Abstract: Methods, systems, circuits and computer program products provide an output signal to drive an electromechanical transducer that selectively contains a cooling component when a thermal limit of a voice coil of the electromechanical transducer is exceeded and which air-cools the transducer by convection. An indication of a temperature of a voice coil of the electromechanical transducer is determined and compared with a thermal limit of the transducer. If the thermal limit of the transducer is exceeded by the indication of the temperature of the voice coil, the cooling component is introduced to the output signal that drives the transducer. The cooling component is a signal having a frequency within a low-frequency resonance portion of the response of the electromechanical transducer, so that additional air convection is caused at the transducer to remove heat from the voice coil due to the cooling component of the output signal.

Abstract: An audio output system for providing an output signal to a micro-speaker provides energy reduction and thermal protection by removing components of an input signal from which the output signal is generated, so that the audio power output system does not expend power reproducing portions of the audio information that would not be perceived by a listener. The micro-speaker has a resonant frequency such that substantial content of the audio information lies below the resonant frequency. A processing subsystem receives the audio information and generates the output signal by filtering the audio information with a response simulating the micro-speaker and an acoustic path to the listener, and comparing the filtered audio information with a frequency-dependent threshold of hearing. The processing subsystem then removes portions of the audio information that have an amplitude below the frequency-dependent threshold of hearing.