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.