Enable equalizer in pulseaudio

default.pa.add

# Install pulseaudio-equalizer
# SYSTEM WIDE: add the equalizer section and optionally the default sink to /etc/pulse/default.pa
# USER: just create ~/.config/pulse/default.pa with the contents below

.include /etc/pulse/default.pa

## Equalizer section
# For the equalizer to work you need to set the sound output through the equalizer with pavucontrol
# another way is to set the equalizer as the default sink but this is no recommended
# since some applications can perform with laggy sound
# Enable equalizer module
.ifexists module-dbus-protocol.so
load-module module-dbus-protocol
.endif
.ifexists module-equalizer-sink.so
load-module module-equalizer-sink
.endif

# OPTIONAL
## This line only applies to my system, and sets my default sink (sound source)
# to check your sinks and choose the default sink perform
# pacmd list-sinks | grep "name:"
# and change the line below according to the desired sink.
set-default-sink alsa_output.pci-0000_00_1b.0.analog-stereo