US 12,445,775 B2
Method and system for processing a digital audio signal to improve the rendering of low frequencies
Paul Gagneur, Poissy (FR); and Benjamin Eller, Paris (FR)
Assigned to FAURECIA CLARION ELECTRONICS EUROPE, Paris (FR)
Filed by Faurecia Clarion Electronics Europe, Paris (FR)
Filed on Aug. 23, 2023, as Appl. No. 18/454,494.
Claims priority of application No. 22 08459 (FR), filed on Aug. 23, 2022.
Prior Publication US 2024/0073602 A1, Feb. 29, 2024
Int. Cl. H04R 3/00 (2006.01); H04R 1/02 (2006.01); H04R 3/08 (2006.01); H04R 9/06 (2006.01); H04R 29/00 (2006.01)
CPC H04R 3/08 (2013.01) [H04R 1/025 (2013.01); H04R 9/06 (2013.01); H04R 29/001 (2013.01); H04R 2499/13 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method for processing a digital audio signal to improve the rendering of the low frequencies, implemented in an audio system including a transducer comprising a magnetic element suitable for generating vibrations based on the frequency of the audio signal and having an associated maximum excursion value, the transducer further having a specific cutoff frequency, the method comprising:
A) performing a high-pass filtering of the digital audio signal having an associated filtering frequency, the filtering frequency being greater than or equal to 10 Hz and less than two thirds of the specific cutoff frequency of the transducer, the high-pass filtering producing a filtered digital audio signal,
B) applying, to said filtered digital audio signal, a first low shelf filter, said first low shelf filter performing an amplification of the frequencies, comprised in a frequency range that is less than a predetermined limit frequency, said first low shelf filter having a predetermined first amplification gain,
C) estimating an excursion value of the transducer for the signal obtained after applying the first low shelf filter,
D) when the estimated excursion value of the transducer exceeds the maximum excursion value, calculating a second amplification gain that is less than the first gain,
E) applying, to said filtered digital audio signal, a second low shelf filter performing an amplification of the frequencies comprised in said frequency range that is less than the predetermined limit frequency, and of gain equal to the second calculated gain, the application of the second low shelf filter resulting in a filtered and amplified digital audio signal, for which the transducer has an excursion value that is less than the maximum excursion value.