STEMEKI – stems · loops · remix

🇬🇧 English · 🇭🇺 Magyar

▶ Website: ekidio.github.io/stemeki · ⬇ Download: latest release (DMG)

STEMEKI splits any song into stems, locks it to a bar-exact beat grid, lets you rebuild its structure like a mini DAW, and exports DAW-ready loops: bar-exact, on a whole BPM, ready to drop into any session.

It's a native macOS app (Swift, Apple Silicon). Separation runs locally with Demucs 4 on the Apple GPU – your music never leaves your Mac.

STEMEKI is an EKIDIO SOUND app. See also: PADEKI · DAWEKI V3.

Why it's different

Most stem splitters stop at "here are four files". STEMEKI goes on:

• Smart Tempo. A trained beat model (Beat This!) listens to the whole mix and finds every beat and the 1, like DJ apps and Logic do. Each beat is moved onto its real attack, and wherever the song keeps one tempo the grid is one perfectly straight line on a round BPM; where it really speeds up or slows down, the grid follows section by section.
• CUE = bar 1. The CUE lands on the song's first downbeat. Press C at the playhead (also while playing) or drag the flag to make any beat the "one".
• Rebuild the song. In EDIT mode drag a selection, click to cut, D to duplicate, drag pieces around, trim their edges. Pieces overwrite what they cover, like in a DAW.
• Export the structure, not only the song. Draw regions on the lanes in EXPORT mode and save each one as its own loop.

Features

Load and prepare

• Drop WAV, AIFF, MP3, M4A or FLAC. The song plays at once while the AI separates it; an animated screen shows the progress.
• MIX / 2 STEMS / 4 STEMS views: the whole song as one waveform, vocals + instrumental, or vocals, drums, bass and instruments.
• Precise BPM and key (with Camelot code) detection.

Beat grid

• AUTO WARP pins every beat to its hit; RESET goes back to the detection.
• CUE HERE (C), draggable CUE flag, NUDGE the music against the grid by ½ beat, 1 beat, ½ bar or 1 bar.
• CLICK metronome: the same bright tick on every beat, with volume and fine timing by ear (right-click).
• Export tempo: loops are stretched to exactly this BPM (pitch kept), or keep the song's own.

Edit (EDIT mode)

• Drag = select, click inside = cut, D = duplicate (an uncut selection is cut first), ⌥-drag = copy, ⌫ = delete (silence), ⌘Z / ⇧⌘Z = undo / redo.
• Selection and edges snap to the grid by zoom: bars, beats, and closer in 1/8 and 1/16 lines. Trim pieces at their edges.
• ⌘C / ⌘V: copy the selected pieces (or the audio under a selection), click where it should go (a ⌘V marker appears), paste. Pasting again lines up the next copy right after.
• U: the loop takes the start and end of the selected piece or region and follows it when you move or trim it.
• Drag pieces past the end of the song: the timeline grows with them, for a longer mix (FROM CUE exports it all).
• Fades: drag the small square on a piece's top corner inward for a fade-in / fade-out (double-click removes it). Playback, the loop and every export follow it.
• RESET on every lane brings back the freshly separated stem.

Projects

• File → Save Project (⌘S) writes Title.stemeki: the stems, edits, fades, regions, grid, CUE, loop and lane levels. Reopen it with Open Project (⇧⌘O), a double-click or by dropping it on the window: ready at once, no new separation.
• A dot in the song list marks unsaved changes; quitting asks before anything is lost.

Export (EXPORT mode)

Button	What it saves	Tempo	Edits
FULL	the marked lanes as they are, the whole file	original	no
FROM CUE	from bar 1 to the end – stack them in a DAW from bar 1	export BPM	yes
LOOP	the loop range, bar-exact	export BPM	yes
REGIONS	every region on the marked lanes, one file each	export BPM	yes

• EXPORT… opens all four exports side by side, each with a picture of what goes into the file, what tempo it gets and an example file name. LOOP works only with the loop on, REGIONS only when there are regions.
• Marking a lane off for export also mutes it: you hear what you export.
• Files keep the original format (WAV / AIFF / FLAC, bit depth, sample rate). WAV loops carry ACID and smpl data (tempo, beats, root, loop points) and a "Made with STEMEKI" note.
• Every export asks for a folder. Names: Title_DRUMS_127bpm_REGION_17_20.wav.

Preparing	First-run intro

Keyboard

Key	Action
Space	play / pause
Enter	to the start (the view follows with FOLLOW on)
L	loop on / off
K	metronome on / off
C	CUE to the playhead
E	EDIT / EXPORT
D	duplicate the selection
U	loop the selection (the loop follows it)
⌘C / ⌘V	copy / paste at the clicked spot
⌘S / ⇧⌘S	save project / save as
⇧⌘O	open project
⌫	delete the selection
Esc	clear the selection
[ / ]	NUDGE the music earlier / later
⌘Z / ⇧⌘Z	undo / redo
⌘E / ⇧⌘E	export LOOP / REGIONS

Requirements

• A Mac with Apple Silicon, macOS 14 or later.
• Nothing else. At the first start STEMEKI offers INSTALL ENGINE: one click downloads its own AI engine (Python + Demucs 4 + the model, about 300 MB, 1 GB on disk) into ~/Library/Application Support/STEMEKI. No Terminal, no Python knowledge needed.
• Already have Python 3.10+ with demucs librosa soundfile? STEMEKI finds and uses it (pyenv, Homebrew or the system Python), no setup needed.

Install

1. Download the DMG from the latest release and drag STEMEKI into Applications.
2. The first time, macOS may block it: click Done, then System Settings → Privacy & Security → Open Anyway.
3. Updates arrive by themselves (Sparkle); you can also use STEMEKI → Check for Updates….

Build from source

./build.sh --install     # builds dist/STEMEKI.app and copies it to ~/Applications
./make-dmg.sh            # dist/STEMEKI-<version>.dmg
./make-release.sh        # DMG + signed appcast for a GitHub release

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© 2026 EKIDIO SOUND. Separation by Demucs (MIT), beats by Beat This! (JKU Linz, MIT).