Comprehensive speaker protection concept for micro-speakers

A comprehensive micro-speaker protection method and algorithm has been developed that prevents micro-loudspeakers as used in mobile applications – mobile phones and tablets - to be overloaded by mechanical or thermal load. This is a non-trivial task since the demand for highest possible output is in contradiction with safe operation. Therefore, the protection algorithms need to allow to reach the physical limits of the device without overloading it. To achieve this target a precise modelling of both thermal and mechanical behaviour of the loudspeaker is needed. The paper introduces firstly the modelling approach for thermal and mechanical load and then discusses an integrated protection method that allows a maximum of output without destroying the loudspeaker.