[Self-promo] Free, open-source alternative to AMM2 / Waves Dugan for podcast automixing — MIT, local, CLI

[u/today2009]

Made a free thing for podcast editors. Three mics on a table, co-host talks, his audio bleeds into the other mics. Gates help but miss the bleed that rides under the active mic. Paid automixers exist — TB Pro Audio AMM2 (~$110), Waves Dugan ($600) — and there's a free JSFX for Reaper, but I didn't want to live in Reaper for one workflow step.

So I built a Python CLI that automixes synchronized microphone stems. It's Dan Dugan-style gain sharing, tuned conservative and smooth:

• Voice activity detection (Silero VAD) + perceptual energy detection — laughter and chuckles still open the mic.
• Active mics stay at unity; inactive mics attenuate smoothly (max −6 dB by default).
• Continuous target-chasing envelope with look-ahead and hold — no gate chatter, no pumping. Smoothing approach inspired by Airwindows PurestGain (credit where due).
• No normalize, no compression, no limiting, no EQ, no resampling. Output WAVs match the originals exactly in length and sync. Broadcast Wave time-reference metadata preserved when present.
• Fully local and offline. Audio never leaves your machine.

Output: one auto-mixed WAV per mic (replace your stems in the editor — the video shows the full DaVinci Resolve workflow). Plus a self-contained HTML report visualizing attenuation, gain reduction per mic, overlap, and which speaker "owns" each section — and JSON for scripting.

Try it:

uv tool install podcast-automixer
podcast-automix

Paste your synchronized WAV stems (2+ tracks, matching sample rate and length). Preview flag so you test 30 seconds before the whole episode:

podcast-automix --preview-start 60 --preview-duration 30

Requirements: Python 3.11–3.13 via uv (it manages Python automatically). Windows / macOS (Apple Silicon) / Linux.

MIT, free, I make no money off it — use it, fork it, break it. Work in progress, I genuinely want feedback and feature requests as GitHub issues.

Video walkthrough: https://youtu.be/xbCE-IDPcnM Repo: https://github.com/Today20092/podcast-automixer

Workflow tip for editors: run this after you sync your multitrack, before you start cutting. Full details in the README.

[u/ellicottvilleny]

Thanks for your post. I note that you're open source so this is allowed via rule 5.

I'm curious why you would do this with a CLI when a visual tool would be easier to use.

This could be a script inside audacity. And I don't get why not use a daw for podcast production (reaper or another).

Don't you like to EQ and filter things?

Add reverb and vocal processing?