Ableton Forum

Steps to reproduce

I am using an mpe device (linnstrument) in channel per note mode, which rotates through a set of channels for each note pressed. For this example I used channels 2-5. I monitor with MidiView to confirm that as I play notes, they comes through on channels 2-5.

I have an Ableton Live 11.01 instance with a track containing Kontakt in MPE mode. Kontakt is set up with 4 copies of the same instrument in its rack. They are each set to listen on one of midi channels 2,3,4,5.

Expected behavior
As I play notes on the midi controller, sound should come from Kontakt.
The Max MIDI Monitor device should show channel data that matches MidiView and the Linnstrument settings.

Actual behavior
Kontakt plays only some notes. Roughly a 1/4 chance a note plays back.
The Max MIDI Monitor device shows all sounds coming in channel 1.

Thoughts
In other DAWs in MPE mode, notes are sent through to a track's VST on the same midi channel as they came from the device. In Ableton it looks like the channel information is lost and recreated in some way, which means that VST settings that rely on correct channel data will not work as expected.

One other way this comes up is in the open source Surge synth's scene channel split mode. If you set that value to channel 9, then channels 1-8 should control scene A and 9-16 control scene B. But when run under Ableton Live in MPE mode, the channel data is lost and notes control scene A or B randomly.

While many of us are hoping for a change, this is the currently intended behaviour (as of March 2021).

In MPE mode, midi channels are handled in a round-robin manner. Channel 1 is reserved for control information, and any other channel is assigned randomly upon an incoming note message.

To be sure, have you selected MPE in your Midi track’s channel field ?

I think this is annoying too. There are a few types of standards for more selection with MPE. It’s a little surprising to me that Live force translates it. Would be nice if the MPE MIDI effect device offered options for dealing with these different formats.

Thanks for the replies. I would love for someone from Ableton to weigh in on this because it is a big drawback in the new Live 11 MPE functionality. It would be good to know if it's on the roadmap for a fix or if other DAWs are better for MPE in the meantime.

chapelier fou wrote: ↑

Sun Mar 28, 2021 8:02 am

To be sure, have you selected MPE in your Midi track’s channel field ?

Yes, I just double checked. With MPE mode enabled, Surge receives notes on random-ish channels 1-16, ignoring the channel set by my controller. With MPE mode disabled, Surge receives midi on channel 1 only.

That's not a bug but just the way it is as of now.

thanks [jur]