Novel Method for Reducing Acoustic Phase Distortions in a Motor Vehicle

Abstract

The method of the invention uses the difference between the acoustic distortions at the left-hand and right-hand front locations mainly in the frequency bands for which said distortions have different signs.

Claims

1. A method for adjusting the stereophonic phase of an automobile sound reproduction installation of the type consisting of inverting the electrical phase between the two channels in certain frequency bands and characterized by the fact that a change of the relative phase between the left and right channels is operated for the frequencies where the phase distortions between the channels for the two listening positions [.sub.L.sub.R].sub.L and [.sub.R.sub.L].sub.R are of different signs to make them of the same sign.

2. A method for adjusting the stereophonic phase of an automobile sound reproduction installation according to claim 1 and characterized in that the electrical phase is reversed between the two channels at frequencies where the modulus of the sum of the distortions phase at the left and right listening positions is greater than 180.

3. A method according to claim 1 and characterized by the fact that one proceeds to symmetrize the stereophonic phase distortion at the two listening positions by applying between the two channels a shift of the stereophonic phase equal to half of the difference in acoustic phase distortions between the two channels at the two listening positions.

4. Device for reproducing stereophonic modulations in the automobile for the implementation of the method according to claim 1 comprising an electronic control unit and power and several speakers.

5. A motor vehicle equipped with a sound modulation reproduction device according to claim 4.

Description

[0058] This improvement is due to the treatments applied to the frequencies where the distortions do not have the same sign. The symmetrization being a special case.

[0059] In some cases, we can opt for a symmetrical setting and in others cases we will prefer slightly to favor a listener.

[0060] But in both cases it will be more comfortable to perform the first symmetrization which automatically addresses the case of frequencies for which the distortions do not have the same sign and gives a clear view of the quality of the configuration.

[0061] From this symmetrization, it is possible to make phase modifications for example to slightly favor one channel with respect to the other. The necessary and sufficient condition not to increase the total distortion is to preserve for the two distortions the sign obtained after symmetrization.

[0062] This process may be the subject of an electro-acoustic device for equipping motor vehicles.