Giant Speaker at University of Wisconsin -Madison Engineering Expo 2011 

This is a giant speaker constructed for the UW -Madison Engineering Expo in 2011. It was built by a team of PhD students in electrical and mechanical engineering as a fun side project on a limited budget. The cone is made of polycarbonate and is 6 feet in diameter. The cabinet is 8ft x 8ft x 2ft or 128 cubic feet. Everything was custom made by the team, voice coil, magnet assembly, cone, surround, etc. Peak electrical draw is ~6kW. The video displays a chirp from 5 Hz to 500Hz or so. the speaker works best in the 5Hz - 50hz range. The video does no justice for the vibration this thing produces. We found the resonant frequency of the building it was in which caused "annoyance" for people several floors above us in the opposite side of the building. We were partially inspired by Doc Brown's speaker from Back to the Future. A detailed history of the construction process may be found at ludoislabs.com/...