I don't know if this matters but I found this directory:

$ pwd
/home/richard/.pipewire-media-session
$ ll
total 8
-rwx------. 1 richard richard 101 Aug 29  2020 default-profile
-rwx------. 1 richard richard 174 Aug 30  2020 default-routes

$ cat default-profile
alsa_card.pci-0000:08:00.1 output:hdmi-stereo-extra2
alsa_card.pci-0000:0a:00.4 output:analog-stereo

$ cat default-routes
alsa_card.pci-0000:08:00.1:output:hdmi-output-2 mute:0 volumes:2,1.000000,1.000000
alsa_card.pci-0000:0a:00.4:output:analog-output-lineout mute:0 volumes:2,0.368683,0.368683


Interestingly it doesn't seem to have been updated since Aug 2020.

Thanks,
Richard