2.3.3. Integrating PulseAudio with JACK
The default configuration of PulseAudio yields control of the audio equipment to JACK when the JACK server starts. PulseAudio will not be able to receive input or send output of any audio signals on the audio interface used by JACK. This is fine for occasional users of JACK but many users will want to use JACK and PulseAudio simultaneously or switch between the two frequently. The following instructions will configure PulseAudio so that its input and output is routed through JACK.
Use PackageKit or KPackageKit to install the pulseaudio-module-jack package.
Approve the installation and ensure that it is carried out properly.
You'll need to edit the PulseAudio configuration file to use the JACK module.
Be careful! You will be editing an important system file as the root user!
Run the following command in a terminal: sudo -c 'gedit /etc/pulse/default.pa'
Add the following lines, underneath the line that says [code]#load-module module-alsa-sink[/code]:
load-module module-jack-sink
load-module module-jack-source
Restart PulseAudio by running the following command in a terminal: killall pulseaudio PulseAudio restarts automatically.
Confirm that this has worked by opening QjackCtl. The display should confirm that JACK is "Active".
In the "Connect" window, on the "Audio" tab, there should be PulseAudio devices on each side and they should be connected to "system" devices on the opposite sides.
Open QjackCtl's "Setup" window, then click on the "Options" tab. Uncheck "Execute script after Shutdown: killall jackd". If you did not make this change then QjackCtl would stop the JACK server from running every time the program quits. Since PulseAudio is still expecting to use JACK after that you shouldn't do this any more.
When PulseAudio starts JACK, it uses the command found in the ~/.jackdrc file. QjackCtl automatically updates this file when you change settings, but you may have to restart both PulseAudio and JACK in order to get the new changes to take effect. If they refuse to take effect you can edit that file yourself.
Be careful about using a very high sample rate with PulseAudio, since it will tend to use a lot of CPU power.