← Playground

Stem separation

Split a song into vocals, drums, bass and everything else, with Demucs.

This tool ran on a GPU at my place, and it's been offline since I moved to New York. Below is how it worked. The engineering behind all of them is in austn.net's GPU tools.

model
Demucs (htdemucs, htdemucs_ft) on ComfyUI
The stem separation page when it was live.
The stem separation page when it was live.

Upload a song and get back four tracks: vocals, drums, bass, and everything else. Good for karaoke, remixes, or hearing what's buried in a mix.

How it worked

  • Two Demucs models to choose from: the standard one, and a fine-tuned version that's slower but cleaner.
  • Uploads are checked for size and type before they're read, stored, and handed to the job by id.
  • Separation is the slowest tool on the site, up to about fifteen minutes for a long track. That's the job that exposed the GPU lock expiring too early. Each tool now holds the lock for longer than its longest run.
  • Each stem downloads on its own, or all four as a zip.