Multi skinned sound insulating door - has hollow space inside frame containing absorbent material, and holes for resonator

摘要

The door, or other similar wall-fitted element which can be detached from the surface of a wall, is made up from several layers, the outer ones of which are interconnected by a frame running round the periphery. Within this frame (7) and between the outside shells (1) of the wall there is a hollow space (10) filled with sound absorbent materials (12), either wholly or partially, running round inside. A resonator is provided in the form of outwards opening through-holes (17) in the frame. These may be rows of round holes, or slits running parallel to the plane of the wall. There may be several rows, with the holes or slits in one offset relative to those in the next. The frame which forms the plate of the resonator, may be made of foamed sound absorbent plastic or cellular rubber.