JACK can live without D-Bus

If D-Bus support is included with your Linux distribution and is working with QjackCtl, you do not need information in this article.

which JACK version?

Most distributions have a number of JACK packages.

package jack2 is preferred for having multiple configuration options, but any JACK version can be used

differences between JACK 1 and JACK2
jack does not use D-Bus, but jack-dbus is a patched jack package using D-Bus
jack2 uses D-Bus, but can run without it

For users with one sound card D-Bus suspends Pulseaudio for Jack to load, and loads pulseaudio links to Jack

For multiple sound cards D-Bus is not needed to suspend Pulseaudio if devices are assigned exclusively to Pulseaudio or JACK
Also, if JACK is started from boot and always on, Pulseaudio can be disabled from connecting to audio hardware in ALSA and D-Bus is not needed

Using JACK without D-Bus:

In QjackCtl > Options > Execute script on Startup add this command if sound card is shared

pacmd suspend true

Pulseaudio sink and source connections can be loaded by script in Execute script after Startup
OR use same commands in terminal when JACK is running:

pactl load-module module-jack-sink channels=2
pactl load-module module-jack-source channels=2

This will create identical Pulseaudio sink and source connections as with D-Bus:

The commands have useful additional options to specify names and connections:

pactl load-module module-jack-sink sink_name=jack_out client_name=voip_in channels=2 connect=no
pactl load-module module-jack-source source_name=jack_in client_name=voip_out channels=2 connect=no
pactl load-module module-jack-sink sink_name=aux_out client_name=aux_in channels=2 connect=no

For 3 basic IDJC connections, without default system connection:

Ready to start IDJC