Osmose’s Augmented Keyboard Action sends MPE+ messages to the internal EaganMatrix sound engine. MPE+ is what Haken Audio calls their optimized extension to the MPE standard (MIDI Polyphonic Expression). You will find more information on its specifities here: https://www.hakenaudio.com/mpe
If you wish to trigger the EaganMatrix with MIDI messages coming from another source than the internal keybed of Osmose, we recommend to use the USB MIDI Haken Port (Port 2) as input. If you wish to use the DIN MIDI input instead, then make sure that a "dsp in" option is chosen for the "din mode" of the MIDI I/O tab of Osmose's global settings.
There are some things to pay attention to when trying to trigger the EaganMatrix with MPE messages:
Individual notes must be sent on MIDI channels #2 to #14. The Master Channel according to the MPE standard is #1. MIDI channels #15 & #16 are used for communication with the Haken Editor exclusively, so make sure to not send note data on these channels.
In order to produce a sound in the first place, it is always required to send Channel Pressure messages (sometimes called "mono aftertouch") alongside your Note On messages. This is because with MPE+, a constant flow of Channel Pressure messages is used to describe a sound's envelope, specifically its attack trajectory. Indeed, MIDI Velocity ("MPE Strike") is ignored entirely by the EaganMatrix’s when it comes to the MPE implementation.
It’s also possible to trigger notes in the EaganMatrix by sending regular, "legacy" mono-channel MIDI to the device. Stick to these guidelines to make it work:
MIDI messages must be sent on the Master Channel (#1).
MIDI Velocity will be interpreted as a first Pressure (Z) data value for the respective note to start with.*
Polyphonic Key Pressure (Polyphonic Aftertouch) messages can be used to modulate Pressure (Z) on a per-note basis over time.
Channel Pressure (often called Monophonic Aftertouch) will be ignored completely.
Pitch Bend messages will affect all notes in the same manner.
*Due to the simplistic projection that happens when replacing the stream of pressure data for the attack trajectory with a single MIDI Velocity value, the sound generated may differ noticeably from what happens when playing it from Osmose’s keybed. This will vary from preset to preset as it depends on how gestures are implemented for the specific sound.