ReStem 2: Drum Stem Separator

ReStem 2 is an AUv3 plugin that pulls a finished drum recording apart into the individual pieces of the kit — and it does it in real time, as the audio plays.

Insert it onto a stereo drum track or a full mix, and ReStem 2 separates it into seven stems: Kick, Snare, Hi-Hat, Toms, Ride, Crash, and Other. There is no render step and no waiting. Press play and the kit comes apart in real time.

MIDI OUT ON THE WHOLE KIT

Every stem can send MIDI in real time as it plays, so a separated recording can drive any drum instrument you already own. Toms are automatically sorted into floor, low, mid and high by pitch; hi-hats into closed, pedal and open by how long they ring. All in real-time as the track play. Every articulation has its own note assignment and its own editable split points, plus a continuous pedal-position controller for instruments that follow one

REMIX A FINISHED DRUM TRACK

Each of the seven stems gets its own channel: volume, mute, solo, a level meter and a clip indicator. Mute the ride out of a busy overhead. Bring up a buried kick. Solo the snare to hear what you are actually working with. The balance you dial in is the sound that leaves the app.

SHAPE EACH PIECE ON ITS OWN

Tap FX on any stem to open its processing:

• Noise Gate — threshold, attack, hold and release, with look-ahead, for tightening a performance and cleaning up what is left of the bleed.
• Transient Shaper — attack and sustain, so you can put the crack back into a snare or take the ring out of a tom without touching the rest of the kit.

TWO WAYS TO RUN IT

• As an Audio Unit v3 plugin inside AUM, Cubasis, Auria, GarageBand, Logic for iPad and any other AUv3 host — on a track, with your host's transport and recording.
• As a standalone app that listens to your microphone or audio interface and separates what it hears, live (ReStem has latency, so it's not suitable for live performance monitoring).

SEE THE SEPARATION

The Separation Map shows the seven stems as fields of light that move with the music, so you can watch where the energy in a performance is actually going while you mix it.

IT ALL HAPPENS ON YOUR IPAD

Nothing is uploaded. There is no account to make and no internet connection required. The neural networks that do the separation ship inside the app and run on your iPad's own GPU. Your recordings never leave the device.

BUILT ON THE DESKTOP ENGINE

ReStem 2 for iPad runs the same separation engine and the same mixing, gating, shaping and MIDI code as the desktop version of ReStem 2 for macOS and Windows. The iPad app is the real-time half of that product: it does not include the desktop's offline high-quality render modes, ARA integration, transient restoration or sample replacement.

REQUIREMENTS

iPad with an A12 chip or newer — iPad Pro (2018 and later), iPad Air (4th generation and later), iPad mini (6th generation and later), iPad (10th generation and later). Headphones are recommended when using the standalone app with the built-in microphone.

From WaveMachine Labs, makers of Auria and Drumagog.