Almost every conversation about MPE starts at a keyboard. Seaboard, Osmose, LinnStrument, Exquis — the dominant mental image is a flat or contoured playing surface where you press, wiggle and slide. But per-note expression was never a keyboard idea in the first place. It was an attempt to give electronic instruments the continuous, per-voice control that acoustic instruments have always had — and few instrument families have more of that than winds.
That's what makes the pairing of the WARBL wind controller and Haken Audio's EaganMatrix Micro worth attention, particularly now that Haken's firmware ships presets built specifically for the combination.
Two small boxes, one big engine
The EaganMatrix Micro, introduced in early 2025, is the smallest device to carry Haken's EaganMatrix sound engine — the same physical-modelling-adjacent synthesis architecture found in the Continuum Fingerboard, the ContinuuMini, and (in a licensed form) inside the Expressive E Osmose. It's a self-contained desktop module with no keys of its own, which is exactly the point: it expects an expressive controller to be plugged into it.
EaganMatrix isn't a conventional subtractive or wavetable engine. It's a modulation matrix routing oscillators, biquad filter banks, delay lines and waveshapers, with the expectation that continuous control signals are driving the patch at all times. Play it from a static MIDI keyboard and most patches sound inert. Feed it breath pressure, finger position and continuous bend, and it behaves much more like a resonant physical body being excited.
The WARBL comes from the other direction: an open-source-minded wind controller in the family of electronic whistles and recorders, with fingering-based note selection, breath sensing and a set of continuous sensors. It's small, affordable by wind-controller standards, and — critically — it outputs the kind of dense continuous data that the EaganMatrix was designed to consume.
Presets built for the instrument, not ported to it
The meaningful development is that Edmund Eagan, the sound designer behind the EaganMatrix, has been building preset banks tailored specifically to the WARBL's sensing behaviour rather than adapting keyboard patches. Recent firmware releases have added sets of WARBL-specific default user presets to the Micro, with a walkthrough demonstrating how each maps breath and finger data onto the matrix.
This distinction matters more than it might sound. A patch voiced for a keyboard controller typically assumes note-on velocity carries the attack transient and pressure arrives afterwards as a sustain modifier. A wind controller has no velocity in any meaningful sense — the attack is the breath curve. A preset that expects velocity to shape the onset will feel dead no matter how expressively you play it.
Eagan's WARBL presets reassign that responsibility: breath drives excitation amplitude and spectral content directly, so articulation comes from how you tongue and push air rather than from how fast a key travelled. Finger sensors handle vibrato and timbral position. The result is an instrument that rewards wind technique instead of punishing it.
Firmware, the cross-platform Haken Editor for macOS and Windows, and the user guides are all available from Haken Audio's firmware page.
What wind players can borrow from this
You don't need this exact pair of devices to take something from the approach. A few principles transfer to any non-keyboard MPE setup:
Decide what carries the attack. If your controller doesn't produce meaningful velocity, find the patch parameters tied to velocity and re-route them to pressure or breath CC. This single change fixes more "MPE feels lifeless" complaints than any other adjustment.
Don't map everything at once. Wind controllers produce a lot of simultaneous data. Patches that route breath to four destinations at full depth tend to become uncontrollable. Two well-chosen destinations, one of them subtle, usually plays better.
Watch your note-off behaviour. Breath-driven instruments end notes by running out of air, not by lifting a finger. Release times voiced for keyboards are often far too long, leaving a tail hanging after the player has clearly stopped.
Check the zone configuration. Wind controllers are typically monophonic or limited-polyphony, which means the MPE channel allocation that a 12-voice keyboard patch expects may be wildly oversized. A narrower zone can improve response and reduce channel churn.
A quiet argument for the format
MPE's specification has always been controller-agnostic — nothing in it privileges a keybed. What's held back non-keyboard adoption is content: the preset libraries, defaults and documentation have overwhelmingly assumed keys.
Work like Eagan's chips away at that. It's a small preset bank on a small module, but it's evidence that a serious engine developer considers a wind controller a first-class MPE input rather than an edge case. For guitarists, wind players and percussionists eyeing expressive synthesis, that's the part worth watching.
Sources: Haken Audio, Synthtopia