merge.sh

#!/bin/bash
# Create merged input. Merged all output sources.
# Insert this script in /etc/X11/xinit/xinitrc.d/
if [ "$1" == "-u" ]; then
  # Unload the loopback and null sink modules
  pactl unload-module module-loopback
  pactl unload-module module-null-sink
else
  # Exit if already loaded.
  if pactl list sources short | grep "combined" &>/dev/null ; then
    exit 0
  fi

  # Load a null sink with a specific name and description
  pactl load-module module-null-sink sink=inputs sink_name=combined sink_properties=device.description="Merged Output"

  # Load loopback modules for each source
  for device in $(pactl list sources short | awk '/^[0-9]+/ {print $2}' | grep -v "combined"); do
    echo "$device"
    pactl load-module module-loopback source="$device" sink=combined
  done
fi