fluidsynth/doc/polymono/poly_mono_1.txt

# How to change the whole set of actual basic channels ?
# -------------------------------------------------------------
# Assuming you want to set 2 groups of channels:
# Group 1: first channel 5 in poly mode, only one channel
# Group 2: first channel 10 in mono mode , only one channel

# Group 1 should have following settings:
# basic channel 5, mode poly, omni off, (mode 2).

# Group 2 should have the following settings:
# basic channel 10, mode mono, omni off, (mode 3), composed of one channel.

# First use the command resetbasicchannels to  reset all basic channels
resetbasicchannels 

# Then use command setbasicchannels using numbered mode 2 and 3:
setbasicchannels  5 2 0   10 3 1
# or using named mode:
# setbasicchannels  5 poly_omnioff 0   10 mono_omnioff 1

# Use basicchannels command to verify your settings
basicchannels


# end