Method of controlling diaphragm excursion of electrodynamic loudspeakers

An apparatus, comprising:

• a processor circuit configured to apply measured voice coil voltage or current information about a speaker to an adaptive digital model of the speaker to estimate a diaphragm excursion of the speaker in response to an input signal, wherein the adaptive digital model includes a plurality of adaptive model parameters configured to be adjusted in response to the detected current or voltage;
• a band splitting system to split the input signal into a high-frequency component signal and a low-frequency component signal according to respective high frequency and low frequency components of the input signal,
• a comparator to compare the estimated diaphragm excursion to a threshold value,
• a signal limiter to alter the low-frequency component signal in response to an output of the comparator, wherein the signal limiter performs dynamic range compression on the low-frequency component signal as the alteration without requiring clipping, and wherein performing dynamic range compression on the low-frequency component signal includes applying a diaphragm excursion dependent gain value to the low-frequency component signal, and
• a signal combiner to merge an output of the signal limiter and the high-frequency component signal from the band splitting system to produce an output signal.

An apparatus, comprising:

• a processor, executing program instructions that cause the processor to operate as:
• a band splitting system to split an input signal into a high-frequency component signal and a low-frequency component signal according to respective high frequency and low frequency components of the input signal,
• an estimator, configured to apply an adaptive digital model of a speaker to estimate excursion of the speaker's diaphragm based on the low-frequency component signal, wherein the adaptive digital model includes a plurality of adaptive model parameters configured to be adjusted in response to the detected current or voltage,
• a signal limiter to alter the low-frequency component signal when the estimated excursion exceeds a predetermined limit, wherein the signal limiter performs dynamic range compression on the low-frequency component signal as the alteration without requiring clipping, and wherein performing dynamic range compression on the low-frequency component signal includes applying a diaphragm excursion dependent gain value to the low-frequency component signal, and
• a signal combiner to merge an output of the signal limiter and the high-frequency component signal from the band splitting system to produce an output signal.