Audio setting question..........

Solution
Equalizer setting will usually be tone controls which won't solve you problem. Look for something that sounds like a volume normalizer. If there is such a setting it will tell you exactly which one.
Common problem: look for "equalizer" settings.

Unfortunately some content seems to be able to just blast audio at us no matter what....

Do check the Vizio's TV User Guide/Manual. Likely to be some control but equally likely to be somewhat "hidden". [Cynicism conceded.]