| 摘要 |
The panel (13) for at acoustic system is formed from fibre material and is covered on both sides by surface layers (14). The panel can be oscillated in a direction perpendicular to its major plane, for generating or damping sound travelling in the surrounding air. - The central part of the panel can be provided with e.g. surface stabilising layers of an air permeability greater than that of the remainder of the panel. The central part thus dampens the panel oscillation proportional to the oscillation velocity change in this central part. |
