Non-electric sound amplifier - is in form of half dome and is constructed from rigid panels and support bars

摘要

A non-electric sound amplifier is constructed from a set of rigid panels (1, 2, 3, 4) and support bars (5, 6) of which the weight of any one part is not greater than 100 kg. The individual parts are provided with means of fastening one to another. When assembled the parts form a structure which forms a half dome under which a group of singers can stand. The height and dia. of the half dome can be increased by fitting additional flat rigid panels around the base and along the vertical centre line. USE - Non-electric amplification of sound from group of singers.