PAControl is an alternative to Adam Audio's A Control. It is a command-line tool and a python library.
./pacontrol-cli.py list
./pacontrol-cli.py mute
./pacontrol-cli.py unmute
./pacontrol-cli.py sleep
./pacontrol-cli.py wakeup
./pacontrol-cli.py set \
--input=rca|xlr \
--voicing=pure|unr|ext \
--bass=-2|-1|0|1 \
--desk=-2|-1|0 \
--presence=-1|0|1 \
--treble=-1|0|1