US 12,425,786 B2
Speaker distortion compensation device and speaker unit
Yuji Saito, Fukushima (JP); Katsuhiko Egami, Fukushima (JP); and Hiroyuki Taguchi, Fukushima (JP)
Assigned to Alps Alpine Co., LTD, Tokyo (JP)
Filed by Alps Alpine Co., LTD, Tokyo (JP)
Filed on Jan. 31, 2023, as Appl. No. 18/103,558.
Claims priority of application No. 2022-030014 (JP), filed on Feb. 28, 2022.
Prior Publication US 2023/0276185 A1, Aug. 31, 2023
Int. Cl. H04R 29/00 (2006.01); H03G 9/02 (2006.01); H04R 3/00 (2006.01)
CPC H04R 29/001 (2013.01) [H03G 9/025 (2013.01); H04R 3/002 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A speaker distortion compensation device configured to compensate for distortion in an output from a speaker with respect to an input signal, the speaker distortion compensation device comprising:
a sensor configured to detect vibration of a vibration system included in the speaker;
a non-linearity compensation filter configured to accept the input signal;
a tunable filter configured to accept an output from the non-linearity compensation filter and to output an output signal that drives the speaker;
an adaptive algorithm execution unit configured to execute a predetermined adaptive algorithm to perform an adaptive operation in which a transfer function of the tunable filter is updated so that vibration detected by the sensor does not undergo distortion with respect to the input signal; and
a controller configured to perform, as an initial setting operation for the speaker distortion compensation device, an operation in which the controller calculates a non-linear parameter of the speaker as an active non-linear parameter and sets, in the non-linearity compensation filter, a transfer function that compensates for distortion in the output from the speaker with respect to the input signal, the distortion being due to the calculated active non-linear parameter;
wherein in the initial setting operation, the controller is configured to:
drive the speaker by using a predetermined test signal and measure a response from the speaker as a measured response value, the response being measured from vibration of the vibration system, the vibration being detected by the sensor with respect to the test signal,
calculate error between the measured response value and a theoretical response value, which is a theoretical value of the response from the speaker when the non-linear parameter of the speaker, the non-linear parameter being theoretically determined from design specifications of the speaker, is taken as a non-linear parameter theoretical value and the non-linear parameter theoretical value is the non-linear parameter of the speaker, and
calculate, when the calculated error is smaller than a threshold level, the non-linear parameter theoretical value as the active non-linear parameter.