In Steam, right click on Rocksmith and choose "Properties". Set the following launch options:
PROTON_LOG=1 PROTON_DUMP_DEBUG_COMMANDS=1 %command%
then start the game from Steam again. You will now have a script at /tmp/proton_$USER/run
that represents the command Steam runs when starting the game. If we run this script, Rocksmith can start via Steam and have sound. (PIPEWIRE_LATENCY="256/48000" /tmp/proton_$USER/run
)
Let's copy the script to somewhere else and give it a better name. This is an example that I will use in the rest of the guide. You can change the path or the name of the script, if you want to.
cp /tmp/proton_$USER/run $STEAMLIBRARY/steamapps/common/rocksmith-launcher.sh
Please continue with the guide.