The equalizer is available in pulseaudio's master git branch so instead of the git repository below, you may just want to compile from there.

Getting the equalizer

Binary packages are available for the following platforms:.

openSUSE 11.2 and factory:

http://download.opensuse.org/repositories/home://jenewton/

Ubuntu 9.10:

Add the following to your sources.list:

deb http://ppa.launchpad.net/nevion/ppa/ubuntu/ karmic main

Add the following PPA key:

apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 5291C76F

You may have to force these packages to be installed (synaptic->package->force version to the jenewton build).

Unfortunately due to dependencies within pulseaudio, older platforms are not available.

Up to date sources are available here:

git clone git://gitorious.org/pulseaudio-equalizer/pulseaudio-equalizer.git pulseaudio-equalizer
cd pulseaudio-equalizer && git checkout -t origin/master

Getting the GUI (pqaeq):

Note that currently, qpaeq is included in the pulseaudio source tree under src/utils and will be installed alongside the equalizer module to /usr/bin/qpaeq in most setups automatically. Qpaeq is still maintained in the below repositories, however.

Git: git clone git://gitorious.org/qpaeq/qpaeq.git

Direct qpaeq single file download of git: http://gitorious.org/qpaeq/qpaeq/blobs/raw/master/qpaeq.py

Releaseish form here: http://sourceforge.net/projects/qpaeq/

Git versions are usually much more up to date, so give them a try first.

Compiling (for those without packages provided above)

You will then need to install all normal pulseaudio devel dependencies and fftw3 and dbus devel packages (ex dbus-1-devel / libdbus-1-dev). I prefer a local installation but this will still overwrite your old configurations in /etc/pulse, be sure to back up! You can probably use the following commands:

cd pulseaudio-equalizer.git
./autogen.sh
CFLAGS="-O0 -ggdb -mtune=native -fno-strict-aliasing" ./configure --disable-static --disable-rpath --with-system-user=pulse --with-system-group=pulse --with-access-group=pulse-access --libdir=/usr/local/lib64 --sysconfdir=/etc
make
sudo make install
sudo ldconfig

(32bit users will want to use lib instead of lib64 in the above)

Disabling tsched

You probably won't need to do this but if things are messing up, it's something to try (in /etc/pulse/default.pa):

### Automatically load driver modules depending on the hardware available
.ifexists module-udev-detect.so
load-module module-udev-detect tsched=0
.else
### Alternatively use the static hardware detection module (for systems that
### lack udev support)
load-module module-detect tsched=0
.endif

Configuring

Update: The module now automatically makes itself the default sink, so for most users, simply load module-dbus-protocol and module-equalizer-sink. See below for a reference snippet.

You will need to find out the name of your current sink. You can use a gui (paman) for this or perform this command:

pacmd list-sinks|grep 'name:'

The names should be in between the < >. You will probably only have one.

Put something like the following in your default.pa (a few lines are added for context):

.ifexists module-esound-protocol-unix.so
load-module module-esound-protocol-unix
.endif
.ifexists module-dbus-protocol.so
load-module module-dbus-protocol
.endif
load-module module-native-protocol-unix
load-module module-equalizer-sink sink_name=equalized master=alsa_output.pci-0000_00_1b.0.analog-surround-51 set_default=true
set-default-sink equalized

Make sure the dbus module is also loaded as above and that you replace the master=alsa part with master=YOURSINKNAME or it will use the default sink. You can set set_default=false if you do not want the new sink to be the default.

GUI and Equalizing:

You will need python, pyqt4, and python-dbus to launch the gui (qpaeq). Debian packages for those are python, python-dbus, python-qt4 and python-qt4-dbus.

Launch the GUI via:

qpaeq (if you installed from git or opensuse packages)

--or--

python qpaeq.py

If the frequency bands in there aren't good enough for you, add in your own (in order) inside qpaeq.py, its under the variable named DEFAULT_FREQUENCIES. Restart the gui and voilà. The equalizer also automatically subdivides frequency ranges depending on the width of the window and supports presets.

Questions/Comments/Problems

Drop phish3 a line in the irc channel on freenode or join the mailing list.