Vortessa® — Stem Recorder Guide

00 — Overview

What's in this folder

This is a separate download from the main Vortessa patch. If you haven't downloaded it yet, get it from Gumroad (it's free) and place the folder anywhere on your computer.

This folder contains everything you need to record and split Vortessa's multitrack stems. Vortessa records two multitrack files — rec1.aiff and rec2.aiff — each containing 20 independent channels, one per synthesis module. Together they give you 40 mono stems to work with in any DAW.

Vortessa_Split_Multichannels/
  rec1.aiff    ← placeholder — Browse will overwrite this
  rec2.aiff    ← placeholder — Browse will overwrite this
  vortessa_split.sh ← macOS split script
  vortessa_split.bat ← Windows split script
  README.html     ← this file

rec1.aiff and rec2.aiff are placeholder files — they must be present in the folder before you start. Do not delete or rename them. Browse will overwrite them with your recording.

The split script is smart — it automatically detects and skips silent channels. If you only activated 6 modules during your session, you get 6 stems, not 40 empty files.

Ultrasonic content: Vortessa's dissipative synthesis engines — particularly the Lorenz/Rössler attractors and the feedback networks — can generate spectral energy above 20 kHz. This is an intrinsic property of the system, not an error. Your DAW and audio interface will handle it transparently, but be aware that recorded stems may contain ultrasonic components. If you are monitoring at high volumes through tweeters sensitive above 20 kHz, consider inserting a gentle low-pass filter at the master bus.

01 — Record

Recording your session in Vortessa

The Multitrack Recorder is in the top-right corner of the Vortessa patch — look for the Browse Save and Record buttons. There are no subpatchers to open; everything is directly accessible from the main interface.

1

Open Vortessa and start your session as usual — let the system run until it reaches a state you want to capture.
2

Click Browse Save. A file dialog appears — navigate to the Vortessa_Split_Multichannels folder and select rec1.aiff. You are telling Max to overwrite that placeholder file with your recording. Do not type a new name or save to a different location.
3

Inside multimix_2: same — click Browse Save, navigate to the same folder, select rec2.aiff.
4

Flip the Record toggle to start recording simultaneously. Flip again to stop.

Always click Browse Save before hitting Record, and always select the placeholder files inside the Vortessa_Split_Multichannels folder. If you save elsewhere or use a different filename, the split script won't find the files.

About the placeholder files: when you first click Browse Save, Max immediately writes a short silent file to the selected path — this is normal behaviour. It is not your recording. Your actual session audio is written when you hit Record and stop it.

Stereo Master Recorder: Vortessa also includes a second recorder that captures the full stereo mix with the pan law already applied — ready to use without any post-processing. Use the multitrack recorder when you want full DAW control over each stem. Use the stereo master recorder when you want a single file that sounds exactly as Vortessa did during the session. Choose one before you start. Never both at the same time.

02 — Install ffmpeg

Installing ffmpeg — free, takes 2 minutes

ffmpeg is a free, open-source audio tool used by professionals worldwide. It's a small command-line utility — no GUI, no subscription, no tracking. You install it once and forget about it.

macOS — via Homebrew (recommended):

        # Step 1 — install Homebrew if you don't have it yet
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

# Step 2 — install ffmpeg
brew install ffmpeg
    

Homebrew is the standard package manager for macOS — used by millions of developers. The install takes about 2–5 minutes depending on your connection.

Windows:

        # Option A — via winget (Windows 10/11 built-in)
winget install ffmpeg

# Option B — download manually from ffmpeg.org
# → https://ffmpeg.org/download.html
# → extract the zip, add the /bin folder to your PATH
    

To verify ffmpeg is installed correctly, open Terminal (macOS) or cmd (Windows) and type ffmpeg -version. You should see version info.

03 — Split

Splitting the multitrack files

Once you have rec1.aiff and rec2.aiff recorded, run the split script. It reads both 20-channel files and exports only the active stems as individual mono WAV files.

macOS:

        # Navigate to this folder
cd /path/to/Vortessa_Stems

# Make the script executable — only needed once
chmod +x vortessa_split.sh

# Run the split
./vortessa_split.sh rec1.aiff rec2.aiff
    

macOS shortcut: open Terminal, type cd (with a space), then drag the Vortessa_Stems folder from Finder into the Terminal window. Press Enter. Then run the commands above.

Windows:

        REM Drag both .aiff files onto vortessa_split.bat
REM Or from cmd:
vortessa_split.bat rec1.aiff rec2.aiff
    

The script creates a new folder called stems_YYYYMMDD_HHMMSS next to your recordings. Example output:

Vortessa Stem Splitter
----------------------
Threshold: -60dB

Splitting mix 1 (tracks 01–20)...
✓ track_01.wav (-24.3dB)
✓ track_02.wav (-31.1dB)
— track_03 skipped (-89.0dB)
✓ track_04.wav (-18.7dB)
— track_05 skipped (-91.0dB)
— track_06 skipped (-91.0dB)
— ... (silent tracks skipped)

Done.
Saved: 8 tracks
Skipped: 32 silent tracks

The silence threshold is -60dB by default. If a module was barely active you can lower it — open the script in any text editor and change SILENCE_THRESHOLD=-60 to a lower value like -70 or -80.

04 — Import

Importing stems into your DAW

After splitting you have individual mono WAV files — track_01.wav through track_40.wav (only the active ones). Import them into any DAW:

①

Reaper / Logic / Ableton / Pro Tools: drag the entire stems_ folder into the session. All tracks land at bar 1, perfectly aligned.
②

Each file is mono — pair them as stereo if needed, or keep them separate for full spatial control.
③

Tracks are numbered sequentially — 01–20 from multimix_1, 21–40 from multimix_2. They are sample-accurate and in sync.

05 — Alternatives

Alternative methods — no Terminal required

If you prefer not to use the command line, these free tools can split the multitrack files manually:

Audacity

Free, open-source, cross-platform. Open rec1.aiff → it imports all 20 channels as separate tracks → File → Export → Export Multiple → one file per track.

audacityteam.org →

Reaper

Free to evaluate, professional DAW. Import the multitrack file → it auto-expands into individual channels → export stems directly from the session.

reaper.fm →

VLC

Free media player. Can demux multichannel audio files via Media → Convert/Save. Less precise but works for quick previews of individual channels.

videolan.org →

ocenaudio

Free, lightweight audio editor. Opens multichannel files and lets you export individual channels without setup. Simpler than Audacity.

ocenaudio.com →

The ffmpeg script is still the recommended method — it's the only one that automatically detects and skips silent channels, saving you from managing empty files manually.

06 — Troubleshooting

Common issues

?

zsh: permission denied
Run chmod +x vortessa_split.sh once before running the script.
?

ffmpeg: command not found
ffmpeg is not installed or not in PATH. Follow Step 02 above. On macOS after Homebrew install, close and reopen Terminal.
?

All 40 tracks are saved (none skipped)
Your recording has noise on silent channels — lower the threshold. Open the script and change SILENCE_THRESHOLD=-60 to -70 or -80.
?

start requested without preceding open (Max console)
You flipped the toggle before clicking open. Always click open first, wait for the dialog to close, then start recording.