Issue with sound level.
 

In some of the files I'm watching the background noise is quite loud while the character's dialog is very faint; almost as if the two sound streams are reversed. I'm not sure if the term "sound stream" is correct, but that's what it seems like. I know there's an easy fix for this as I had the same problem on an old laptop. I just can't recall how to do it. Is this an AC3 Filter issue? Any suggestions?

This is usual "problem" with AC3 audio. You can gain voice level by goin' to AC3Filter options.

it's likely your speakers set up

go to the first "Main" tab

and select "2 stereo"

this should fix it :)