Recently I tested all audio addons, which were updated during the last 12 months. 1000% Sound Booster by username32480 is a simple, modern alternative to the „600% Sound Volume“-family of forks (e.g. lefriend, savva, 1fexd). Two behaviours are very exceptional: It has no problems at all with cross origins; and it breaks DRM-Videos. The max boost is impressive, but hard to enjoy, as the clipping grows as well.