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)

Test

I've not used it that much (just 2 times), but it does what is supposed to. I can increase the max volume so it is now a pleasure to listen youtube when songs are silent even at max volume!

The only problem is this extension "forgets" the sound setting. when you open a youtube video in a new tab, the settings are gone. you have to stop the video, click on the icon, then max the sound setting again. Great extension, annoying problem.