Stem Splitter

Sampling from a full mix means fighting the vocals. Stem Splitter pulls a song apart into drums, bass, vocals and everything else, on this device, so you can sample the part you want. The 6-Stem Splitter Pack adds guitar and piano.

Stem Splitter is part of Pro, and the 14-day trial includes it. It runs on macOS, Windows and Linux, and from version 1.6 on 64-bit Android phones with about 6 GB of memory or more. It is coming to iPhone and iPad with version 1.6. I built it for sampling rather than mastering, so results vary from song to song.

Get a Splitter Pack

The Stem Splitter downloads a splitter pack from its original public source after you’ve read and accepted its licence. I don’t host, sell or bundle the files. You can also add a compatible pack file you already have (a Demucs-format file).

The first time you open Stem Splitter, it asks you to download a splitter pack. You only do this once for each pack.

Open Stem Splitter.
Pick a pack from Splitter Pack:
- 4-Stem Splitter Pack (Fast), 166 MB: drums, bass, vocals and everything else, with a quicker split. The usual choice where it’s available (Macs with Apple silicon, Windows and phones and tablets).
- 4-Stem Splitter Pack, 84 MB: the same four parts, on every computer.
- 6-Stem Splitter Pack, 55 MB: adds guitar and piano stems. Slower, and results vary more on full mixes. Computers only.
Read the pack’s licence, then tick I have read and accept this splitter pack’s licence.
Select Download followed by the pack’s name, for example Download 4-Stem Splitter Pack.

The app checks each file before it installs it. After that, splitting runs on this device and works offline. Your audio is never uploaded. On mobile data, the first download asks before it starts.

To download another pack later, open Download Splitter Packs at the top of Stem Splitter. To remove one, use the bin button next to it (Remove this pack). With more than one pack installed, pick the one to use in that list.

Split a Song

Choose a song: select Browse for an Audio File, drag a file onto Stem Splitter or select Choose from Library. WAV, MP3, FLAC, AIFF, OGG and M4A files all work. If the Sample Editor has one sample loaded, Use Current Editor Sample brings that in.
To split just part of the song, drag the markers on the waveform. Select at least one second. Preview Selection plays it. With the markers at the ends, the whole song is split.
Choose the Bit Depth: 16-bit (the default, and a third smaller) or 24-bit. EP devices accept both.
Select Extract Stems (Extract Stems from Selection if you’ve made one).

A full song usually takes one to a few minutes on a computer, and longer on a phone or tablet. On a computer you can keep using the app while it runs: Stem Splitter carries on in the background and tells you when the stems are ready. On a phone or tablet, keep the app open while it splits (the screen stays on). If you leave the app part way through, it tells you the next time you open it.

Use the Stems

When the split finishes, you see Stems Ready with a row for each stem.

Play All Stems plays them together. Use the mute and solo buttons to hear one part or a mix.
Play one stem on its own with its play button.
Preview the stems, then select Save to Library to keep them. They go into your sample library as a pack called “(song name) Stems”. Until you save, the stems only last for this session.
Create Instrumental mixes everything except the vocals. Once you’ve saved, it’s added to the pack. Before that, you save it as a WAV file.
Open in the Sample Editor sends a stem to the editor to trim, chop and upload.
The … menu on a stem has Send to Batch Processor and Export as WAV.

After you save, you can tick several stems and use Send Selected to Batch Processor, or export the whole pack with Export Pack as ZIP.

To try again, select Split This Song Again (for example with a different selection), or Choose a Different Song.

From the Sample Editor

The Extract Stems button in the Sample Editor’s toolbar opens Stem Splitter. If the editor has one sample loaded, select Use Current Editor Sample to split it.

Add a Pack File

If you already have a compatible splitter pack file, you can add it instead of downloading one.

Select Add a Pack File (on the setup screen or under Download Splitter Packs), or Add Another Pack below the list of installed packs.
In the Add a Pack File dialog, confirm you have the rights to use the file, select Choose a Pack File and pick it.

The app takes Demucs-format .bin files, the same kind it downloads for the 4-Stem and 6-Stem Splitter Packs. The Fast pack can only be downloaded. Adding a 4-stem file replaces your 4-Stem Splitter Pack, and a 6-stem file replaces your 6-Stem Splitter Pack. The app checks the file before installing it. If it can’t use a file, it tells you why: it isn’t a pack it recognises, it’s incomplete or it’s a type the app can’t run yet.

Troubleshooting

Stem Splitter isn’t there: on a phone or tablet it needs version 1.6 or later and a device with about 6 GB of memory or more (on Android, a 64-bit phone). On a computer, reinstall EP-PatchStudio from the download page, and email me if it’s still missing.
A download fails or stops: the Pack Download notification says why:
- “Not enough disk space. This download needs (size) MB free.”
- “Download failed: … Try again.” or “Download interrupted: … Try again.”
- “Download stopped before the splitter pack was complete. Try again.”
- “Downloaded splitter pack failed checksum verification. Try again.”
- “Download cancelled. Partial download removed.”
Check your connection and disk space, then try again. A failed or cancelled download is removed, so nothing half-finished is left behind.
“Separation Failed”: select Show Error Details to see what happened, then Retry or choose a different file. If it keeps happening, send me the diagnostic logs.
Long songs: Stem Splitter can split up to 15 minutes at a time. Drag the markers to select 15 minutes or less, or trim the audio first. On long tracks Play All Stems is turned off to save memory. Opening a stem in the editor, batch processing and export still work.