Is youtube and sound working for you at normal speed with sound in Whonix 13 / 14?
Related:
Testers wanted! Upgrade Qubes-Whonix 13 -> Qubes-Whonix 14
⚓ T780 sound / video broken in Qubes-Whonix 14
This might be just a localized issue with my computer and not a general Qubes-Whonix issue.
Working fine for me in both 13 and 14.