Electric loudspeaker

摘要

The sound radiation of electric loudspeakers is unfavourably affected at low frequencies by the system resonance, resulting in a restriction in the usable frequency range and a poor transient response. In the present invention, this is prevented by using a diaphragm which is partially air-permeable. If said diaphragm moves, a partial pressure equalisation takes place between its front and rear sides. Due to the finite flow resistance of the diaphragm material and the associated frictional losses, the system is additionally dampened. At the same time, the resonance of the loudspeaker system which is installed in the conventional manner in an enclosed housing is split into two resonances, of which one lies above and the other below the original resonance. This is equivalent to a base reflex effect and therefore to a downward extension of the frequency range. The air permeability of the diaphragm can be achieved, for example, by perforation or by using a porous material. There is a favourable range of values for the flow resistance, but this is not particularly critical.