Install jack-mixer by entering the following commands in the terminal:
sudo apt update sudo apt install jack-mixer
Description:
JACK Audio Mixer
jack_mixer is an audio mixer for JACK with a look similar to its hardware counterparts. Many features are available, here is a short list: . - Mix any number of input channels (mono or stereo). - Control balance and faders with MIDI commands. - Handle session management with LASH. - Create as many outputs as necessary. - Quickly monitor inputs (PFL) and outputs.
Homepage: http://home.gna.org/jackmixer/
Version: 10-1build2
Section: universe/sound