Introducing Litmus by Candela Audio - an internal plugin host that lives right in your mix chain and acts as an objective second set of ears for every decision you make. Instead of being just an analyzer, Litmus automatically gain‑stages your processing, lets you hear exactly what each plugin is doing, and helps you choose settings and tools based on evidence, not guesswork.
Insert Litmus on a track or bus, load your favourite VST3 or AU processors inside it, and mix as normal – compression, EQ, saturation, clipping, whatever you like. Litmus constantly matches loudness in the background using ITU‑R BS.1770‑4 LUFS, so every tweak you make is instantly level‑matched, forcing you to judge tone, punch and clarity instead of being fooled by "louder is better."
Whenever you want to zoom in, delta monitoring lets you solo the exact sonic footprint of a plugin or chain – the added harmonics from a saturator, the "air" an EQ boosts, or the transient changes from a compressor – so you can really learn what each tool contributes to your sound. When it's time to commit, blind A/B mode anonymises chains, plugins or dry vs wet, tracks your votes, and reveals the winner only at the end, helping you pick the best‑sounding option without brand or UI bias.
Back up your ears with Litmus’s built‑in spectral, harmonic, phase and loudness analysis, then collapse it back down and keep mixing – it's designed as an everyday utility that stays in your template, not a one‑off lab tool. Built with automatic latency compensation and crash‑safe scanning, Litmus runs as a VST3 (Win/macOS/Linux) and AU (macOS) effect and hosts your VST3/AU processors inside a single managed chain, with one license covering all formats and platforms.
Videos
Overview video:
Short demo:
Price & demo
Launch price: $39 (for a limited time)
Free 14‑day fully functional demo available.
Links
Product page: https://candelaaudio.com/litmus
Download page: https://candelaaudio.com/download
Key features
- Internal VST3/AU plugin host with up to 8 slots per chain (VST3 on Win/macOS/Linux, AU on macOS).
- Per‑slot Auto Gain with ITU‑R BS.1770‑4 LUFS matching, three‑phase measurement, and 100 ms smoothed gain.
- Delta monitoring with wet/dry blend, dedicated delta gain, LUFS/RMS/peak readouts, and latency‑compensated alignment.
- Blind A/B engine for Chain vs Chain, Plugin vs Plugin, and Dry vs Wet with randomized labels, crossfaded switching, and vote history.
- Analysis toolkit: 2048‑point FFT spectral comparison, harmonic analyzer (fundamental + 16 harmonics, note + THD%), phase correlation and full loudness metering (momentary, short‑term, integrated LUFS, RMS, peak).
- Automatic and FFT‑based latency detection, crash‑safe plugin scanning, sidechain support and extensive DAW automation for hosted plugins.
- Formats: VST3 (Win/macOS/Linux), AU (macOS).
- Hosts: Any VST3‑ or AU‑compatible DAW
- Audio: 32‑bit float, stereo I/O, optional stereo/mono sidechain.
- OS: Windows 10+, macOS 11+, Ubuntu 22.04+ (x86_64; Apple Silicon and Intel on macOS).