Bug Report: Set "Digital Surround 5.1 (HDMI)" as the permanent, default audio profile

Question

Bug Report / Support Request Summary

System: Ubuntu 24.04 Hardware: NVIDIA GTX 1060 6GB -> Integra DRX-R1.1 Receiver (via HDMI)

Goal: Set "Digital Surround 5.1 (HDMI)" as the permanent, default audio profile.

Core of the Problem: Using the pactl list cards command, we discovered that the default audio profiles for the NVIDIA HDMI output have incorrect priorities. The stereo profile is given a much higher priority than the surround sound profile, causing the system to aggressively and automatically revert to stereo.

output:hdmi-stereo: priority 5900 output:hdmi-surround: priority 800

Troubleshooting Steps Attempted:

1. PulseAudio Config: Setting the profile via pavucontrol is not persistent. Adding set-card-profile and set-default-sink to /etc/pulse/default.pa or ~/.config/pulse/default.pa does not work; the system's high-priority stereo rule overrides it.

2. File Override: We determined that on Ubuntu 24.04, the audio profiles are not defined in individual .conf files (e.g., hdmi-output-stereo.conf). System-wide searches using find and grep for the profile name and priority value came up empty in all standard configuration directories (/usr/share/alsa-card-profile, /usr/share/pipewire, /usr/share/wireplumber). This indicates the profiles are being generated dynamically.

3. WirePlumber LUA Script: We attempted to create a user-level WirePlumber rule in ~/.config/wireplumber/main.lua.d/ to raise the priority of the surround profile. Multiple variations of this script all caused the wireplumber.service to crash on restart, resulting in a total loss of audio devices (only a "Dummy Output" remains) until the script is removed.

Conclusion: This appears to be a bug in the default profile generation or rule handling in the wireplumber package for Ubuntu 24.04, specifically concerning NVIDIA HDMI audio devices.