sometimes the sound of videos isn't enough for me. so i reach the sound indicator , over sound preferences and change it to a level higher than 100%. the question is how can i do it from the keyboard? now i can control the volume from the keyboard but it's maximum is 100%. is there a way to do that?

EDIT 1: how to use amixer to do it? (as Lyrositor suggested)

EDIT2: the closest answer , as Jo-erland, suggested is to set a hotkey to bring up the gnome-volume-control, and then to use left and right arrows to change volume also beyond the 100% mark.

any other suggestions, to make this 1 step only? is it possible to set a hotkey to do a sequence of commands ?