A method for reinforcing the bass frequencies in a digital audio signal intended to be rendered by an equipment comprising a loudspeaker having known characteristics of excursion as a function of the signal applied to its terminals, and an amplifier having known characteristics of maximum voltage of saturation or clipping, characterized in that it comprises the following successive steps of processing: a) converting the digital audio signal, initially with no dimension, into another digital signal representative of an electric voltage ( V E), as a function of a first predetermined gain (G 1) of analogue amplifier; b) applying to the signal obtained at step a) a first filtering of the lowshelf type, adapted to selectively amplify, by a second predetermined gain (G 2), the frequencies lower than a given pivot frequency (F 0); c) calculating a current value of excursion (x) of the loudspeaker for the signal obtained at step b), as a function of said known characteristics of excursion; d) comparing the current value of excursion (x) calculated at step c) with a maximum value of excursion ( x MAX) and calculating a third gain (G 3) of possible attenuation in the case where the current value of excursion exceeds the maximum value of excursion; e) applying to the signal obtained at step a) a second filtering of the lowshelf type, adapted to selectively amplify, by a fourth predetermined gain (G 4), not higher than said second predetermined gain (G 2) and, as the case may be, reduced by the third gain (G 3) of possible attenuation previously calculated at step d), the frequencies lower than the pivot frequency; g) comparing the signal obtained at step e) with said maximum voltage ( v MAX) of saturation or clipping, and calculating a fifth gain (G 5) of possible attenuation in the case where the amplitude of this signal exceeds a threshold function of the maximum voltage of saturation or clipping; h) applying to the signal obtained at step a) a third filtering of the lowshelf type, adapted to selectively amplify, by a sixth predetermined gain (G 6), not higher than said second predetermined gain (G 2) and, as the case may be, reduced by the third (G 3) and fifth (G 5) gains of possible attenuation previously calculated at steps d) and g), the frequencies lower than the pivot frequency; k) reversely converting the signal ( V S) obtained at step h) into a digital audio signal, with no dimension, as a function of said first predetermined gain of analogue amplifier. a) converting the digital audio signal, initially with no dimension, into another digital signal representative of an electric voltage ( V E), as a function of a first predetermined gain (G 1) of analogue amplifier; b) applying to the signal obtained at step a) a first filtering of the lowshelf type, adapted to selectively amplify, by a second predetermined gain (G 2), the frequencies lower than a given pivot frequency (F 0); c) calculating a current value of excursion (x) of the loudspeaker for the signal obtained at step b), as a function of said known characteristics of excursion; d) comparing the current value of excursion (x) calculated at step c) with a maximum value of excursion ( x MAX) and calculating a third gain (G 3) of possible attenuation in the case where the current value of excursion exceeds the maximum value of excursion; e) applying to the signal obtained at step a) a second filtering of the lowshelf type, adapted to selectively amplify, by a fourth predetermined gain (G 4), not higher than said second predetermined gain (G 2) and, as the case may be, reduced by the third gain (G 3) of possible attenuation previously calculated at step d), the frequencies lower than the pivot frequency; g) comparing the signal obtained at step e) with said maximum voltage ( v MAX) of saturation or clipping, and calculating a fifth gain (G 5) of possible attenuation in the case where the amplitude of this signal exceeds a threshold function of the maximum voltage of saturation or clipping; h) applying to the signal obtained at step a) a third filtering of the lowshelf type, adapted to selectively amplify, by a sixth predetermined gain (G 6), not higher than said second predetermined gain (G 2) and, as the case may be, reduced by the third (G 3) and fifth (G 5) gains of possible attenuation previously calculated at steps d) and g), the frequencies lower than the pivot frequency; k) reversely converting the signal ( V S) obtained at step h) into a digital audio signal, with no dimension, as a function of said first predetermined gain of analogue amplifier.