EP0504562A1 - Sound reproduction system for sound reproduction with spatial sound effect - Google Patents

Abstract

In a sound reproduction system (3) for sound reproduction with spatial sound effect at a specific hearing location (10) in a room limited on all sides, in particular the passenger compartment (2) of a motor car (1), loudspeakers (11, 12, 21, 22) are disposed in this compartment in such a way that they generate a spatial sound. To ensure that this spatial sound effect is positioned at a specific hearing location (10), a specific delay time is provided as a basic setting on sound signal delay devices (13, 14, 23, 24) in the loudspeaker channels (17, 18, 27, 28). A considerable fluctuation range exists for the basic setting, within which a change in the spatial sound effect cannot be heard at the hearing location. In addition, this fluctuation range is exploited in order to set the delay times within the fluctuation range in such a way that a smoothing of the frequency response of the sound level at the hearing location is also achieved. <IMAGE>

Description

The invention relates to a sound reproduction arrangement for a sound reproduction with a spatial sound effect according to the preamble of claim 1.

With such a sound reproduction arrangement, the listener is to be given the reproduction of a sound signal with the impression of a certain spatiality of the sound event in a space limited on all sides. This requires a spatial arrangement of the loudspeakers with respect to the listener, through which sound radiation acts on the listener from several sides. The listener gets the best hearing impression both in the sound image and in the spatial impression when the sound event emitted by the various loudspeakers arrives simultaneously at the location, the listening location, at which the listener is located. Therefore, such sound reproduction arrangements contain devices with which the electrical sound signals transmitted to the loudspeakers are so electrically or acoustically delayed that they arrive as sound signals at the particular listening location at the same time.

Nevertheless, the sound image is more or less distorted at the listening location as a result of interference with disturbing reflections and standing acoustic waves on and between the boundary surfaces of the room. These disturbances occur the more disturbing the smaller the room in which the listening location is located. This applies in particular to the passenger compartment of a car. However, more and more demands are being made on the quality of sound reproduction in motor vehicle sound reproduction arrangements.

The invention has for its object to design an initially specified sound reproduction arrangement so that the quality of the sound reproduction at the listening location is significantly increased with little effort.

This object is achieved according to the invention by the features specified in the characterizing part of claim 1.

It is to the credit of the inventor that he recognized that, on the one hand, to set the delay times for the definition of a specific listening location within a space that is limited on all sides, no high demands are made on the accuracy of these delay times forming the basic setting for the sound signals, and on the other hand that certain deposits of This basic setting, which does not go beyond the permissible tolerance range of the basic setting, in its interaction leads to largely free the frequency-dependent sound level curve at the listening location of the sound field emitted by the loudspeakers of the arrangement from interference-dependent bursts or dips and to achieve a sufficiently smooth curve curve. In most cases, it is only necessary to set existing ones for setting such stores of the delay time from a basic setting additionally adjustable tone signal delay devices in such a way that they can be adjusted more finely or in smaller steps in a narrow time delay range of approximately +/- 1.5 ms. It does not matter whether the audio signal delay devices are part of an equalizer or are arranged separately in the loudspeaker channels. The measures according to the invention also result in the number of bands of the equalizer being able to be reduced substantially without the quality of the equalizer being significantly reduced thereby.

The subclaims characterize advantageous embodiments of the invention.

Fig. 1

eine schematische Darstellung eines PKWs mit einer Tonwiedergabeanordnung für eine Tonwiedergabe mit einem Raumklangeffekt;

Fig. 2

zwei Diagramme (a)) und (b)) über den frequenzabhängigen Schallpegelverlauf am Hörort einer Tonsignalwiedergabe ohne a) und mit b) durch Einstellung einer Verzögerungsablage geglättetem Pegelverlauf;

Fig. 3

Diagramme a) bis d) mit den Verzögerungszeiten der den zugehörigen Lautsprechern zugeleiteten Tonsignale.

The invention is explained in more detail below on the basis of an advantageous exemplary embodiment. The associated drawings show

Fig. 1

a schematic representation of a car with a sound reproduction arrangement for a sound reproduction with a surround effect;

Fig. 2

two diagrams (a)) and (b)) about the frequency-dependent sound level curve at the listening location of a sound signal reproduction without a) and with b) smoothed level curve by setting a delay storage;

Fig. 3

Diagrams a) to d) with the delay times of the sound signals fed to the associated loudspeakers.

The outline 1 in Fig. 1 represents the outline in the diagram of a car, the passenger compartment 2 of which can be sounded through loudspeakers 11, 12, 21 and 22 of a sound reproduction arrangement 3. The loudspeakers are connected to the signal output 4 of associated sound signal delay devices 13, 14, 23 and 24 of equalizers 15, 16, 25 and 26. The two equalizers are fed by the sound signal outputs 19 and 29 of a sound reproduction device 6. In the exemplary embodiment shown, the sound reproduction device 6 contains a tuner (not shown in more detail) which transmits programs received from a transmitter as a sound signal via the sound reproduction device and the equalizers 15 and 25 to the loudspeaker channels 17 and 18 and 27 and 28 of the loudspeakers 11, 12, 21 and 22 . As a further sound source, a cassette recorder 5 is connected to the sound reproduction device 6, the sound events sampled from the tape can be transmitted to the loudspeaker channels instead of the programs received by the tuner.

The loudspeakers 11 and 21 are arranged in the area of the front seats 7 and 8 of the car and the loudspeakers 12 and 22 are arranged in the area of the rear seat 9 in the passenger compartment 2 of the car. The delay time T11, T12, T21 and T22 of the sound signal delay devices 13, 14, 23 and 24 is set for the sound signals generated by the sound reproduction device such that the sound signals S11, S12, S21 and S22 emitted by the associated loudspeakers 11, 12, 21 and 22 Arrive simultaneously at a specific listening location 10, in the exemplary embodiment shown in the region of the head of the driver of the motor vehicle sitting on the left front seat 8 of the motor vehicle. This setting of the delay times T11, T12, T21 and T22 of the sound signal delay devices of the sound reproduction device 3 for positioning the of the Loudspeakers 11, 12, 21 and 22 emitted sound signals S11, S12, S21 and S22 on the specific listening location 10 is the basic setting of the delay times for the specific listening location 10. This basic setting is shown in the diagrams a) to d) of FIG. 3 by the bars Marked 31.1 to 31.4. Diagram a) shows the delay times for loudspeaker channel 27 in bar form, diagram b) the delay times for loudspeaker channel 17, diagram c) the delay times for loudspeaker channel 28 and diagram d) the delay times for loudspeaker channel 18 Accuracy of the delay times of the delay times of the basic setting represented by the bars 31.1 to 31.4 in FIG. 3, as has been established, are not subject to high requirements. In the bar diagrams a) to d) of FIG. 3, the area within which the delay time of the basic setting can be changed is indicated by a bar 35.1 to 35.4 without the spatial impression of the sound event transmitted from the loudspeakers 11 to 22 to the listening location 10 being audible is reduced.

Diagram a) of FIG. 2 shows curve 32 of the frequency response of the sound level of a sound event arriving at listening location 10 for the basic setting of sound signal delay devices 13, 14, 23 and 24 shown in FIG. 3 by bars 31.1 to 31.4. The reflections and standing waves that arise during sound radiation produce a large number of dips 33 and bursts 34 in the frequency response of the level curve, which significantly impair the quality of the sound image of the transmitted sound event at the listening location 10. The sound signal delay devices 13, 14, 23 and 24 contain additional setting devices 20, on which the delay time for the positioning of the listening location by a certain distance A11, A12, A21, A22 from the basic setting within the permissible, by the bars 35.1 to 35.4 of the bar graphs in FIG. 3 shown fluctuation ranges can be changed. By means of these adjustment devices, the respective storage A11 to A22 of the delay time of the individual sound signal delay devices can be set by the delay time of the basic setting in such a way that the individual sound signals S11, S12, S21 and S22 emitted by the loudspeakers 11, 12, 21 and 22 are shifted in phase to the listening location 10 in such a way that a smooth curve 36 of the frequency response of the sound level is produced at the listening location 10, as is shown in diagram b) of FIG. 2 by the smoothed frequency response curve 36 of the sound level at the listening location 10. The delay times of the audio signal delay devices set in this way for smoothing the frequency response curve 36 of the sound level at the listening location 10 are shown schematically in the bar graphs a) to d) of FIG. 3 by the bars 38.1 to 38.4 and the associated shelves A11 to A22 by the bars 37.1 to 37.4 shown.

Claims (3)

Sound reproduction arrangement for a sound reproduction with a spatial effect at least at a certain listening location in a space limited on all sides (2) - With several speakers in a suitable arrangement for generating the spatial sound and with adjustable sound signal delay devices arranged in the loudspeaker channels (17, 18, 27, 28) for setting the listening location, characterized by
that on the loudspeakers (11, 12, 21, 22) associated sound signal delay devices (13, 14, 23, 24) a storage (A11, A12, A21, A22) of the delay time from the basic setting required for the positioning of the particular listening location (10) (31.1 to 31.4) of the delay times (T11, T12, T21, T22) of the electrical sound signals to the loudspeakers is set in such a way that the frequency response (36) of the sound level generated by the loudspeakers at the listening point of interference-dependent level deviations is achieved without losing the positioning of the listening location (33, 34) is largely exempt. A sound display device according to claim 1,
characterized by
that the space on all sides is the passenger compartment (2) of a car (1). Sound reproduction arrangement according to Claim 1 or 2
characterized by
that the audio signal delay devices for setting the storage (A11, A12, A21, A22) of the delay time (38.1 to 38.4) from the basic setting (31.1 to 31.4) the audio signal delay devices (13, 14, 23, 24) of the loudspeaker channels (17, 18, 27, 28) feeding equalizers (15, 16, 25, 26), which are an adjusting device (20) for adjusting the storage of the delay time for smoothing the frequency response (36) of the sound level at the listening location (10) from the basic setting for the Delay times (T11, T12, T21, T22) required for a specific listening location.

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