Jack + Pulseaudio

primeiro passo, instalar o pulseaudio-module-jack

sudo apt install pulseaudio-module-jack

segundo passo. ir em /etc/pulse/default.pa
e trocar

load-module module-jackdbus-detect channels=2

por:

load-module module-jackdbus-detect channels=2 connect=0 

 terceiro: criar os seguintes scripts no qjackctl:

execute script on Startup: pulseaudio -k
execute script after Startup: pulseaudio --start; pactl load-module module-jack-sink channels=2; pactl load-module module-jack-source channels=2; pacmd set-default-sink jack_out
execute script on Shutdown: pulseaudio -k
execute scritp after Shutdown: killall jackd; pulseaudio --start

Referências

1. http://flavioschiavoni.blogspot.com.br/2010/05/jack-e-pulse.html
2. http://linuxmao.org/tiki-index.php?page=pulseaudio%20vers%20jack&structure=Accueil+Tutos&redirectpage=pulseaudio%20vers%20jack
3. https://rodrigocarvalho.blog.br/configurando-pulseaudio-com-jack-no-ubuntu-10-04/
4. http://jackaudio.org/faq/pulseaudio_and_jack.html