I normally use renoise over jack. If I forget to start jack, renoise will start one for me. The jack process I start using qjackctl is called jackd, the one renoise starts is called jackdbus.
What’s the difference and why not use jackd?
Can this be configured somewhere?
Why does renoise leave the jackdbus that it started running?
It’s not Renoise which starts Jack in case it’s not running. Jack does so by its own, as soon as the first client uses jack an no jack server is running.
If I remember well, you can configure this “how to start jack” behavior in~/.jackrc or /etc/jackrc. Depending on your system, installed Jack version and stuff, this may be a bit more complicated.