jack_mixer is a GTK JACK audio mixer app with a look similar to its
hardware counterpart. It has lot of useful features, apart from being
able to mix multiple JACK audio streams. It is licensed under GPL
version 2 (or later).
https://rdio.space/jackmixer/
https://rdio.space/jackmixer/tarballs/jack_mixer-13.tar.xz
Changes in version 13?
----------------------
* Added NSM support.
* Store preferences to per session config file to override global
preferences.
* Added accelerator shortcuts to menu items.
* New ctrl-click, double-click, scroll, and click-drag-anywhere
fader behaviors.
* Added MIDI 'Pick Up' behavior to avoid discontinuities.
* Can choose output channel colors.
* Changed to logarithmic ramping on volume changes.
* Added a pre/post fader button.
* Pick volume for new channels.
* Allow manual setting of MIDI control change numbers.
* Remove GConf; use plaintext .ini preferences file instead.
* Remove remnants of Swig python bindings.
There is now a GitHub project for your features, or feature
requests, bugs, etc. ->
https://github.com/jack-mixer/jack_mixer
With contributions from Daniel Sheeler and Christopher Arndt, thanks!
Enjoy,
Frederic