Most MPE conversations centre on two things: the controller you play and the synth you play into. The link in the middle — the sequencer that records, edits, and plays back what you performed — has been a persistent weak point. Per-note expression generates a dense stream of data, and hardware sequencers built around one-channel-per-track assumptions simply drop most of it. Squarp Instruments addressed that head-on with Hapax firmware 3.0, a free update that required reworking the sequencer's underlying architecture.
Why It Needed a Major Version Number
Squarp were explicit that the jump from 2.x to 3.0 was not marketing. Supporting MPE properly means a sequencer has to track, store, and replay per-note pitch bend, channel pressure, and CC74 for every voice independently, then rotate those voices across a zone of MIDI channels on playback. That is a fundamentally different data model from "this track sends notes on channel 3."
The result is dedicated MPE zones configurable per track output. You can set a track to the Lower Zone — channel 1 as master, channels 2–15 for member voices — or the Upper Zone, where channel 16 is the master and member channels count downward. Having this configurable per track matters in a hardware studio, where you might be driving an Osmose on one output and a conventional multitimbral module on another from the same project.
128 Expressive Pads
The more surprising part of 3.0 is that Hapax's own pad grid became an MPE controller. Every one of the 128 pads now transmits three dimensions simultaneously: aftertouch as pressure, CC74 as timbre, and pitch bend.
This is a genuinely different proposition from a pad grid that sends velocity and channel aftertouch. It means you can sketch an expressive part directly on the sequencer without patching in a separate controller — press harder on one pad in a held chord and only that voice responds. It will not replace a Continuum or a Seaboard for nuanced playing, since a pad's travel is short and the gesture vocabulary is limited. But for capturing an idea, auditioning how a patch responds to pressure, or performing a filter sweep on a single note inside a sustained chord, it removes a whole step from the workflow.
MIDI Effects and the Expression Problem
Firmware 2.10 had already introduced four MIDI effects — Arpoly (a polyphonic arpeggiator and loop designer), Register (a randomiser), Mono (polyphonic-to-monophonic conversion), and Shapes (non-linear modulation). In an MPE context, these raise an interesting design question that the whole ecosystem is still working through: what should a MIDI effect do with per-note expression data?
An arpeggiator that receives a chord where each note carries its own pressure curve has to decide whether to preserve those curves, average them, or discard them. A monophonic converter has to choose which note's expression stream survives. There is no standard answer, and different implementations across the industry behave differently. This is the kind of edge case that only becomes visible once MPE moves from "the synth supports it" to "the whole signal chain supports it" — which is precisely the transition 3.0 represents.
Where This Fits in 2026
Hapax is not a cheap device, and it sits in a specific niche: producers running multiple hardware instruments who want a capable standalone brain rather than a computer. Within that niche, MPE support has been close to nonexistent. Most hardware sequencers treat expression as an afterthought, if they handle it at all, which has effectively forced expressive-controller players toward a DAW.
The broader trend is that MPE is spreading outward from the endpoints. In 2025 the story was controllers and synths. In 2026 it has been the connective tissue: sequencers, MIDI recorders, file formats like the new MIDI Clip File container, and DAW piano roll editors that can actually display per-note curves. A performance you cannot capture and edit is a performance you cannot really produce with.
Getting Started
Firmware 3.0 and later releases are free for existing Hapax owners and available from the Squarp downloads page. A few practical points:
- Confirm your destination synth's zone configuration matches the track's. A Lower Zone track pointed at an Upper Zone instrument produces silence or stuck notes, and the cause is not obvious.
- Check pitch bend range on both ends. The MPE default is ±48 semitones per note.
- MPE data is dense. If you are chaining devices over a single DIN connection, per-note streams from several tracks can saturate the bus — one of the better arguments for USB or multiple physical outputs.
For anyone building an expressive rig that does not revolve around a laptop, this is one of the more consequential firmware updates of the year.