Hermetically closed loudspeaker housing - has prismatic shape with triangular base with two-layer walls, one of plastics the other of granulate-filled soft polyurethane or rubber

摘要

Multi-ply loudspeaker casing is prismatic with triangular base; has a 2-ply wall fo which the outer ply is ribbed and consists of a thermoplastics or some other moulding cpd., reinforced with fibres, whilst the other ply, also provided with ribs, doubles as damper nd is composed of relatively light-wt., flexible, material e.g. a polyurethane resin, rubber or soft thermoplastics, in which hard, heavy granulate, e.g. grit or metal (grape) shot is embedded. The casings is packed with glass- or mineral fibres and is hermetically sealed.