I recommend Jellyfin as well. Open source, local accounts, and no features locked behind a pass. The Jellyfin TV clients are a little more bare bones but the server software itself is pretty much equal nowadays. I have the lifetime Plex Pass but I have moved away from Plex completely now after the direction they’ve been heading in the last couple of years.
While I can’t offer a solution, it’s not that the rips are quiet. It’s most likely it’s multi-channel audio and your player/headphones is doing a bad job of downmixing it to stereo. It is probably easier to just make sure you are grabbing releases with 2.0 tracks from the beginning.
If you are on Android there is Finamp, which isn’t quite as nice but it is clean and free. If you’re willing to pay a couple bucks there’s also Symfonium which IMO is even better than Plexamp. It has way more customization and I love that it uses Material You.
If you are on Android there is Finamp for Jellyfin. It’s not quite as nice but it is clean and free. There is also Symfonium which is I think $3 but it is even nicer than Plexamp IMO. The great thing about Jellyfin is there are many options.
He uses Arch BTW