Prism — Real-time Audio Analysis & Metering

// Analysis

Eight analyzers. One engine.

Build a rack around the signal, not the other way around. Every analyzer is independently configurable, resizable, rotatable where supported, and available across Prism’s desktop, plugin, and terminal surfaces.

01 / FFT

Spectrum Analyzer

Calibrated spectra and pitch readouts, with reference-track overlays, difference views, and level matching.

02 / Time

Oscilloscope

Stable time-domain views with fundamental-frequency pitch locking and sub-sample triggering.

03 / Phase

Vectorscope

XY, Polar, and M/S Linear stereo analysis with calibrated references and optional multiband RGB.

04 / Spectrum History

Waterfall

Watch spectra unfold over 1–30 seconds, with adjustable ridge density and theme or heat colors.

05 / Time × Frequency

Spectrogram

Classic and frequency-reassigned views across Log, Mel, and Linear scales with stereo-energy analysis.

06 / Ballistics

VU Meter

300 ms metering, adjustable 0 VU calibration, stereo correlation, and needle or bar displays.

07 / Loudness

Loudness Meter

ITU-R BS.1770 momentary, short-term, and integrated LUFS with true-peak activity.

08 / History

Waveform

Scrolling mono or stereo history with transient-preserving sampling and optional multiband energy.

// Hosts

Desktop, plugin, and terminal.

Each host is built around the same native analysis implementations where applicable. The interface changes; the analyzer vocabulary and calibration do not.

Desktop / Windows · macOS · Linux

System and device capture

Prism captures the active system output without a virtual audio cable, or switches to a microphone, interface, or line input. Scopes can remain in the rack or run as independent popout windows.

macOS: CoreAudio Audio Hardware Taps
Windows: WASAPI loopback capture
Linux: PulseAudio monitor sources; U8, S16, S24, S32, and F32 input normalization
Device inputs: Separate low-latency AudioWorklet capture path
Channel routing: Independent Left/Right routing, live channel activity, and saved routes per source
Clocking: Analysis follows the active device sample rate

DAW / VST3 · AU · CLAP

One plugin per analyzer

Use any of the eight analyzers inside your DAW, or send a track or bus to the standalone app with Prism Bridge. Your audio passes through unchanged.

Formats: VST3 and CLAP on Windows, macOS, and Linux; AU on macOS
RT callback: Copies samples into a lock-free FIFO
Analysis: FFT, loudness, and rendering work happens outside the real-time audio thread
Signal path: Pure pass-through; host audio remains unmodified
State: Scope configuration serialized into project/plugin state
Bridge timing: DAW-synced Bars + Beats or Seconds rulers in Waveform and Spectrogram

Terminal / prism-tui

Native terminal interface

prism-tui uses the same analyzer and system-capture implementations in a keyboard-driven interface with live output switching, input trim, profiles, and .iro themes.

Rendering: 60 FPS default; experimental 120 FPS mode
Compatibility: 256-color mode up to 60 FPS; basic ANSI safe mode up to 30 FPS
Analysis: All eight scopes, including Waterfall, reassigned spectrogram, and multiband modes
Memory: Approximately 35 MB in typical use

05sec10sec30sec60sec

// Rolling capture

Forgot to record that? Prism didn't.

Keep the last 5–60 seconds of audio ready to drag out as a WAV. No need to start recording beforehand.

Source rates to 384 kHz16-bit PCM · 32-bit floatDirect file drag-out

// Customize

Profiles, themes, and display modes.

Prism’s neutral dark interface is the starting point, not a locked identity. Save entire workspaces as profiles and change the application and every analyzer through editable theme files.

Prism v0.3 neutral dark interface with Spectrum, Oscilloscope, and Vectorscope settings open

.prsm

Profiles

Save visible scopes, rack layout, analyzer settings, window state, and popout positions as a shareable workspace.

.iro

Themes

Edit interface, control, scope, gradient, guide, label, meter, and overlay colors in a human-readable theme file.

WINDOW

Overlays and docking

Pin scopes above your apps with solid, blurred, or clear backgrounds. On Windows, dock the rack and reserve its screen space.

// Streaming

Chroma-ready when you need it.

Built-in chroma themes make it easy to key Prism’s scopes into OBS and other video workflows as clean overlays.

Prism scopes rendered against white and blue chroma backgrounds

// Technical

Pretty graphs. Serious numbers.

Prism’s visual surfaces share native analysis implementations, tested calibration behavior, and a signal path designed to keep expensive work away from real-time audio callbacks.

AnalysisNative C++ DSP shared across desktop, plugins, and terminal where applicable

SpectrumCalibrated dBFS magnitude, 1024–16384 FFT, Log/Mel/Linear scales

LoudnessITU-R BS.1770 momentary, short-term, integrated LUFS, and true peak

CaptureCoreAudio taps, WASAPI loopback, PulseAudio monitors, and device input

PluginsVST3 and CLAP on all three platforms; AU on macOS; mono and stereo

MeasurementInteractive measurement overlays, with Linked Analysis sharing compatible guides across desktop scopes

Rendering10, 30, 60, 120, or 144 FPS, plus display-synchronized rendering

Latency~7 ms median capture-to-render — default rack, M5 Pro, 120 FPS; excludes display latency. Methodology ↗

PlatformsWindows · macOS · Linux

LicenseGNU General Public License v3.0

// Download

Put Prism where you work.

Free and open source, with DAW plugins and prism-tui included where supported. The Linux AppImage is desktop-only.

All releases ↗

⊞

Windows

Desktop · VST3 · CLAP · TUI

Installer (.exe) ⌘

macOS

Desktop · VST3 · AU · CLAP · TUI

Installer (.pkg) ›_

Linux

Desktop · Plugins + TUI by package

AppImage · DEB · RPM · TAR.GZ

Build from sourcebash

git clone https://github.com/Boof2015/prism.git
cd prism
npm install          # builds the native module
npm run dev          # desktop development
npm run dist:mac     # or dist:win / dist:linux