sndspeed and snd_mixspeed should be at 44100 or matching the system default.

[LethalManBoob]

It is indeed very noticeable how much it improves audio clarity. Perhaps put an option in the audio menu for it? Also, Is there a notable performance reason as to why snd_filterquality is not set to 5?

[Novum]

No. See https://github.com/Novum/vkQuake/issues/480