Loudspeaker excursion prediction system

Patent metadata

Field	Value
Publication number	US-2024406624-A1
Application number	US-202318326032-A
Country	US
Kind code	A1
Filing date	May 31, 2023
Priority date	May 31, 2023
Publication date	Dec 5, 2024
Grant date	—

Abstract

A loudspeaker excursion prediction system, which is suitable for a loudspeaker protection circuit comprises a low-pass filter circuit, a down-sampling circuit, and an impulse response generation unit. The low-pass filter circuit is configured to generate an audio signal X LPF (t) passing through the low-pass filter circuit according to an audio signal X(t) with a first sampling frequency. A down-sampling circuit, coupled to the low-pass filter circuit, is configured to down-sampling the first sampling frequency of the audio signal X LPF (t) output from the low-pass filter circuit to a second sampling frequency, so as to generate a down-sampled audio signal X LPFDN (t). The impulse response generation unit, coupled to the down-sampling circuit, is configured to generate an excursion prediction value according to a loudspeaker excursion transfer function and the down-sampled audio signal X LPFDN (t).

First claim

What is claimed is:

1 . A loudspeaker excursion prediction system, comprising:
a low-pass filter circuit, configured to generate an audio signal X LPF (t) having passed through the low-pass filter circuit according to an audio signal X(t) with a first sampling frequency; a down-sampling circuit, coupled to the low-pass filter circuit, configured to down-sample the first sampling frequency to a second sampling frequency, so as to generate a down-sampled audio signal X LPFDN (t); and an impulse response generation unit, coupled to the down-sampling circuit, configured to generate an excursion prediction value Y(t) according to a loudspeaker excursion transfer function and the down-sampled audio signal X LPFDN (t).

2 . The loudspeaker excursion prediction system according to claim 1 , wherein the first sampling frequency is 48 kHz, and the second sampling frequency is adjustable.

3 . The loudspeaker excursion prediction system according to claim 1 , wherein the second sampling frequency is ⅛ times the first sampling frequency.

4 . The loudspeaker excursion prediction system according to claim 1 , wherein the second sampling frequency is a component of 95% of an excursion response covered within 0.5 times frequency points.

5 . The loudspeaker excursion prediction system according to claim 1 , wherein the impulse response generation unit is an impulse response filter.

6 . The loudspeaker excursion prediction system according to claim 5 , wherein an order of the impulse response filter is designed to be 128-order when the second sampling frequency is 6 kHz.

7 . The loudspeaker excursion prediction system according to claim 1 , wherein a cutoff frequency of the low-pass filter circuit is less than one-half of the second sampling frequency.

8 . The loudspeaker excursion prediction system according to claim 1 , wherein one-half of the second sampling frequency is less than −60 dB.

9 . The loudspeaker excursion prediction system according to claim 1 , further comprising:
an excursion conversion circuit, coupled to the impulse response generation unit, configured to generate the loudspeaker excursion transfer function.

10 . The loudspeaker excursion prediction system according to claim 9 , further comprising:
a protection circuit, coupled to the impulse response generation unit, configured to generate a loudspeaker excursion protection value according to the excursion prediction value Y(t); a gain controller, coupled to the protection circuit, configured to generate an audio signal with a maximum excursion limit according to a delayed audio signal and the loudspeaker excursion protection value; and a delay circuit, coupled to the gain controller, configured to generate the delayed audio signal according to the audio signal X(t).

Assignees

• Elite Semiconductor Microelectronics Technology Inc

Inventors

• Chang Jung-Kuei
• Yu Wun-Long

Classifications

• H04R3/007 Primary

  Protection circuits for transducers · CPC title

• H03G3/20 Primary

  Automatic control ({H03G3/005 takes precedence;} combined with volume compression or expansion H03G7/00) · CPC title

• H04R29/001

  for loudspeakers (H04R29/007 takes precedence) · CPC title

• H04R2430/00

  Signal processing covered by H04R, not provided for in its groups · CPC title