How do I start pulseaudio-equalizer?

Question

I just installed pulseaudio-equalizer on my Ubuntu 17.10 following the answer here with:

sudo apt-get install pulseaudio-equalizer

When I want to start the application I get:

$ pulseaudio
E: [pulseaudio] pid.c: Daemon already running.
E: [pulseaudio] main.c: pa_pid_file_create() failed.

How can I start pulseaudio-equalizer?

Answer 1

To start the pulseaudio equalizer run:

qpaeq

If this gives you the error

There was an error connecting to pulseaudio,
please make sure you have the pulseaudio dbus module loaded, exiting...

then load these two modules using pactl:

pactl load-module module-equalizer-sink
pactl load-module module-dbus-protocol

and, to make these changes permanent, edit ~/.config/pulse/default.pa (create it if necessary) and add these lines:

load-module module-equalizer-sink
load-module module-dbus-protocol

If you are a wayland user, start the equalizer this way instead:

QT_QPA_PLATFORM=wayland qpaeq

Answer 2

Edit: I've created a small setup script that creates all the three files and puts them in the right places. Just download the script and execute it in a terminal: sh pulseaudio-equalizer-setup.sh

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If you only need/want the sound equalizer running while the equalizer GUI is open, I created a minimal working solution with these files:

~/.config/pulse/default.pa — make the dbus-protocol module load by default

.include /etc/pulse/default.pa

# Needed by module-equalizer-sink.
load-module module-dbus-protocol

~/.local/bin/equalizer — must be made executable

#!/bin/sh
pactl load-module module-equalizer-sink
pactl set-default-sink "$(pactl list sinks short | awk '/equalizer/ { print $2 }')"
qpaeq
pactl unload-module module-equalizer-sink

~/.local/share/applications/equalizer.desktop — create icon in applications menu

[Desktop Entry]
Name=PulseAudio Equalizer
GenericName=Sound Equalizer

Type=Application
Terminal=false
Exec=equalizer
TryExec=qpaeq
StartupWMClass=qpaeq

Icon=audio-headphones
Categories=Qt;AudioVideo;

Note 1: Make sure that ~/.local/bin is in your PATH. Otherwise, either move the executable file to a directory that is in PATH (e.g. /usr/local/bin) or substitute the command in the Exec= entry by an absolute path to the script.

Note 2: To run the application immediately after installing the files to the correct places, run this command before:

$ pactl load-module module-dbus-protocol

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Tip: If you resize the equalizer's window, widening it, more controls appear for narrower audio frequency bands, allowing fine-grain tuning.

Answer 3

This answer is meant to be in support of those already here. A great way to solve a problem like the one above is to type

apropos pulseaudio | grep \(1\)

and you should end up with a list of every command on your machine with the word pulseaudio anywhere in it's manual's description. Typing man -k has the same effect as apropos, but the latter is easier to remember, in my opinion.