Sound Fixer is one of the best and most reliable extensions I've ever found for sound problems on Facebook, and YouTube. I've been using it for about 10 months, and it has not let me down. 👍👍

Rewelacja do cichych nagrań! Brawo!

Nice app

works well on music.youtube.com

Brilliant extension exactly what I've been looking for and works very well ; )

Nice. I was looking for one that had gain, but the pan and mono settings are usefull in some cases

A must have app for using YouTube.

I've tried half a dozen volume boost extensions to make quiet youtube videos louder, and this is the only one that worked immediately on installation. (firefox 60.9.0esr on linux)