At Christmas 1990 my mother and I were visiting my brother, and the people in the apartment below were blasting their music so loud we actually had to shout to hear each other. We went down and pounded on their door, but got no answer (I doubt they heard us). So we took his 3-foot speakers and laid them face-down supported by a phone book at each end so they were just about 2 inches off the floor, cranked them all the way up, stuffed our fingers in our own ears, and put on a bagpipe record. The noise from below ceased at once. We gave them a full minute, turned it off, and heard not a sound from that direction the rest of the day. There's a reason bagpipes are used on the battlefield.