Audio Crossfading + MIDI Multi-Mapping
Created for Maschine 3 on macOS with Maschine+ in Controller mode.
Also tested with Ableton Live. Open-source tools for performance transitions
and multi-parameter control.
Download · Maschine Setup · Ableton Live Setup · Documentation
Important
Download MK Crossfader 0.3.1 for macOS from Releases. The combined installer is Developer ID signed, Apple-notarised and stapled. Windows remains source-only. Rehearse your own project and controller before relying on the tools in a live performance.
0.4.0 XYZ Preview: release and validation limits. Adds independent X/Y/Z inputs, confirmed learning and optional Touch Gate. XYZ hardware and DAW rehearsal remain outstanding; 0.3.1 stays the stable release. See XYZ setup.
MK Crossfader began as a focused way to perform transitions from Maschine+ hardware while running Maschine 3 on a Mac. A single physical fader or knob can move several sounds or parameters together, with separate direction, range, curve, and return behaviour for each destination.
The project provides two workflows:
| MIDI Control App | Audio Crossfader VST3 |
|---|---|
| Turns one incoming MIDI CC into multiple independently shaped CC outputs. | Links one Controller instance to multiple audio Target instances. |
| Controls levels, filters, sends, effects, and other MIDI-learnable parameters. | Applies smoothed audio gain while leaving the host's mixer faders untouched. |
| Uses the host's MIDI Learn mappings; no plug-in is needed on each destination. | Runs as an audio effect on each destination; no MIDI mapping of its mixer level is needed. |
The components can be used independently. A MIDI controller that sends an assignable MIDI CC can provide the physical control: directly to the app, or through the host's parameter mapping for the VST3.
Important
Maschine+ is supported as hardware in Controller mode while Maschine 3 and MK Crossfader run on the Mac. Neither component can be installed or loaded on Maschine+ in standalone mode.
| What You Want To Do | Use |
|---|---|
| Move several mapped levels, filters, sends, or effects from one hardware control | MIDI Control App |
| Build custom parameter movements with individual ranges and curves | MIDI Control App |
| Avoid inserting a plug-in on every destination | MIDI Control App |
| Crossfade several audio paths without moving their mixer faders | Audio Crossfader VST3 |
| Keep an exact plug-in unity state at 0.0 dB | Audio Crossfader VST3 |
Use one workflow for each crossfader system. Combining them is possible when each has a separate, deliberate role.
The native macOS app receives one MIDI CC, or independent X/Y/Z inputs in the 0.4.0 preview, and sends a separate CC for every configured target through its virtual MK Crossfader MIDI port. Each target can follow side A, side B, or a custom range; XYZ additionally selects which input axis drives it.
These target types can run together. The same fader or knob can crossfade levels assigned to A and B while simultaneously moving a filter, send, effect, or other parameter through a custom Range target.
In Ableton Live, one movement can open an Auto Filter through a restricted range, raise a reverb send, reduce delay feedback in the opposite direction, and trim Utility Gain. Live stores the MIDI mappings in the Live Set; the app does not inspect the Set or read parameter values back from Live.
0.3.1 example configuration, paused for setup. A/B level targets and a filter Range target can follow the same physical fader or knob.
Version 0.3.1 also includes Performance A/B and Scene Morph built-in presets. They configure existing targets without changing MIDI assignments, names, endpoints or Return Values. Applying a preset requires paused output and confirmation; Save Current & Apply keeps a snapshot first. A/B and Range can still be combined freely. See the preset details.
Crossfade settings, presets and update checks
The same example, scrolled to Crossfade. Built-in Presets configure existing targets; saved presets keep your own configurations. Testing prereleases are optional, and update checks run only when requested.
One Controller publishes the crossfader state. Target instances receive that state and apply local smoothed gain to the audio passing through them. This keeps the host's mixer faders where you set them and lets effects placed before each Target remain part of the sound.
Controller
Controller interface, unchanged in 0.4.0. Two connected audio targets share Session 1; the Controller is halfway through a linear A-to-B crossfade.
Target
The matching Target in Slot 1 displays -6.0 dB: half amplitude at the midpoint of this linear crossfade. Other curves produce different midpoint levels.
Each Target is an audio effect. It works with samples, loops, software instruments, and live input, but it cannot process MIDI or create sound on a silent channel. A Controller on the Master or Main track distributes control data without fading that track's audio.
The VST3 controls audio gain only, with 15 ms smoothing. To move filters, sends or parameters in other plug-ins, use the MIDI Control App.
Choose the macOS release for your workflow:
- Stable 0.3.1:
download
MK-Crossfader-0.3.1.pkgfor established workflows. - XYZ Preview 0.4.0:
download
MK-Crossfader-0.4.0.pkgto test the new MIDI inputs; read its validation limits before use.
Download the matching .pkg.sha256 file with either installer. Both combined
installers require macOS 14 or later, include Apple Silicon and Intel builds,
and are Developer ID signed, Apple-notarised and stapled.
The 0.2.8 and 0.2.9 installer attachments remain withdrawn. Their release pages are historical version records, not recommended downloads.
GitHub's Source code (zip) and Source code (tar.gz) files contain source code, not installable applications or plug-ins. Developers can use the build guide; local development builds are not signed public releases. There is no Windows download at present.
The experimental Windows x64 VST3 passed the automated build and tests for 0.4.0, but has not been verified in a Windows DAW or on a physical Windows system. It remains source-only, with no Windows installer or preview archive published. The MIDI Control App remains macOS-only. See the Windows preview guide for build instructions and the host-testing checklist.
The macOS package layout is:
- MK MIDI Crossfader in
/Applications - MK Crossfader VST3 in
/Library/Audio/Plug-Ins/VST3 - the setup manual in
/Library/Application Support/MK Crossfader
If the MIDI app is running, use Return & Pause, then quit it. Close Maschine 3, Ableton Live, and other plug-in hosts before installation. Follow the installation guide for the complete process.
- Add MK Crossfader to Master and set its role to Controller.
- Map the Crossfader parameter to the physical fader through Maschine 3.
- Add a Target after the effects on every Group or Sound that should fade.
- Keep all instances in the same session and give every Target a unique slot.
- Assign each route to A, B, or Off in the Controller.
The same structure works in Ableton Live: put the Controller on Master or Main, then put a Target after the instrument, sample player, or effects on every audio path that should join the crossfade.
These steps use one input. For independent axes in 0.4.0, follow XYZ setup.
- Open MK MIDI Crossfader, leave output paused and select the physical MIDI controller. In 0.4.0, choose Single input mode.
- Press MIDI Learn and move only the intended fader or knob. In 0.4.0, check the detected channel/CC, press Use for X, then move the control again to supply a fresh value. In stable 0.3.1, learning saves the first received CC automatically; there is no confirmation button.
- Enable the virtual MK Crossfader port for MIDI mapping in the destination.
- Add a Parameter target and activate MIDI Learn on the destination control.
- Press Send Learn, then repeat for the remaining parameters.
- Assign each target to A, B, Range, or Off and configure its movement.
- Move the control once more after setup, enable Active, and test the full control range before using it in a performance.
In Ableton Live, enable Remote for the MK Crossfader input under Settings > Link, Tempo & MIDI. The app does not require Max for Live.
| Component | Requirement | Primary Use |
|---|---|---|
| MK MIDI Crossfader | macOS 14 or later; CoreMIDI destination with MIDI Learn | Maschine 3, Ableton Live, and other MIDI-learnable macOS software |
| MK Crossfader VST3 | macOS 13 or later; combined installer requires macOS 14 | Audio crossfading in Maschine 3 and Ableton Live |
| Experimental Windows VST3 source | Windows 11 x64; developer build required | Automated tests passed; DAW and physical Windows testing outstanding |
| Hardware control | Assignable MIDI CC | Maschine+ in Controller mode or another MIDI controller |
Maschine 3 and Ableton Live are currently tested on macOS. Windows DAW support remains unverified until community testing is complete. Other macOS DAWs may work if they expose standard MIDI Learn and/or support VST3, but their compatibility has not been verified yet.
The Maschine-calibrated Level target requires Maschine 3. General Parameter targets can be used with other destinations that expose controls through MIDI Learn. This project does not add Maschine 3 support for legacy hardware that Native Instruments no longer supports.
Treat MK Crossfader as performance software, not as a replacement for a recoverable mix state. Before a show, test the exact project, controller, USB path, host version, and recovery procedure you intend to use.
- Keep a manual unity or neutral recovery control available.
- A MIDI target's Return Value is the value you choose for returning a parameter when pausing; it does not remember the host's original value.
- The MIDI app cannot send configured Return Values after a crash, forced quit, or power loss.
- A VST3 Target that loses its Controller holds its last valid gain.
| Guide | Contents |
|---|---|
| Installation | Availability, installation locations, and removal |
| Maschine Setup | Controller/Target routing, MIDI Learn, and recovery |
| Ableton Live Setup | MIDI multi-control and VST3 audio crossfading |
| Windows Preview | Experimental Windows VST3 installation, testing, and reporting |
| Architecture | Component boundaries, communication, and failure behaviour |
| Privacy | Local data, update checks, and network behaviour |
| Building | Source builds and development requirements |
| Support | Public support policy and bug-report requirements |
Building on macOS requires Xcode command-line tools and CMake 3.22 or later. Close plug-in hosts before running the local verification suite; the transport tests use shared-memory sessions. Then run:
./scripts/verify-all.shThis builds and tests both components without installing them. The VST3 build
uses JUCE 8.0.15, fetched automatically unless JUCE_SOURCE_DIR points to a
local checkout. GitHub CI additionally runs the public-history privacy audit,
packaging regression checks and Windows VST3 build/tests. CI does not package
or upload downloads. Results are available in GitHub Actions for each revision.
Passing CI is not a substitute for signing, notarisation or testing in a DAW on
supported hardware.
Use GitHub Issues for setup questions and reproducible bug reports so the answers remain public and searchable. Please do not contact Mike through Instagram, email, or other private channels for individual setup or troubleshooting.
Support is provided on a best-effort basis. Check the Releases page or use the macOS app's manual Check for Updates command. The app never checks, downloads, or installs updates in the background, and the VST3 remains offline.
From 0.3.1, update checks require a matching macOS installer and checksum. Stable releases are the default; Include testing prereleases explicitly includes previews and labels them as such. Users of 0.3.0 or earlier can download 0.3.1 directly from Releases if the older checker misses it.
Created by Mike Konstantinidis while building his own live set, then released as an open-source project for the community.
- Contributions: CONTRIBUTING.md
- Security reports: SECURITY.md
- Changelog: CHANGELOG.md
- Licence: GNU Affero General Public License v3.0
- Project identity: Names, logo and official releases
- Third-party notices: THIRD_PARTY_NOTICES.md
AGPL-3.0 permits redistribution, including selling compliant copies. Third-party forks and services must not be presented as official or endorsed releases. The identity policy does not change the software licence.
Product names are used only to describe compatibility and workflow. MK Crossfader is independent and is not affiliated with or endorsed by the manufacturers mentioned in the documentation. See TRADEMARKS.md.