I in my case I think it had a lot to do with the small venue, a college gymnasium. I sat near the back and could physically feel the music hit me, bounce off the back wall and hit me again.That surprised me when I saw them. In fact, I've only seen one band that was louder than them ................Led Zeppelin.One of the loudest concerts I ever attended. My ears rang for a week. I think there was some blood!