Abstract: A method of controlling sound reproduction may include applying an audio signal to a voice coil of the electrodynamic loudspeaker to produce sound, detecting one of an impedance and admittance of the loudspeaker across a predetermined audio frequency range based on a detected voice coil current and voice coil voltage and determining a fundamental resonance frequency of the loudspeaker based on the detected impedance or admittance. The fundamental resonance frequency of the loudspeaker may be compared with a nominal fundamental resonance frequency of the loudspeaker representing a nominal acoustic operating condition of the loudspeaker. A change of operating condition of the loudspeaker may be detected based on a frequency deviation between the determined fundamental resonance frequency and a nominal fundamental resonance frequency of the loudspeaker. The level of the audio signal may be attenuated in response to the frequency deviation meets a predetermined frequency error criterion.

Abstract: A method of detecting enclosure leakage of an electrodynamic loudspeaker mounted in an enclosure or box may include applying an audio signal to a voice coil of the electrodynamic loudspeaker through an output amplifier and detecting a voice coil current flowing into the voice coil. A voltage across the voice coil may be detected and an impedance or admittance of the loudspeaker across a predetermined audio frequency range may be detected based on the detected voice coil current and voice coil voltage. A fundamental resonance frequency of the loudspeaker may be determined based on the detected impedance or admittance and compared with a nominal fundamental resonance frequency of the loudspeaker representing a sealed state of the enclosure. Acoustic leakage of the enclosure may be detected based on a deviation between the determined the fundamental resonance frequency and the nominal fundamental resonance frequency of the electrodynamic loudspeaker.

Abstract: A method of detecting enclosure leakage of an electrodynamic loudspeaker mounted in an enclosure or box may include applying an audio signal to a voice coil of the electrodynamic loudspeaker through an output amplifier and detecting a voice coil current flowing into the voice coil. A voltage across the voice coil may be detected and an impedance or admittance of the loudspeaker across a predetermined audio frequency range may be detected based on the detected voice coil current and voice coil voltage. A fundamental resonance frequency of the loudspeaker may be determined based on the detected impedance or admittance and compared with a nominal fundamental resonance frequency of the loudspeaker representing a sealed state of the enclosure. Acoustic leakage of the enclosure may be detected based on a deviation between the determined the fundamental resonance frequency and the nominal fundamental resonance frequency of the electrodynamic loudspeaker.

Abstract: A method of controlling sound reproduction may include applying an audio signal to a voice coil of the electrodynamic loudspeaker to produce sound, detecting one of an impedance and admittance of the loudspeaker across a predetermined audio frequency range based on a detected voice coil current and voice coil voltage and determining a fundamental resonance frequency of the loudspeaker based on the detected impedance or admittance. The fundamental resonance frequency of the loudspeaker may be compared with a nominal fundamental resonance frequency of the loudspeaker representing a nominal acoustic operating condition of the loudspeaker. A change of operating condition of the loudspeaker may be detected based on a frequency deviation between the determined fundamental resonance frequency and a nominal fundamental resonance frequency of the loudspeaker. The level of the audio signal may be attenuated in response to the frequency deviation meets a predetermined frequency error criterion.