This happened to all of us, at some point. Some parts of the movie are just to loud and it's very uncomfortable, and also, it is a bit annoying when some dialogues are too quiet. We recommend to use VLC's built in compression tool, that will fix this problem and will give you more quality and enjoyable sound.
Go to Tools and then select "Effects and Filters". After that just select the "Compressor" section and enable dynamic range compressor. Now, set the values like in this picture.
It really works, try it. And if you don't have VLC Media Player, safely download it from here.
