public beta. Versions are named Beta 1.0, Beta 1.1 and so on, until the first stable release, Phasemap 1.0. Everything that changes is listed here and in the changelog on GitHub.

  1. Beta 1.0October 2026

    First public version.

    • Phase and energy per frequency band, Low End lamp
    • Loudness after EBU R128 with built-in and own targets
    • Correlation meter with hold, goniometer, balance, Mono, Freeze
    • Hover help, scalable window up to 4K
    • VST3, AU, CLAP, LV2 and standalone for macOS, Windows and Linux
Questions

Good to know.

My system warns me about the installer.

The installers are not yet signed with a paid developer certificate, so your system asks once whether you trust them. The code is open, and every installer is built automatically on GitHub from that code.

macOS: if the .pkg "cannot be opened", go to System Settings → Privacy & Security, scroll down and click Open Anyway. Windows: if SmartScreen says "Windows protected your PC", click More info → Run anyway.

How do I remove Phasemap?

macOS: delete Phasemap.component, Phasemap.vst3 and Phasemap.clap from the folders under /Library/Audio/Plug-Ins, and the app. Windows: Settings → Apps → Phasemap → Uninstall. Linux: run ./uninstall.sh from the unpacked folder.

Does Phasemap change my audio?

No. Audio passes through bit for bit, with no latency. Only the Mono button changes what you hear, by summing L and R for as long as it is on.

Which DAWs work?

Any host that loads VST3, AU, CLAP or LV2: Logic Pro, Ableton Live, Cubase, Reaper, Bitwig, Studio One, FL Studio, DaVinci Resolve (Fairlight, VST3) and more, on mono and stereo tracks at any sample rate. Pro Tools needs the AAX format, which Phasemap does not offer yet.

Why does Integrated keep running when the window is closed?

Loudness is measured in the audio engine, so a whole song or episode is measured even if you never open the window. Press Reset, or turn on "Reset Integrated when playback starts" in the settings.

Where are the settings?

Click the word PHASEMAP in the top right corner of the plugin: band resolution, window size, loudness targets and your own saved targets.

Is it really free? What is the catch?

There is none. Phasemap is GPLv3 open source and will stay free. Nullzone Audio is a small open project; if it helps you, the best payment is a bug report, a contribution or telling a friend.