EP3280161B1 - Speaker system - Google Patents

Description

Embodiments of the present invention relate to a loudspeaker system for a vehicle, in particular with a loudspeaker array, generally to loudspeaker arrays with a plurality of electroacoustic sound transducers in different arrangement configurations and to a loudspeaker array with sound guidance.

Future infotainment systems in vehicles and the associated loudspeaker systems in vehicles must be able to cope with demanding tasks in complex traffic scenarios. This requires an absolutely reliable function, whereby dangers in any driving situation for the driver, e.g. due to malfunctions, must be ruled out. Here, communication requirements and fast provision of information as well as undisturbed audio playback play an important role. Interfering signals are not just vehicle noises, but also parallel consumption of different audio content, such as simultaneous phone calls and consumption of media content from the perspective of several passengers. Such challenges require system properties that enable individual sound reinforcement to limited listening areas, so-called sound or listening zones.

In addition to the electro-acoustic components, the realization of these systems typically requires efficient algorithms for noise suppression and powerful data communication for controlling the adaptive system.

Based on this problem, there are already a number of concepts that are already being used or at least partially tested on the market. One example is personalized sound reinforcement (by means of sound zones) by using loudspeakers in the immediate vicinity of the listener's ears in the respective sound zone, eg by integrating loudspeakers into the corresponding headrests of the respective car seat for each listening zone. Such a clustered speaker system is disclosed in the patent U.S. 8,126,159 disclosed. An advantage of this approach is the high acoustic separation from the neighboring sound zones, due to the large difference in listening distance. Here is based on the theoretical model of level reduction with approx. 6 dB per doubling of distance (with ideal spherical wave propagation). A disadvantage of this approach is the high sensitivity to interference, for example as a result of head movements. On the one hand, this leads to strong level fluctuations and significant impairments of spatial perception, e.g. loss of stereo images.

A second prior art approach relates to the personalized sound zones that can be created using ultrasonic technology. Audible sound is modulated onto ultrasonic carriers and radiated in a highly focused manner onto the auditory zones. The basic prerequisite for this modulation principle is the emission of very high ultrasonic levels, e.g. greater than 130 dB. The advantage of this approach is that due to the favorable relationship between the wavelength and the size of the active "radiating surface", defined by the size of the loudspeaker or the size of the loudspeaker array, the ultrasound is radiated in a more focused manner than frequencies in the audio frequency range. This enables a higher acoustic separation of the sound zones with the same size of loudspeaker technology used. The disadvantage of this approach is not only that ultrasound can be harmful to health from a certain power level (cf. use of ultrasound in the medical field to destroy kidney stones), but also that the use of ultrasound leads to strong reflections in the vehicle interior, which adversely affect acoustic channel separation. Furthermore, the use of ultrasound requires a high level of power, which is synonymous with low energy efficiency. In addition, there is a strongly non-linear transmission behavior due to the demodulation principle, which results in a low sound quality that is usually only sufficient for speech reproduction.

Another prior art approach is based on so-called beamforming. To this end, several loudspeakers are used, which are distributed in the vehicle and/or grouped into a loudspeaker array, for example. Targeted control of each loudspeaker results in a directed sound emission, eg for individual sound zones. In connection with this, for example, refer to the patent specification U.S. 8,073,156 referenced, which discloses the use of linear speaker arrays in a vehicle. This makes it possible to focus a sound pattern on one or more positions in the vehicle. The patent document U.S. 2012 / 0 121 113 discloses the use of a further loudspeaker array in a vehicle, including the corresponding controller. The advantage over the first approach is the more stable sound zone, even when the head moves. Furthermore, there is no immediate proximity to the seating position to a loudspeaker installation position necessary. In comparison to the second-mentioned approach, there is no risk potential due to the high sound pressure. In addition, better sound quality can be achieved compared to this ultrasonic approach. A disadvantage, however, is the sound focusing that can be achieved, which often results in insufficient channel separation, in particular due to the achievable array dimensions, the achievable transducer distances (distance from adjacent electroacoustic transducers) and the number of transducers per array. In addition, the channel separation of previous beamforming approaches is reduced by the room acoustic influences in the vehicle, reflections or room modes.

Furthermore, the patent discloses U.S. 7,343,020 an automotive audio system with directional, planar sound transducers to generate stereo or surround sounds for each passenger individually. The patent specification US2003/0021433 discloses a speaker configuration together with a signal processor for stereo channel generation for each passenger individually through the use of a center speaker. The patent specification EP 2 143 300 B1 discloses a vehicle speaker system with directional sound transducers, aligned to the respective seating positions (= listening positions). All three of the last-mentioned approaches from the US/EP patent specifications have in common that insufficient channel separation or crosstalk can occur due to the loudspeaker technology to be derived. Therefore, there is a need for an improved approach.

the EP 1 427 253 A2 shows a loudspeaker system for a vehicle with a loudspeaker array. the JP H05 199595 A D3 shows the installation of sound converters in a vehicle with a plurality of sound guides and sound outlet openings for each sound converter.

The object of the present invention is to create a concept for a loudspeaker system, in particular for a vehicle loudspeaker system, which avoids the disadvantages described above and thus enables high-quality surround sound generation with good channel separation. In particular, the aim of the invention is to enable space-saving installation.

The object is solved by the subject matter of the independent patent claims. Further embodiments are defined in the dependent claims.

One embodiment includes a speaker system for a vehicle having a speaker array. The loudspeaker array includes a plurality of electroacoustic sound converters that can be controlled individually, so that a user-specific audio signal for different users at different listening positions in a vehicle interior of the vehicle can be reproduced via the plurality of electroacoustic sound converters. The speaker array or in the case of deployed Sound guides a sound outlet of the speaker array is in particular between at least two of the listening positions in the vehicle interior, for example between the driver and the passenger seat, are arranged.

The exemplary embodiments of this aspect are therefore based on the recognition that a speaker system for a vehicle, in particular with regard to channel separation, e.g. when playing different audio content at the different listening positions, can be improved by placing a speaker array centrally in the sense of centered on all or the relevant listening positions. The loudspeaker array used can set up a separate sound cone for each listening position (or each relevant listening position) or, for example, in the case of stereo, several separate sound cones per zone. By arranging the loudspeaker array in the middle, e.g Direction are also oriented in opposite directions, which is optimal in terms of channel separation, especially for user-specific audio playback.

As already indicated above, a preferred positioning of the loudspeaker array according to the exemplary embodiments would be in the roof liner of the vehicle, in the center console, in the dashboard or in the parcel shelf, it being particularly important according to further exemplary embodiments that there is a distance between the array and the listening positions or at least the relevant listening positions (subset of all listening positions) is essentially the same, ie with a deviating +/- 30%.

According to further exemplary embodiments, at least one additional loudspeaker can be provided for each listening position, for example the loudspeaker usually present in the door or the mirror triangle and/or a differently positioned additional loudspeaker. The additional loudspeaker can also be designed as a structure-borne noise converter. The additional loudspeaker is preferably arranged closer to the user than the loudspeaker array. Such a dense arrangement makes it possible for the sound radiated by the additional loudspeaker to be almost negligible in relation to the other listening positions, since one can work here with significantly lower sound levels and large level differences due to the large difference in the listening distance. This additional speaker makes it possible to produce stereo, but also mono with local level boosting or frequency expansion (e.g. bass) for each listening position.

Stereo can also be generated using the majority of the electroacoustic sound transducers and the loudspeaker array based on the technique of acoustic beamforming. In this case, for example, at least two beams (sound cones) or a stereo beam are generated per listening position. In this context, it must also be mentioned that it would be conceivable for the sound sources to be generated to be positioned virtually in space with the aid of transfer functions that emulate psychoacoustic effects. According to additional exemplary embodiments, it would be advantageous when positioning the sources by means of beamforming for the beams to be tracked taking into account the seating position or the head position of the listener, so that a consistently good reproduction impression is produced regardless of the seating position.

According to a further exemplary embodiment, the loudspeaker system includes a signal processor which, for example for beamforming, individually controls the electroacoustic sound converter and/or the additional loudspeaker or loudspeakers.

The invention creates a loudspeaker array with a plurality of electroacoustic sound transducers which are coupled on their sound emission surface with sound guides for sound output or for sound guidance, each sound guide comprising a sound exit opening. The majority of the sound outlet openings are arranged in such a way that an average distance between the sound outlet openings is smaller than a (possible) average distance between the electroacoustic sound transducers arranged next to one another.

This is based on the finding that, in the case of loudspeaker arrays, a compact distribution of the individual sound sources is to be preferred, in particular with regard to the selective focussing of the sound in the sound emission. In order to achieve a compact distribution even in arrays with large dimensions, e.g. as a result of large sound transducers, according to the invention (for this third aspect) funnel-shaped sound guides, which are each coupled to an electroacoustic sound transducer, are used. The sound exit openings of the sound guides are smaller than the sound inlet openings of the sound guides, so that the sound exit openings can be arranged as a compact field. Thus, the directivity for an array coupled to a plurality of sound guides can be improved.

Fig. 1a

ein exemplarisches Schaubild einer Anordnung eines Lautsprecher-Arrays in einem Fahrzeug gemäß einem ersten Ausführungsbeispiel (Mono) ;

Fig. 1b

ein schematisches Schaubild einer Anordnung in einem Fahrzeug gemäß einem weiteren Ausführungsbeispiels (teilweise Stereo) ;

Fig. 1c,d

schematische Schaubilder von der Anordnung eines Lautsprecher-Arrays in Kombination mit Zusatzschallwandlern in einem Fahrzeug gemäß weiteren Ausführungsbeispielen (teilweise Stereo);

Fig. 2a

ein schematisches Schaubild eines Lautsprecher-Arrays mit Schallwandlern unterschiedlichen Typs für das Lautsprechersystem gemäß den Ausführungsbeispielen aus Figs.1a-1d;

Fig. 2b

ein schematisches Schaubild eines Linienförmigen Lautsprecher-Arrays mit Schallwandlern unterschiedlichen Typs gemäß einem Ausführungsbeispiel ;

Fig. 2c

ein schematisches Schaubild eines Lautsprecher-Arrays mit flächig angeordneten Schallwandlern unterschiedlichen Typs gemäß einem weiteren Ausführungsbeispiel;

Fig. 2d

ein Schaubild eines Lautsprecher-Arrays mit Schallwandlern unterschiedlichen Typs gemäß einem zusätzlichen Ausführungsbeispiel; und

Fig. 3

ein schematisches Schaubild eines Lautsprecher-Arrays mit einer Vielzahl an Schallführungen gemäß einem Ausführungsbeispiel der Erfindung.

Exemplary embodiments of the present invention are explained below with reference to the accompanying drawings. Show it:

Fig. 1a

an exemplary diagram of an arrangement of a speaker array in a vehicle according to a first embodiment (mono);

Fig. 1b

a schematic diagram of an arrangement in a vehicle according to a further exemplary embodiment (partially stereo);

Fig. 1c, d

schematic diagrams of the arrangement of a loudspeaker array in combination with additional sound transducers in a vehicle according to further exemplary embodiments (partially stereo);

Figure 2a

1 shows a schematic diagram of a loudspeaker array with sound transducers of different types for the loudspeaker system according to the exemplary embodiments Figs.1a-1d ;

Figure 2b

a schematic diagram of a linear loudspeaker array with sound transducers of different types according to an embodiment;

Figure 2c

a schematic diagram of a loudspeaker array with two-dimensionally arranged sound transducers of different types according to a further exemplary embodiment;

Fig. 2d

a diagram of a loudspeaker array with sound transducers of different types according to an additional embodiment; and

3

a schematic diagram of a loudspeaker array with a plurality of sound guides according to an embodiment of the invention.

Before exemplary embodiments of the present invention are explained in detail below with reference to the figures, it should be noted that the same elements or structures are provided with the same reference symbols, so that the description of the figures is interchangeable or applicable to one another.

Fig. 1a Figure 1 shows a schematically illustrated vehicle interior 10 in plan view with four listening positions 12a, 12b, 12c and 12d, each defined by a seat on which the potential listener can sit. The loudspeaker system 1 for the vehicle interior 10 comprises a loudspeaker array 20, comprising the plurality of electroacoustic sound transducers 20a-20h.

As illustrated here, the array 20 is arranged relatively centrally in relation to the vehicle interior 10, with the result that the array 20 is arranged at least between two listening positions (subset of all listening positions 12a-12d), here even between the four listening positions 12a-12d is. Possible installation spaces for the loudspeaker array are, for example, the roof liner, the center console, but also alternatively the dashboard or rear shelf. Generally speaking, this means that the loudspeaker array 20 can be installed above or below or even at the level of the listening zones 12a-12d or the ear level of the listener. For the sake of completeness, it should be noted that the term centrally refers to all listening zones 12a-12d or at least to a subset of the listening zones 12a-12d, eg listening zones 12a and 12b. The functionality of the loudspeaker system realized in this way for the vehicle is discussed below.

In the example shown, the loudspeaker array forms a sound lobe 22a-22d for each listening position 12a-12d, which is preferably aligned with the listening zones 12a-12d or at least assigned to them. The formation of these sound cones 22a-22d takes place in that the sound transducers 20a-20h of the loudspeaker array 20 are controlled differently, for example taking into account so-called beamforming algorithms, which can also include the radiation characteristics of the individual transducers 20a-20h and the room acoustic influences. In connection with this signal processing, reference is made to the fundamentals of the theory of wave field synthesis, which largely provides the basis for the beamforming carried out here. This means that the loudspeaker array 20 is designed to construct a separate sound cone 22a-22d for each listening position 12a-12d, with each sound cone 22a-22d being directed in opposite directions (from the center to the listening positions 12a- 12d) is oriented. In addition (due to the central arrangement), the loudspeaker array 20 is approximately equidistant from each listening position 12a-12d, so that each sound lobe 22a-22d has similar characteristics (e.g. extent and level). . These two properties contribute significantly to the achieved channel separation between the channels 22a-22d. An advantage of the sound lobes 22a-22d generated by means of beamforming is that the channel separation is so good that user-specific audio signals can be generated for the listening zones 12a-12c. As a result, not only a different audio signal in terms of loudness but even different audio content can be reproduced in the different listening zones 12a-12d. In addition, it would also be conceivable that in one of the sound zones 12a-12d silence can be generated in a targeted manner by sound cancellation.

Referring to the embodiment of FIG Fig. 1a it should be noted that the arrangement shown even satisfies a second optional specification, namely that the distance between the loudspeaker array 20 and the individual listening positions 12a-12d is essentially the same, ie with a tolerance of +/- 30% ( central arrangement). The central position of the array 20 also reduces disruptive influences of the room acoustics with regard to the sound zones, for example as a result of sound reflections on side windows.

According to exemplary embodiments, instead of the entire loudspeaker array 20, a sound outlet of a sound guide (cf. 3 ) coupled to the speaker array may be positioned centrally or generally between at least two of the listening zones 12a-12d. The sound guide typically includes a sound conductor coupled to the respective sound transducer 20a- 20h for each sound transducer 20a- 20h, with a plurality the sound outlets of the sound conductors form the sound outlet of the sound guide. As a result, the actual sound transducer array 20 can then be accommodated at a suitable location in the car (for example in the trunk), for example for reasons of space, and the sound guide can guide the sound to the corresponding central sound outlet point.

With loudspeaker arrays arranged in this way, it is also possible to generate stereo or even 3D surround sound for each listening position 12a-12d, as referred to in FIG Fig. 1b is shown.

Fig. 1b shows the top view of the vehicle interior 10 with the four listening positions 12a-12d and the loudspeaker array 20 of the loudspeaker system 1. The generation of stereo is explained using the position 12a, but can also be transferred to the other listening positions 12a-12d.

As in Fig. 1b 1, a double sound lobe comprising sound lobes 22aL and 22aR is generated for listening position 12a. The sound beams 22al and 22ar are aimed at the left ear (22aL) and at the right ear (22aR) of the listener at the listening position 12a. The generation of sound channels per listening position 12a-12d is not limited to the number 2 for stereo. Rather, several sound cones per listening position 12a-12d can be generated in order to simulate spatial sound, for example. In accordance with further exemplary embodiments, it would also be conceivable that when generating the sound beams 22aL, 22aR, 22b, 22c and 22d (beams) in the signal processing, transfer functions which emulate psychoacoustic effects are taken into account in order to better position the virtual sound sources in the interior 10 be able. Examples of such transfer functions are HRTF functions and/or Blauert bands.

According to further exemplary embodiments, it would also be conceivable for sound reflections (e.g. via glass surfaces) or sound absorption to be taken into account when aligning the sound cones 22aL, 22aR, 22b, 22c and 22d. So it is taken into account in advance to what extent direct sound reproduction and/or indirect sound reproduction, i.e. including wall reflections or optional sound guides, is used.

According to further exemplary embodiments, it would be conceivable that the sound cones 22aL, 22aR, 22b, 22c and 22d, depending on the seating position, which is the listening position 12a, 12b, 12c and 12d are aligned. An informational coupling of the loudspeaker system to the (electrical) seat adjustment would be conceivable here, for example.

Another embodiment of the speaker system is in 1c and 1d disclosed, in which the central loudspeaker array 20 is combined with at least one additional loudspeaker or additional loudspeaker array (or generally with an additional loudspeaker system comprising at least one additional loudspeaker). Possible positions for the additional loudspeaker(s) are the A, B, C pillars, the headrest or the roof liner.

1c shows the vehicle interior 10 (top view) with the four listening positions 12a-12d, the centrally arranged loudspeaker array 20 of the loudspeaker system 1', with the first listening position 12a being assigned an additional loudspeaker 30a (here e.g. in the roof liner, alternatively B-pillar or headrest). is. From the perspective of the listener, this additional loudspeaker 30a is located at the listening position 12a on a side facing away from the loudspeaker array 20 (here on the left) and is preferably but not necessarily arranged closer to the ear than the central loudspeaker array 20 ensures that a further optional condition, namely that the additional loudspeaker 30a is arranged closer to a listening position 12a compared to the other listening positions 12b-12d, is met.

As shown here, the additional loudspeaker 30a generates a sound lobe 32aL, which is assigned a listening position 12a to one (left) ear of the listener, while the other (right) ear is irradiated by the sound lobe 22aR (generated by the loudspeaker array 20). It is thus possible in the exemplary embodiment shown to generate stereo at the listening position 12a. The use of the additional loudspeaker 30a is not limited to stereo, so the additional loudspeaker 30a can generally serve to support the sound reinforcement at the listening position 12a (mono with level boost). It is advantageous here that the additional loudspeaker 30a is positioned close to the listening position, so that the laws of the sound level drop with distance are exploited, which means that the sound level of the additional loudspeaker 30a in the associated listening zone 12a is louder than in the foreign listening zones 12b-12d. This primarily contributes to the increased acoustic separation of the sound zones 12a-12d. In general, the advantages of one of the additional loudspeakers 30a can be seen in the fact that the sound quality and the spatial impression for the associated sound zone can be improved by utilizing psychoacoustic effects be improved. In general, it should be noted that arranging sound transducers 20 or 30a as close as possible to the listening position (here 12a), cf. e.g. sound transducers 20 and 30a in relation to listening position 12a, increases the proportion of direct sound, so that reflections are largely covered or are negligible.

Fig. 1d shows the vehicle interior 10 with a loudspeaker system 1" in a side view. The listening position 12b and the listening position 12d are shown here, it also being possible to see that the loudspeaker array 20 is arranged centrally above the listening positions 12d and 12b (i.e. in the roof liner). For the (font) listening position 12d, on which the sound cone 22d is aligned, an additional loudspeaker 30d (here in the parcel shelf for generating the sound cone 32d) is provided which, in terms of properties and purpose, differs from the additional loudspeaker 30a 1c is equivalent to.

According to further exemplary embodiments, as also here in Fig. 1d shown, it is possible that a structure-borne sound exciter is provided as an additional loudspeaker for each listening position, here 12d and 12b. In the exemplary embodiment shown, the seat for the listening position 12b includes the structure-borne sound exciter 35b, while the seat for the listening position 12d includes the structure-borne sound exciter 35d. Each of these structure-borne sound exciters 35b and 35d is mechanically fixed to the seat (seat frame or headrest) for the listening position 12b or 12d (e.g. via the footwell) or generally associated with the location of the listener and designed to output structure-borne sound 36b or 36d , so that it reaches the respective listener. These structure-borne sound converters 35b and 35d are particularly suitable as support in the low-frequency range, in which sound reproduction with small arrays (because of the limited array size) would not be able to be focused sufficiently. Optional sound decoupling means can ensure that the structure-borne sound 36d or 36b cannot be heard in other auditory zones, eg 12a and 12c, which in turn contributes to increasing the acoustic separation between the sound zones 12a-12d.

Figure 2a 1 shows a loudspeaker array 50 having a plurality of type A transducers 52a-52d and a plurality of type B transducers 54a-54d. The type A transducers differ in particular in their size, and thus typically, but not necessarily, in their transmissible frequency range from the electroacoustic sound transducers 54a-54d of type B (B for the high-frequency range, eg >1000 Hz or 500Hz; A for the low-frequency range, eg <2000 Hz or <500Hz). Furthermore, the directional characteristics of the type A sound transducers 52a-52d can also be different from the type B sound transducers 54a-54d. The transducers 52a-52d and 54a-54b are in Arranged in the form of a line-shaped transducer array 50 and have a total of fewer transducers than in the case of the structure with two parallel arrays of type A and B of the same length. this in Figure 2a The array arrangements 50 shown in line form can advantageously be used as arrays for the loudspeaker systems 1, 1' or 1". Figures 1a-1d be used.

Even if that regarding Figure 2a explained array was shown in the form of A, B, A, B, A, B, A, B, the basic idea of the alternating arrangement can also be transferred to transducer arrays with more than two different transducer types, so that, for example, a transducer - Arrangement of A, B, C, A, B, C would be conceivable. Another conceivable alternative would be the sound transducer arrangement A, A, B, B, A, A, B, B.

Referring to Figure 2b a loudspeaker array 60 will now be explained in which further advantages come to light. With regard to the loudspeaker array 60, it is also noted that this could also be used for loudspeaker systems outside of the motor vehicle sector, or that the array 60 alone offers advantages. Figure 2b shows a loudspeaker array 60 with the sound transducers 52a-52f (type A) and the sound transducers 54a-54f (type B). Here the sound transducers 52a-52f and 54a-54f are arranged along the line of the array 60 in such a way that an average distance d _{B between} the sound transducers 54a-54f is smaller than an average distance d _{A between} the sound transducers 52a-52f, compare d _B < d _A. Furthermore, it can also be determined that the average distance of the transducer of type B d _{B is} also smaller than the average average distance d _{AB of} all transducers used (cf. Figures 2a and 2b ). Such a formation of the mean distance d _B in relation to the mean distance d _A can be realized by the appropriate sequence of the different sound transducers 52a-52f or 54a-54f.

As in Figure 2b shown, a possible form of realization would be the combination of the sound transducers in the form of A, A, B, A, B, B, B, A, B, A, A Figure 2b In the array 60 shown, four sound transducers of type B, cf. 54b-54e, are arranged in the inner area 60i, which are each framed by a sound transducer of type A (cf. 52c and 52d) on each side, this arrangement in turn being surrounded by a sound transducer of type B (cf. 54a and 54f) is framed. This entire sound transducer arrangement is then in turn framed by two sound transducers of type A (cf. 52a, 52b, 52e and 52f) on each side. Such a distribution can also be described in other words as logarithmic or at least approximately logarithmic.

In this sound transducer arrangement of array 60, it can be ensured that in the interior (compare area marked with reference number 60i) there is a high density of type B sound transducers, which work in the high-frequency range and tend to be characterized by good adjustment of the radiation characteristics. This applies in particular in comparison to the outer area or outer areas 60a. With such an arrangement, the two system-immanent conditions can be taken into account, namely that for the focused radiation the loudspeaker array 60 should be larger than the wavelength, which is particularly problematic for low-frequency reproduction due to the size of the sound transducers 54a-54h, and that at the same time for error-free reproduction, the distance between adjacent loudspeakers should be smaller than the wavelength, which is particularly problematic for high-frequency reproduction due to the size of the sound transducers 52a-52h.

This in Figure 2b The principle of the quasi-logarithmic arrangement described can also be transferred to flat arrays of sound transducers, as in Figure 2c will be shown. Figure 2c Figure 12 shows an array 70 having a central B-type transducer 54e surrounded by a total of eight B-type transducers 54a-54i therearound (ie, one on each side). In this respect, a 3×3 field of type B electroacoustic sound converters 54a-54d is generated by the electroacoustic sound converters 54a-54d. This 3×3 array of acoustic transducers 54a-54i is located at the center of gravity of the array surface 70 in relation to the entire transducer arrangement 70. This center of gravity is identified by reference number 70i. The 3x3 field of sound transducers 54a-54i is in turn surrounded all around by the sound transducers 52a-52h, of type A.

In this exemplary embodiment, the average distance between the sound transducers 54a-54i, which is referred to as density due to the two-dimensionality, is smaller than the average distance between the sound transducers 52a-52h in the outer region 70a. This means that the density in the inner area 70i is higher compared to the density of the outer area 70a (defined by the number of sound transducers 52a-52h and 54a-54i per area). With this surface arrangement, too, it is possible to achieve a small transducer distance from highly focused emissions in the transducers 54a-54i for the high frequency ranges and a larger transducer distance (for focused radiation) for the lower frequency ranges (cf. transducers 52a-52h) due to the design .

Even if the planar transducer arrangement was only explained in the form of a checkerboard pattern of the transducer array 70, it should be noted that other planar arrangements, e.g. concentric arrangements, with a concentration of transducers of a specific type (B) in a specific area, e.g. in the center (70i) would be conceivable, in which the "sound transducer density" varies over the area. The arrangement of the type A/B sound transducers does not necessarily have to be symmetrical either. An asymmetrical arrangement, ie a slightly offset high-frequency array (cf. 54a-54i) in the center 70i of the low-frequency array (cf. 52a-52h), would also be possible. In this way, a reduction in artifacts in the radiation function as a result of points of discontinuity can advantageously be achieved. The cause of such effects is, for example, edge reflections in tweeters that are placed centrally on the front of the housing.

The speaker arrays 60 and 70 are the arrays for the embodiment Fig. 1a-d can be used and are compared to the loudspeaker array Figure 2a Advantages in relation to the directional effect, in particular in the case of beamforming for setting the directional characteristic both in the low-frequency and in the high-frequency range, and can also contribute to the avoidance of spatial aliasing effects.

The concentration of type B transducers in the center 60i and 70i and type A transducers in the outer region 60a and 70a achieved by the transducer arrays 60 and 70 can also be achieved by a two-level transducer arrangement, as described with reference to FIG Fig. 2d is described.

the Fig. 2d shows a loudspeaker array 80 with a multiplicity of sound transducers 52a-52h (type A), which are arranged linearly (directly) next to one another in a first plane. Furthermore, the sound transducer array 80 comprises a multiplicity of sound transducers 54a-54h (type B), which are also arranged in a line next to one another (adjoining one another). These two sound transducer types 52a-52h and 54a-54h are arranged in two different planes, ie one behind the other or offset or one above the other. Both arrangements of the line arrays have in common that the line on which the sound transducers 52a-52h and 54a-54h are arranged is the same in the sense of being parallel. It is thus possible, despite the direct juxtaposition of the transducers of the same type 52a-52h or 54a-54h, that the average distance d _{B of} the transducers of type B (54a-54h) is smaller than the average distance d _{A of} the transducers of type A (52a-52h).

It should be noted that it is irrelevant for this exemplary embodiment whether the sound transducers of type A are arranged in the first or second plane and, conversely, whether the sound transducers of type B are arranged in the first or second plane.

Optionally, however, it is important that the type B sound transducers, which are therefore preferably arranged with a smaller mean distance d _B , are positioned in the center of the type A sound transducer arrangement, so that this exemplary embodiment of the loudspeaker array also results in a concentration of Sound transducer for the high-frequency range can be done in the center.

In further exemplary embodiments, it would also be possible for further sound transducers, e.g. type C sound transducers, to be arranged in a third plane.

Referring to the speaker arrangements from the Figures 2a-2d it should be noted that complex directional characteristics can be assigned to the individual transducers 52a-52h or 54a-54h, for example by sound guides or by the sound transducer itself.

Another embodiment relates to a combination of multiple line arrays, such as arrays 50 and 60, to form a planar speaker array. The line arrays 50 or 60 can have a different number of sound transducers here, so that the line arrays can also have different lengths, for example. Furthermore, it would also be conceivable that the sound transducer distances vary per line array, e.g. due to the fact that different types of sound transducers are used. Corresponding to further exemplary embodiments, each line array can in itself comprise different sound transducer types, the combination of line arrays with one type per line array being preferable. An exemplary embodiment is characterized in that two line arrays with acoustic transducer type A enclose three line arrays with acoustic transducer type B. A flat loudspeaker array is then formed in which a specific type of sound transducer is concentrated in the center.

Referring to 3 an extension for the above loudspeaker arrays is described below, whereby the extension is not limited to such arrays or the automotive sector.

3 shows a loudspeaker array 90, designed here as a combination of eight sound transducers 52a-52h of the same type. Each of these sound converters 52a-52h or, to be precise, the membrane 56 of the sound converters 52a-52h is coupled to a sound guide 92a-92h on its emission side. These sound guides 92a-92h are funnel-shaped and optionally curved elements, so that the sound outlet openings (see reference number 94) of the sound guide 92a-92h are smaller (in all or at least one dimension) than the sound inlet openings (see reference number 56) on the side of the electroacoustic sound transducers 52a-52h. The funnel of the sound guide 92a-92h is designed in such a way that the sound inlet 56 is offset compared to the sound outlet openings 94, with a different offset ratio being used depending on the combination with a sound transducer 52a-52h, so that the total area of the sound outlet openings can be reduced overall .

As a result, the sound outlet openings 94 of the sound guides 92a-92h can be arranged close together with a mean distance d _S . As a result, despite a loudspeaker array 90 extending over a large area, a very small average distance d _S between the sound outlet openings 94 (especially in comparison to the average distance d _A ) is achieved, which leads to an improved adjustable directional characteristic (due to the reduction in the sound emission area through the compact Distance d _{S of} the sound outlet openings 94 or due to the reduced virtual sound transducer distance d _S ) and better positioning of the array (eg in the vehicle) contributes.

The combination of the sound guide 92a-92h with one of the loudspeaker arrays 50, 60, 70 or 80 is possible, so that the sound guide can also be used for the exemplary embodiments of the loudspeaker system 1, 1′ or 1″ from the figs 1a-1d it is a possibility. It is then also possible (as already indicated above) to design the sound guide 92 in such a way that the actual sound transducer array 90 (or also 50, 60, 70, 80), e.g. for reasons of space, can be installed at a suitable point in the car (e.g is housed in the trunk) and the sound guide 92 leads the sound to the corresponding sound outlet point, for example in the roof, which enables space-saving installation.

Referring to 1 it should be noted that the loudspeakers or loudspeaker arrays of the loudspeaker system can also be arranged with a predetermined orientation, for example to the listening positions 12a-12d, so that a directed radiation per sound transducer is possible, which reduces the influence on the room acoustics in the sound zones by the position of the loudspeakers.

According to further exemplary embodiments, a signal control device can also be created which controls the array 20 or the extended arrays 50, 60, 70, 80, 90 according to the principles described above (cf. mono reproduction of the listening zone 12a-12d or stereo reproduction of the listening zone 12a-12d). controls and thus allows the formation of the corresponding number of highly focused sound radiation beams 22a-22d, 22aL, 22aR.

Referring to 1 it should also be noted that the user-specific signals can also be understood to mean the display of other audio information, such as in infotainment signals or telecommunications audio in a specific listening zone, eg the driver's listening zone 12a.

According to further embodiments, the speaker system may include a crossover network or a processor configured to add the input signal, if it comprises only listening content (ie content for a person at a respective listening/sitting position), the middle and higher frequencies to the array , For example, in such a way that beam forms can be operated, provide and output the low frequencies to the structure-borne noise transducer of the respective seating position. In the event that the audio content to be reproduced comprises several parallel contents, e.g. intended for different listening/sitting positions, the crossover network or the audio processor is designed to provide the middle and higher frequencies of all audio content to be reproduced to the array, specifically in the way that the audio content is reproduced separately for the different listening zones at the different listening positions using beamforming, while the lower frequencies are split off and forwarded separately to the different structure-borne sound transducers in the different seats or listening positions. All in all, this offers the advantage that medium and higher frequencies for the various listening positions are reproduced in a directed manner by means of the array, while the low frequencies are only represented locally via the structure-borne sound transducer. The background to this approach is that the low frequencies in particular cannot be directed so well via arrays, so that separating them using beamforming often causes difficulties. By using the structure-borne sound converters, which are explicitly assigned to the individual sitting or listening positions, there is no superimposition of the sound signals from these sound converters.

Further exemplary embodiments create a loudspeaker array with a plurality of first electro-acoustic sound transducers arranged on a first line and a plurality of second electro-acoustic sound transducers arranged on the first line or a line parallel to the first line. In this case, an average distance (d _B ) between the first electro-acoustic sound transducers is smaller than an average distance (d _A ) between the second electro-acoustic sound transducers.

Further exemplary embodiments create a loudspeaker array with a plurality of first electro-acoustic sound transducers, which are arranged in a first flat area, and a plurality of second electro-acoustic sound transducers, which are arranged in the first flat area. In this case, an average density of the first electro-acoustic sound transducer is smaller than an average density of the second electro-acoustic sound transducer.

Further exemplary embodiments create a loudspeaker array with a plurality of electroacoustic sound transducers which are coupled to first sound guides for sound output in a first area, each sound guide comprising a sound exit opening. Here, the majority of sound exit openings are arranged in such a way that an average distance (d _S ) between the sound outlet openings is smaller than a possible average distance (d _A ) between the electroacoustic sound transducers arranged next to one another.

Referring to speaker array 20 from FIG Figures 1a-1d it should be noted that the geometric alignments of the sound transducers 20a-20h in the loudspeaker array 20 shown in the schematic sketches are fictitious and do not necessarily correspond to reality. The alignment of the individual sound transducers 20a-20h can deviate accordingly or even vary from position to position (tilted sharply to the first side, tilted to the first side, downwards, tilted to the second side, tilted sharply to the second side).

Additional embodiments and aspects of the invention are described that can be used individually or in combination with the features and functionality described herein.

According to a first aspect, a loudspeaker system 1, 1', 1'' for a vehicle can have the following features: a loudspeaker array 20, 50, 60, 70, 80, 90 with a plurality on electroacoustic sound transducers 20a-20h, 52a-52h, 54a-54i which can be controlled individually, so that a user-specific audio signal for different users at different listening positions 12a-12d can be reproduced in a vehicle interior 10 of the vehicle, the loudspeaker array 20, 50, 60, 70, 80, 90 or a sound outlet 94 of the loudspeaker array 20, 50, 60, 70, 80, 90 between at least two of the listening positions 12a -12d is arranged in the vehicle interior 10, the loudspeaker system 1, 1', 1" comprising at least one additional loudspeaker system for each listening position, which has at least one additional loudspeaker (30a, 30d) or an additional loudspeaker array, the additional loudspeaker system having a structure-borne sound loudspeaker 35b, 35d in a footwell assigned to the listening position, in a seat assigned to the listening position and/or in a headrest assigned to the listening position tze is arranged and / or is mechanically coupled to the seat assigned to the listening position.

According to a second aspect with reference to the first aspect, the loudspeaker system 1, 1', 1'' being designed in order, with the aid of the plurality of electroacoustic sound transducers 20a-20h, 52a-52h, 54a-54i of the loudspeaker array 20, 50, 60, 70, 80, 90 to operate acoustic beam forming to form the sound cones 22a-22d, 22aL, 22aR.

According to a third aspect with reference to the first or second aspect, in the loudspeaker system 1, 1', 1'', the loudspeaker array 20, 50, 60, 70, 80, 90 or the sound outlet 94 of the loudspeaker array 20, 50, 60, 70, 80, 90 in a headliner of the vehicle, the center console of the vehicle, the dashboard of the vehicle or the parcel shelf of the vehicle.

According to a fourth aspect with reference to at least one of the first, second or third aspect, in the loudspeaker system 1, 1', 1" a distance between the loudspeaker array 20, 50, 60, 70, 80, 90 or the sound outlet 94 of the Loudspeaker arrays 20, 50, 60, 70, 80, 90 and all of the listening positions 12a-12d or a subset of all listening positions 12a-12d with a deviation of +/- 30% be the same.

According to a fifth aspect with reference to at least one of the first to fourth aspects, in the loudspeaker system 1, 1', 1'', the loudspeaker array 20, 50, 60, 70, 80, 90 or the sound outlet 94 of the loudspeaker array 20, 50, 60, 70, 80, 90 be arranged centrally between at least two of the listening positions 12a-12d in the vehicle interior 10.

According to a sixth aspect referring to a previous aspect, in the loudspeaker system 1, 1', 1'', the additional loudspeaker system can be closer to the user than the loudspeaker array 20, 50, 60, 70, 80, 90 or the sound outlet 94 of the loudspeaker -Arrays 20, 50, 60, 70, 80, 90.

According to a seventh aspect with reference to a previous aspect, in the speaker system 1, 1', 1", the additional speaker system can be installed in a seat assigned to the listening position, in a position assigned to the listening position of the A pillar, the B pillar, the C pillar and /or the headliner and/or be arranged in a headrest assigned to the listening position.

According to an eighth aspect with reference to a previous aspect, the additional loudspeaker system in the loudspeaker system 1, 1', 1" can be designed to output a sound 32al, 32d, 36b, 36d in such a way that a large part of the sound 32al, 32d, 36b, 36d with respect to the further one of the listening positions 12a-12d arrives at the corresponding listening position 12a-12d.

According to a ninth aspect referring to a previous aspect, in the loudspeaker system 1, 1', 1'', the auxiliary loudspeaker system may be arranged closer to one ear of the user than to the other ear of the user.

According to a tenth aspect with reference to the ninth aspect, the loudspeaker array 60, 70, 80 can comprise a further plurality of third electroacoustic sound transducers.

According to an eleventh aspect with reference to a previous aspect, the loudspeaker system 1, 1′, 1″ can be designed with the aid of the additional loudspeaker system in order to reproduce stereo for each listening position 12a-12d or to reproduce mono with a local level boost.

According to a twelfth aspect with reference to at least one of the first to eleventh aspects, the loudspeaker system 1, 1', 1" can be designed to, with the aid of the plurality of electroacoustic sound transducers 20a-20h, 52a-52h, 54a-54i of the Loudspeaker arrays 20, 50, 60, 70, 80, 90 to operate acoustic beam forming to form the sound cones 22a-22d, 22aL, 22aR.

According to a thirteenth aspect with reference to at least one of the first to twelfth aspects, the loudspeaker system 1, 1′, 1″ can be designed to 12d to generate at least two sound lobes 22aL, 22aR or a stereo sound lobe; and/or wherein the loudspeaker system 1, 1', 1" can be designed to virtually position sound sources in the room 10 using transfer functions which emulate psychoacoustic effects .

According to a fourteenth aspect with reference to a previous aspect, in the loudspeaker system 1, 1', 1'' the beam forming can be based on the direct and/or indirect sound reproduction in relation to the user.

According to a fifteenth aspect with reference to a previous aspect, in the loudspeaker system 1, 1', 1" a sound pressure level and/or a radiation direction per beam assigned to a listening position can be selected such that the sound pressure level at other listening positions 12a-12d after absorption and/or reflection is below a listening threshold.

According to a sixteenth aspect with reference to a previous aspect, the loudspeaker system 1, 1', 1" can be designed to operate beam-forming taking into account a seat adjustment or a head position of the user at the listening position and/or the sound beams 22a-22d, 22aL , 22aR to track depending on the seat adjustment and / or the head position of the user.

According to a seventeenth aspect with reference to at least one of the first to sixteenth aspects, the loudspeaker system 1, 1′, 1″ can comprise a controller which is designed to individually control the electroacoustic sound transducers 20a-20h, 52a-52h, 54a-54i.

According to an eighteenth aspect, referring to a previous aspect, a loudspeaker array 60, 70, 80 can have the following features: a plurality of first electroacoustic sound transducers 54a-54i arranged on a first line; and a plurality of second electro-acoustic transducers 52a-52h having the first line or a line parallel to the first line, with an average distance d _B between the first electroacoustic sound transducers 54a-54i being smaller than an average distance d _A between the second electroacoustic sound transducers 54a-54i.

According to a nineteenth aspect, a loudspeaker array 70 can have the following features with reference to a previous aspect: a plurality of first electroacoustic sound transducers 54a-54i, which are arranged in a first planar region 70i; and a plurality of second electro-acoustic sound transducers 52a-24h arranged in the first planar area 70a, wherein an average density of the first electro-acoustic sound transducers 54a-54i is smaller than an average density of the second electro-acoustic sound transducers 52a-52h.

According to a twentieth aspect, referring to at least one of the eighteenth or nineteenth aspect, in the speaker array 60, 70, at least two of the first electro-acoustic transducers 54a-54i can be framed by two of the second electro-acoustic transducers 52a-52h.

According to a twenty-first aspect with reference to at least one of the eighteenth to twentieth aspects, the first electroacoustic sound transducers 54a-54i can be designed in the loudspeaker array 20, 50, 60, 70, 80, 90 to define a first frequency range by a first center frequency reproduce, and the second electroacoustic sound transducer 52a-52h be designed to reproduce a second frequency range defined by a second center frequency, the first center frequency being higher than the second center frequency.

According to a twenty-second aspect, a loudspeaker array 90 can have the following features: a plurality of electroacoustic sound transducers 52a-52h, which are coupled to first sound guides 92a-92h for sound output in a first area 56, each sound guide 92a-92h including a sound outlet opening 94 , the plurality of sound outlet openings 94 being arranged such that an average distance d _S between the sound outlet openings 94 is smaller than a possible average distance d _A between the electroacoustic sound transducers 52a-52h arranged next to one another.

The embodiments described above are merely illustrative of the principles of the present invention as defined in the appended claims. It is understood that modifications and variations to the arrangements and details described herein will occur to those skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented in the description and explanation of the embodiments herein.

Claims (10)

1. A loudspeaker system (1, 1', 1") in a vehicle, comprising:

   a plurality of electroacoustic sound transducers (52a-52h) forming a loudspeaker array (20, 50, 60, 70, 80, 90) and coupled to first sound guides (92a-92h) for sound output in a first area (56), wherein each sound guide (92a-92h) includes a sound outlet opening (94),

   wherein the plurality of sound outlet openings (94) are arranged such that an average distance (ds) between the sound outlet openings (94) is smaller than a possible average distance (d_A) between the juxtaposed electroacoustic sound transducers (52a-52h);

   wherein the loudspeaker system (1, 1', 1") includes a controller configured to individually control the electroacoustic sound transducers (20a-20h, 52a-52h, 54a-54i) to perform, with the help of the plurality of the electroacoustic sound transducers (20a-20h, 52a-52h, 54a-54i) of the loudspeaker array (20, 50, 60, 70, 80, 90), acoustic beamforming for forming the sound beams (22a-22d, 22aL, 22aR); or

   wherein the loudspeaker array (20, 50, 60, 70, 80, 90) or the sound outlet openings (94) of the loudspeaker array (20, 50, 60, 70, 80, 90) is/are arranged in a roof lining of the vehicle, the center console of the vehicle, the dashboard of the vehicle or the rear shelf of the vehicle.
2. The loudspeaker system (1, 1', 1") according to claim 1, wherein a distance between the loudspeaker array (20, 50, 60, 70, 80, 90) or the sound outlet openings (94) of the loudspeaker array (20, 50, 60, 70, 80, 90) and all of the listening positions (12a-12d) or a subset of all listening positions (12a-12d) is the same, with a deviation of +/- 30%.
3. The loudspeaker system (1, 1', 1") according to any of the preceding claims, wherein the loudspeaker array (20, 50, 60, 70, 80, 90) or the sound outlet openings (94) of the loudspeaker array (20, 50, 60, 70, 80, 90) is/are arranged centrally between at least two of the listening positions (12a-12d) in the vehicle interior (10).
4. The loudspeaker system (1, 1', 1") according to any of claims 1 to 3, wherein beamforming is based on direct and/or indirect sound reproduction with regard to the user; and/or

   wherein a sound pressure level and/or radiation direction per beam allocated to a listening position are selected such that the sound pressure level is below a listening threshold at other listening positions (12a-12d) after absorption and/or reflection; and/or

   wherein the loudspeaker system (1, 1', 1") is configured to perform beamforming while considering a seat adjustment or a head position of the user at the listening position and/or to track the sound beams (22a-22d, 22aL, 22aR) in dependence on the seat adjustment and/or the head position of the user.
5. The loudspeaker system (1, 1', 1") according to any of the preceding claims,
   wherein the first center frequency is higher than the second center frequency,
6. A loudspeaker system (1, 1', 1") for a vehicle, comprising:

   a loudspeaker array (20, 50, 60, 70, 80, 90) including a plurality of electroacoustic sound transducers (20a-20h, 52a-52h, 54a-54i) that can be controlled individually, such that a user-specific audio signal can be reproduced for different users at different listening positions (12a-12d) in a vehicle interior (10) of the vehicle via the plurality of electroacoustic sound transducers (20a-20h, 52a-52h, 54a-54i),

   wherein the loudspeaker array (20, 50, 60, 70, 80, 90) or a sound outlet (94) of the loudspeaker array (20, 50, 60, 70, 80, 90) is arranged between at least two of the listening positions (12a-12d) in the vehicle interior (10),

   wherein the loudspeaker system (1, 1', 1") includes, per listening position, at least one additional loudspeaker system comprising at least one additional loudspeaker (30a, 30d) or an additional loudspeaker array,

   wherein the additional loudspeaker system comprises a structure-borne sound loudspeaker (35b, 35d) that is arranged in a foot space allocated to the listening position, in a seat allocated to the listening position and/or a headrest allocated to the listening position and/or that is mechanically coupled to the seat allocated to the listening position,

   wherein the loudspeaker system (1, 1', 1") includes a loudspeaker array (90), comprising:
   a plurality of electroacoustic sound transducers (52a-52h) coupled to first sound guides (92a-92h) for sound output in a first area (56), wherein each sound guide (92a-92h) includes a sound outlet opening (94),

   wherein the plurality of sound outlet openings (94) are arranged such that an average distance (dS) between the sound outlet openings (94) is smaller than a possible average distance (dA) between the juxtaposed electroacoustic sound transducers (52a-52h).
7. The loudspeaker system (1, 1', 1") according to claim 6, wherein the additional loudspeaker system is closer to a user than the loudspeaker array (20, 50, 60, 70, 80, 90) or the sound outlet (94) of the loudspeaker array (20, 50, 60, 70, 80, 90).
8. The loudspeaker system (1, 1', 1") according to any of claims 6 to 7, wherein the additional loudspeaker system is configured to output sound (32al, 32d, 36b, 36d) such that, with regard to the further listening positions (12a-12d), a large part of the sound (32al, 32d, 36b, 36d) reaches the respective listening position (12a-12d).
9. The loudspeaker system (1, 1', 1") according to any of claims 6 to 8, wherein the additional loudspeaker system is arranged closer to one ear of the user than to the other ear of the user; and/or
   wherein the loudspeaker array (60, 70, 80) includes a further plurality of third electroacoustic sound transducers.
10. The loudspeaker system (1, 1', 1") according to any of claims 6 to 9, wherein the loudspeaker system (1, 1', 1") is configured, with the help of the additional loudspeaker system, to reproduce stereo per listening position (12a-12d) or mono with local level increase; and/or

    wherein the loudspeaker system (1, 1', 1") is configured to generate, with the help of the plurality of the electroacoustic sound transducers (20a-20h, 52a-52h, 54a-54i), at least two sound beams (22aL, 22aR) or at least two stereo sound beams per listening position (12a-12d); and/or

    wherein the loudspeaker system (1, 1', 1") is configured to virtually position sound sources in space (10) by using transfer functions emulating psychoacoustic effects.

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