Hi
On previous Ubuntu versions, I would run Ardour over Jackd2. Ubuntu 24 comes with Pipewire installed, what is the method advised for running Ardour?
The recommended back end is ALSA if you are just working on music production with Ardour.
The disadvantage is that while Ardour is running no other applications can send audio to the same interface (although you could have e.g. system sounds sent to the internal speakers of a laptop while Ardour exclusively used a USB interface, Ardour does not have exclusive use of all audio interfaces, only the one selected).
If you need to send audio between applications, or would prefer to let other applications also have access to the audio interface output then you will need to use either jackd or pipewire-jack.
If you want to use jackd, then you will need to remove the pipewire-jack package, and only applications which have jack support will be able to share the interface directly, otherwise you will have to load an alsa-to-jack bridge for other applications.
If you want to use pipewire to share audio, then make sure pipewire-jack is installed, and that you are using the latest available pipewire package (I believe 1.0.5 for Ubuntu 24.04, if you have the 0.3.x version installed you should upgrade). Pipewire continues to provide the ALSA interface to other applications, allowing you to connect applications which do not have native jack support into the audio graph if desired.
Anecdotal experience suggests that Pipewire does not become a reasonable alternative for JACK until around version 1.2.x of Pipewire. If you have an older version of that, there’s a good chance you will experience problems using it as a drop-in replacement for JACK. Later versions work very well (though there are few corner cases still left to be addressed).