LinuxMusicians

There are already threads here dedicated to this topic but I can't remember how clear these were on how to actually get pulse, qjackctl & jack to work together. Cadence uses a slightly different method which you can read about at the URLs.

I'm assuming here that the user wants to make use of pulseaudio for "normal everyday" purposes and to switch to jack, and route pulse through jack, when for example, practicing an instrument when playing youtube videos through jack.

The method is described at these URLs. It didn't work exactly as shown on Linux Mint but perhaps it's a different story on other people's systems.

http://jackaudio.org/faq/pulseaudio_and_jack.html
https://github.com/jackaudio/jackaudio. ... ulseOnJack

Prerequisites:

Linux Mint, perhaps Ubuntu and Debian (mileage may vary), KXStudio, Qjackctl, working Jack Configuration, preferably a low-latency or PREEMPT kernel

Install pulseaudio-module-jack
If you don't want to work at 48kHz, just omit this step. Edit ~/.pulse/daemon.conf and add line
Edit /etc/pulse/default.pa and add lines at the bottom
The original instructions mention using ~/.pulse/default.pa and adding additional modules, but this led to pulseaudio failures on my system.

Last, open qjackctl, click on Setup, Options tab, tick the Execute script after Startup switch, and paste this line into the box.
When you start jack, pulseaudio should now be directed through Jack sink. Check the soundsettings, output device to confirm.

To adjust system volume, use alsamixer
Start / Stop pulseaudio (if necessary) with