Hi, i use a lot of internal audio on Laptop (don’t judge me lol)
Pulse for lower latency, Alsa for midi.
When I switch to Alsa all my projects don’t have no sound, Alsa has no sound on outputs 1 and 2. 3 and 4 outputs appear with Alsa and I have to go in Audio Connection Manager and change System tab to 3 and 4, which is a pain to do every time, and it means the Arch OS volume slider does not work.
Pulse is almost always higher latency, just because of the design. The only reason to use Pulse would be if you want to be able to hear sounds from other desktop applications while mixing and your system does not use Pipewire yet.
I am not sure which application Arch uses, but probably pavucontrol, which is the PulseAudio control.
If you want a volume control when using the ALSA backend use the Ardour monitor section, that gives you volume control separate from the master bus level.
For some cases, Ardour eliminates possible I/O issues. One such case is automatically saving I/O per device to sessions and restoring connections when switching the backend, e.g. from ALSA to PulseAudio and vice versa.
Which version of Ardour, and which build (official build, from distribution, self build)?
To add to @ccaudle is pointing out, it will likley be saved into a template that you can use for new projects.
Take one of your old projects where you have set things up properly, and save as a template. Then use that for new projects. All setup and ready for both audio drivers.
ALSA outputs 1 & 2 may not be working in Ardour because they are being used by Pulse Audio, and not available to ALSA to be used as outputs.
Can you switch Pulse to use outputs 3 & 4 of the soundcard instead of outputs 1 & 2? Then try outputs 1 & 2 in Ardour ? That may not work, but just a suggestion.
I had a little trouble with configuring my Audio system with USB-audio and occasionally using the built-in laptop audio. I eventually started to temporarily disable Pulse Audio when I am working with Ardour. It is very, very stable and reliable that way for me.
The ALSA backend will request that Pulse release the device. A common reason is that two outputs are for built in speakers and the other two outputs are for headphones.
I believe the original post indicated that only the built-in audio was being used, no mention of an additional audio interface.