US 9,813,812 B2
Method of controlling diaphragm excursion of electrodynamic loudspeakers
Kim Spetzler Berthelsen, Køge (DK); Miguel Alejandro Chavez Salas, Cambridge, MA (US); and Kasper Strange, København Ø (DK)
Assigned to Analog Devices Global, Hamilton (BM)
Filed by Analog Devices Global, Hamilton (BM)
Filed on Dec. 12, 2014, as Appl. No. 14/569,182.
Prior Publication US 2016/0173983 A1, Jun. 16, 2016
Int. Cl. H03G 11/00 (2006.01); H04R 3/00 (2006.01); H03G 9/00 (2006.01); H03G 9/02 (2006.01); H04R 29/00 (2006.01)
CPC H04R 3/007 (2013.01) [H03G 9/005 (2013.01); H03G 9/025 (2013.01); H04R 29/001 (2013.01); H04R 2430/03 (2013.01)] 27 Claims
OG exemplary drawing
 
1. A method of controlling diaphragm excursion in a speaker, the method comprising:
when an audio input signal is being applied to a coil of a speaker, detecting at least one of a current flowing through a coil of the speaker and a voltage across the coil of the speaker;
splitting the audio input signal into a first component and a second component, the first component in a predetermined frequency band;
estimating a diaphragm excursion of the speaker using an adaptive digital model of the speaker, wherein the adaptive digital model includes a plurality of adaptive model parameters configured to be adjusted in response to the detected current or voltage, the estimating including applying information to the adaptive digital model about the detected current or voltage and about the first component of the audio input signal; and
when a magnitude of the estimated diaphragm excursion exceeds a specified threshold value:
altering the first component of the audio input signal to provide an altered first component of the audio input signal, wherein the altering includes performing dynamic range compression on the first component without requiring clipping, and wherein the performing dynamic range compression on the first component includes applying a diaphragm excursion dependent gain value to the first component; and
combining the altered first component of the audio input signal with a second component of the audio input signal at another frequency band to provide a combined signal.