DE202020104557U1 - Device for use on acoustic transducers, acoustic transducers with the device and system using acoustic transducers and devices - Google Patents

Abstract

Device for use on at least one sound transducer (1), characterized in that the device has a transmission grating (hereinafter referred to as grating (G)) which is arranged at least in some areas in front of the sound transducer (1) and that the grating (G) has at least one having an acoustic element (4) which is arranged in the direction of propagation of the sound, the speed of propagation of the sound within the acoustic element (4) being greater than in air.

Description

The invention relates to a device for use with acoustic transducers, an acoustic transducer with the device and system using acoustic transducers and is used in particular for loudspeakers and microphones to improve the sound quality.

Sound, music and speech are currently reproduced by electrically amplifying recordings or microphone signals and making them "audible" with sound transducers. The technology for this is more or less complex - depending on the quality requirements.

In the simplest case, the sound transducers are already built into the product (entertainment and communications technology). When it comes to high-quality reproduction, transducers are set up separately and precisely aligned as the end of an audiophile chain.

All acoustic sound sources such as dynamic loudspeakers, acoustic transducer systems as well as surface sound sources for sound, music and speech reproduction such as loudspeakers (broadband, one-way and multi-way systems), horn systems, bending wave converters, radial radiators and electrostats are understood as sound transducers. Also included are bass or sound reflex ports and sound reflectors.

The technology described is for the most part installed in rooms. The acoustics of the listening room have a negative impact on the quality of hearing.

According to the state of the art, attempts are made to use room acoustics to reduce the impairment caused by the listening room. This takes place in the room with absorbers in the form of, for example, carpets, foam, curtains or the like, by means of diffusers in the form of rough surfaces, wooden and plastic blocks, finely to coarsely structured stone surfaces, shelves, or by means of bass traps, in particular Helmholtz resonators, foam or similar.

Such devices are attached freely in the room or on walls, ceilings, windows and doors or on the floor. For physical reasons, they often have to be large, heavy, thick and have a wide variety of surfaces. Mostly they disturb a comfortable living environment.

The following publications show the current state of the art for making sound improvements directly on the transducer (chassis). The basic idea behind it is: the better the acoustic signal from the transducer, the better what is heard from the sum of direct sound + room reflections.

The pamphlet DE 26 49 771 C3 shows a loudspeaker in which individual elements, so-called sound conduction rods with a high speed of sound, are inserted into the membrane. A mixture of approximately 60% graphite and 40% epoxy resin is disclosed as the material for these elements.

The aim is to avoid resonance of the membrane in order to make damping superfluous.

The pamphlet DE 694 27 942 T2 describes membrane-integrated molded bodies for loudspeakers, which can be made of diamond material. The membrane portion of the fabric substrate has a polymer resin which is at least partially impregnated therein to impart rigidity to the membrane portion.

It is contemplated that preferably predetermined portions of the woven fabric substrate are coated or impregnated with polymer resins or other agents.

The pamphlet US 2011/0222722 A1 contains a loudspeaker which has sound conductors in the edge area, the speed of which is higher than in the air. The aim is to smooth the wavefront of the loudspeaker.

From the pamphlet DE 100 49 744 A1 a dynamic loudspeaker system with a diaphragm made of polycrystalline diamond is known. Since conventional loudspeaker diaphragms are not infinitely stiff and deform to a greater or lesser extent with impulsive excitation, this leads to certain parts of the diaphragm moving out of phase with the stimulating coil from a certain break-up frequency, which results in audible, linear and non-linear distortions that impair the sound quality of high-quality loudspeaker systems . The use of a diamond membrane is said to reduce this effect.

Due to the great hardness of the synthetic diamond molded part used here, increased dimensional stability of the loudspeaker membrane is achieved. Due to the extremely high speed of sound propagation in the diamond lattice, the break-up frequency F (br) continues to be shifted far into the ultrasonic range and can no longer have a disadvantageous effect in the audible range.

It is disadvantageous that retrofitting to an existing loudspeaker system is not possible or only possible at considerable expense in terms of replacing the membranes.

The object of the invention is to develop a device for use on acoustic transducers, an acoustic transducer with the device and a system using acoustic transducers and devices, which have a simple structural design, improve the hearing quality of the sound waves emitted by the transducers and the the acoustic influence of a listening room on audio playback is reduced.

This problem is solved with the features of the 1st, 16th and 17th claims.

Advantageous refinements result from the subclaims.

According to the invention, a device for use on at least one sound transducer has at least one transmission grating (hereinafter referred to as grating) which is arranged at least in some areas in front of a sound transducer, the grating having at least one acoustic element which is arranged in the direction of propagation of the sound, the The speed of propagation of the sound within the acoustic element is greater than in air. The exiting sound of the sound transducer hits the grille and the at least one acoustic element at least in some areas, the sound exiting from the sound transducer and striking the acoustic element being significantly accelerated in the area of the acoustic element compared to the surrounding air by means of the acoustic element.

This is due to the different speed of propagation of sound in different media. Sound is accelerated in a solid medium compared to a gaseous medium, since the speed of sound propagation in the solid medium is greater than in air.

A sound transducer converts acoustic signals as alternating sound pressures into electrical signals (microphone) or an electrical voltage into acoustic signals (loudspeakers).

The sound transducer is preferably designed here in the form of a loudspeaker or microphone.

Instead of arranging the device in front of a sound transducer, it can also be arranged in front of a sound reflector.

The acoustic element can be arranged with differently designed holding devices in front of the sound transducer or sound reflector.

The device preferably has at least one holding device for receiving at least one acoustic element of the grille.

The holding device preferably has one or more openings in which the acoustic element (s) are arranged. The openings can be variably equipped with acoustic elements so that the sound in the acoustic elements is accelerated in the direction of sound propagation compared to the ambient air.

The transmission grating is thus formed for the first time by the air in which the "holes" are arranged in the form of the acoustic elements in which the sound emitted by the sound transducer is accelerated compared to the air and thus a "lead" in the area of each acoustic element in comparison to the speed of sound propagation in the ambient air.

Specific zones of the device can optionally and specifically be provided with such acoustic elements by means of one or more holding devices, or not.

The holding device (s) should not offer any resistance to the sound emitted by the sound transducer. That is why they are provided with large openings to make them as sound permeable as possible.

In order to keep the resistance of the grids and their influence on the reproduction quality in the case of sound emission low, the grille preferably has a curvature, whereby it can be arranged in a curved manner around the sound transducer. Preferably, the grille is hemispherical with half the circumference of the diameter of the covered chassis. Furthermore, flat arches or a front-parallel cover of the chassis are also possible.

For example, the holding device can have a curvature and thus be arranged bent around the sound transducer.

In a further embodiment, the device can have a plurality of holding devices lying one behind the other, which can be arranged in front of a sound transducer. This results in cascading grid structures. Furthermore, the holding devices and / or the acoustic elements received therein can be designed to be displaceable relative to one another for fine adjustment. Alternatively, it is also possible for only individual acoustic elements to be displaceable on the holding device.

The holding device can also be designed in the form of a grid,

For a further optimization of the sound quality, the device can be rotatably and / or tiltably mounted. Thus, by means of the holding devices and the acoustic elements, the radiation behavior of the chassis or the spatial conditions can be addressed.

The area of the cover by means of the device in front of the sound transducers and / or sound reflectors can vary and is possible from a complete cover to a partial adaptation. It can also be a star-shaped configuration, combined from and with grid and column elements. In order to achieve optimal sound quality, the device is specially adapted to the respective sound transducer in the form of a tweeter, mid-range speaker, surface or radial radiator including bass reflex openings, etc.

In this case, the device should advantageously cover the sound transducer or the sound reflector at least partially or completely.

In an advantageous embodiment, the device has one or more holding devices, by means of which holding structures of different shape place the acoustic elements variably in front of the sound transducers or the sound reflectors.

Compared to air, the acoustic elements have at least 10 times the propagation speed of the sound and consist in particular of glass, quartz or diamond.

The acoustic elements arranged in the grid are preferably made of diamond, since diamond has a speed of sound of 18,000 m / s (at 20 ° C) many times higher than air (343 m / s at 20 ° C), so that the sound emitted through the acoustic elements are greatly accelerated compared to the ambient air.

These acoustic diamond elements are designed in the form of crystals, flat, concave or convex shaped wafers, lenses, cut diamonds or plates in all conceivable geometrical designs and material thicknesses. Artificial or natural diamond can be used.

The holding device is preferably made of metal, wood, plastic or glass, but combinations of the usual materials can also be present.

The holding device with the acoustic elements accommodated therein can have several configurations, this first configuration consisting of lattice-like bars or reshaped perforated sheets or expanded metal grids. Alternatively, the holding device can be made in the form of perforated plates or freely three-dimensional structures.

The openings for the acoustic elements arranged in the holding device are preferably matched to the respective grain plates, crystal or wafer sizes. They can also be funnel-shaped and contain threads in order to fix the acoustic elements in them in a stable and variable manner. If the holding device is made of ferromagnetic material, e.g. iron, the acoustic elements can also be attached to it by means of magnetically designed mounts, which are optionally funnel-shaped on one or both sides.

According to the invention is also a sound transducer with the device described above.

• Trifft Schall mit einer Wellenlänge auf einen Spalt, die viel größer ist, als der Spalt, wird er am Spalt gebeugt und es entsteht eine neue eigenständige Schallquelle. Das Gleiche passiert bei einem „kurzen Spalt“ wie zum Beispiel bei einem Loch. Setzt man mehrere Löcher nebeneinander, entsteht ein Gitter. Trifft der Schall auf ein Gitter, entstehen viele punktförmige Schallquellen, die sich in einiger Entfernung vom Gitter zu einer ebenen Welle vereinigen.

The function of the device can be described as follows:

• If sound hits a gap with a wavelength that is much larger than the gap, it is bent at the gap and a new, independent sound source is created. The same thing happens with a “short gap” such as a hole. If you put several holes next to each other, a grid is created. If the sound hits a grid, many point sources of sound are created, which combine to form a plane wave at some distance from the grid.

In the solution according to the invention, the acoustic elements with a material that has a higher speed of propagation of the sound compared to air, so to speak, represent the holes in the ambient air. Through these "high-speed holes", the incident sound is accelerated compared to the ambient air and achieves a " Forward ‟to the sound propagating in the air.

In addition to this finding, the preferred material of the acoustic element in the form of diamond conducts sound about 52 times faster than air. This means that incoming sound travels through the diamond at 52 times the speed of sound.

If a grid of air and acoustic elements is inserted between a sound source, for example in the form of a sound transducer and listener, a person or a microphone, the output signal of the sound source, e.g. the sound transducer, becomes a sound component that passes directly through the ambient air as well as a sound component through the acoustic elements accelerated sound component divided.

This happens because the diamonds in the ambient air become "high-speed holes" for sound, similar to holes in a soundproof wall. This proportion of sound overtakes the proportion of sound that propagates through the air at the simple speed of sound. Each acoustic element, in particular each diamond, becomes its “own” sound source with a “leading” signal in accordance with the physical phenomena on a transmission grid. Due to the special crystal shapes of the acoustic elements, this sound component can also be scattered several times.

In relation to the invention, it can be determined that if the sound source, in particular a sound transducer, sends through a transmission grating, the accelerated sound component from the preferably "diamond grating" = acoustic elements made of diamond held in the ambient air by a holding device hurrying ahead as an exact copy ( n) hits the listener. Shortly afterwards, the original sound passing through reaches the listener with a time delay.

The signals from the sound transducer / the sound source thus reach the listener several times in quick succession. As a result, the original signals heard several times are picked up by the human hearing system much more intensely than just the individual original signal. Disturbing reflections from the room have a much lower chance of penetrating the listener's awareness (Haas effect).

With the layer thickness and the area or the grain size of the diamond, the time difference between leading and normally passing sound can be influenced.

A sound that is perceived as pure, clean and holographic can be “worked out” in a targeted manner.

The invention also relates to a system made up of several sound transducers in combination with several devices according to the invention.

These aforementioned effects are reinforced by the system according to the invention in that further sound transducers provided with such grids are set up in the room. These are set up diagonally across from the respective front channels (left, right, center, etc.) behind the listener and aligned precisely with the front loudspeakers. If the signal from the "original channels" (left, right, middle, etc.) is played in such a way that its volume just drowns out the room reflections, the room reflections are no longer perceived (the existing room acoustics are artificially played over with the original signal actually desired , the Haassche effect also works here). If the signals are also delayed somewhat (phase shift), this changes the acoustically the virtual listening room.

By using diamonds between sound sources and an acoustic transducer in the form of a microphone and a recording source, bundling, scattering and focusing settings are possible.

The influence of the acoustics of the listening room is very strongly suppressed during listening by the system according to the invention. This significantly improves the listening quality of sound, music and speech reproduction.

It is advantageous that the system according to the invention can also be easily retrofitted to existing acoustic systems.

• 1 eine schematische Darstellung der Anordnung der Vorrichtung in einem Hörraum,
• 2 Ausgestaltungen von Varianten a bis d des Halteapparates in einer Vorderansicht,
• 3 Ausgestaltungen des Halteapparates der Varianten a bis d gemäß 2 in einer Seitenansicht,
• 4 drei hintereinander angeordnete Gitter,
• 5 das akustische Element mit und ohne Fassungen,
• 6 eine Frontalansicht der akustischen Elemente,
• 7 ein asymmetrisch vor einem Lautsprecher angeordnetes Gitter,
• 8 Ausschnitt eines Halteapparates, der ein Grundelement und daran angeordnete zueinander parallele Streben aufweist,
• 9 eine Vorrichtung mit einem Halteapparates 2 mit kreisförmigem Grundelement und oben biegsamen Streben,
• 10 System mit mehreren akustischen Wandlern und Vorrichtungen.

The invention is explained in more detail below using an exemplary embodiment and associated drawings. Show it:

• 1 a schematic representation of the arrangement of the device in a listening room,
• 2 Refinements of variants a to d of the holding device in a front view,
• 3 Refinements of the holding apparatus of the variants a to d according to 2 in a side view,
• 4th three grids arranged one behind the other,
• 5 the acoustic element with and without sockets,
• 6th a front view of the acoustic elements,
• 7th a grille arranged asymmetrically in front of a loudspeaker,
• 8th Section of a holding device which has a base element and mutually parallel struts arranged on it,
• 9 a device with a holding apparatus 2 with a circular base element and flexible struts at the top,
• 10 System with multiple acoustic transducers and devices.

In 1 a schematic listening room H is shown with a device according to the invention. In the center of the listening room H is a sound transducer 1 , in particular a loudspeaker or a bass reflex opening or a reflector is arranged. The schematically drawn sound transducer 1 can also consist of several sound transducers arranged differently in the room.

In front of the transducer 1 is a spaced arcuate and grid-like holding element in the direction of propagation of the sound 2 arranged, which of the one from the transducer 1 exiting sound is penetrated. The holding element 2 has openings arranged therein 3 on, in which at least partially an acoustic element 4th is arranged. The speed of propagation of the sound within the acoustic element 4th is higher than in air, so that the sound in the acoustic elements 4th towards the environment and the openings 3 in which there is ambient air is accelerated. This creates a kind of acoustic grid G made of airborne acoustic elements 4th formed in the air by the retaining element 2 are positioned in front of the transducer.

In the 2 and 3 are different configurations a to d of the holding apparatus 2 in a front view ( 2 ) and a side view ( 3 ) shown. According to the illustrations, the holding apparatus 2 be designed in the form of perforated plates or freely three-dimensional structures.

To optimize the sound quality, the device with the holding device 2 can be rotated and / or tilted. So can by means of the holding apparatus 2 the radiation behavior of the chassis or the spatial conditions are discussed.

The ones in the 2 and 3 shown lattice-shaped holding apparatus 2 are only exemplary, the holding apparatus 2 can also take on other forms and contours. For a better representation, the representation of an acoustic element within the holding apparatus has been made 2 waived.

4th shows a cascading structure of a holding apparatus 2 with several lattice-shaped components lying one behind the other 2.1 . The grid-shaped components 2.1 of the holding apparatus 2 are curved and arranged to one another in such a way that an opening in a horizontal line 3 a first component 2.1 behind a closed web of a second component 2.1 and following an opening 3 of a third component 2.1 of the holding apparatus 2 is arranged. This creates three acoustic grilles arranged one behind the other in the direction of sound propagation G educated. The parts 2.1 of the holding apparatus 2 however, they can also be arranged offset from one another in some other way. Also a straight design of the components 2.1 or the holding apparatus 2 is possible.

In one or more openings 3 the grid-shaped and, for example, three-dimensional, in particular spherical segment-shaped, curved components 2.1 of the holding apparatus 2 acoustic elements (not shown here) can be arranged.

According to 5 is an acoustic element 4th shown in longitudinal section in four configurations a) to d). Viewed from left to right, a) is first an acoustic element 4th shown, through which the sound can be transmitted and accelerated in the direction of the arrow (preferably from one direction). In the illustration b) arranged next to it, the sound is transmitted through the acoustic element in the direction of the arrow 4th directed, the acoustic element 4th in one version 6th is arranged.

The version 6th can also be designed in the form of a double-sided or single-sided horn in accordance with the two right-hand representations c) and d). Thereby the sound is before penetrating the acoustic element 4th bundled and, in the case of the double-sided horn, similar to a horn, connected to the room acoustics after penetration.

A top view of the acoustic element 4th is in 6th shown. The acoustic element 4th becomes of a version 6th enclosed or is in a version 6th arranged. The version 6th can according to 5 be designed differently and bundle the sound or connect it to the room acoustics.

It is possible to change the version 6th to be designed as a ring magnet and to arrange the acoustic element in it, so that the socket 6th with the acoustic element 4th can be attached to any position of a holding device made of ferromagnetic material (e.g. iron).

According to 7th is in front of a transducer 1 in the form of a loudspeaker or a bass reflex opening or a reflector, a hemispherical lattice-like holding device 2 arranged. The holding apparatus 2 is asymmetrical in front of the transducer 1 arranged, the holding apparatus 2 here a wide and a narrow side next to the loudspeaker (sound transducer 1 ) or the loudspeaker (transducer 1 ) at different distances. The holding apparatus 3 has individual openings 3 on. In some of the openings 3 each is an acoustic element 4th brought in. This also creates an acoustic grating G educated

There are many other variants of holding devices 2 possible around one or more acoustic elements 4th to record.

The acoustic elements 4th can in permanent magnetic sockets 6th be arranged or the sockets of the acoustic elements are accommodated in permanent magnets, so that the acoustic elements 4th arbitrarily on one Holding apparatus 2 made of ferromagnetic material can be positioned.

8th shows an example of a section of a holding device 2 who is a basic element 2.2 has, which is only partially visible here in the cutout. At the basic element 2 extend two mutually parallel struts 2.3 made of a ferromagnetic material. On the two struts 2.3 is a version 6th fastened from a ring magnet, in the recess (not designated) the acoustic element 4th is arranged, this by magnetic attraction on the struts 2.3 is fixed.

With the magnetic socket 6th can the acoustic element 4th according to the two arrows shown freely on the struts 2.3 be moved. Fastening to non-magnetic materials by means of screw connections to the acoustic elements is also conceivable.

There can be several of the struts 2.3 circumferentially on a base element 2.2 be arranged.

In 9 is a device with a holding apparatus 2 shown, which is a lower circumferential closed here circular base element 2.2 has, on which upwardly flexible struts 2.3 connect, at the ends of which acoustic elements 4th are arranged. These can be fastened in sockets, not shown here, which are fastened to the free ends of the struts. The striving 2.3 can be bent freely into a desired position, what is here on a strut 2.3 is exemplified by dashed lines.

The aforementioned variants of the devices can be combined with one another as desired, or other structural variants of the holding devices can also be provided.

By means of suitable elements, the holding devices can be positioned in a fixed or adjustable position in front of a sound source, e.g. a sound transducer, in the form of a loudspeaker, a microphone and the like, or a sound reflector.

In 10 shows a loudspeaker arrangement in the listening room for suppressing the audibility of room reflections, which consists of a first pair of loudspeakers with loudspeakers L. , R. and a second pair of speakers with speakers L ' , R ' exist. Every speaker L. , R. , L ' , R ' is with a holding device 2 with acoustic elements 4th provided, which allow the effectiveness of the arrangement significantly.

The left and right speakers L. , R. of the first pair of speakers in front of the listener 5 send the left and right signals of the recording at the desired volume (classic stereophony playback).

The speaker R ' , L ' behind the phone 5 are reversed and aligned exactly to the diagonally opposite loudspeaker ( R ' on R and L ' on L. ). This means that the left channel behind the listener sends to the left front channel and vice versa. The speaker R ' and L ' also send the original signals of the recording, but with a reduced volume and, if necessary, a phase shift.

From those behind the phone 5 placed speakers R ' , L ' This means that room reflections are effectively influenced by the listener's perception 5 shielded by from the rear speakers R ' , L ' If necessary, original signals that have been changed in volume and phase can be played back into the listening room.

Due to this arrangement and the associated signal processing, "unclean" room reflections are superimposed by "clean" original signals. With the phase shift, the virtual size of the listening room can also be changed acoustically.

The effectiveness of the system according to the invention is based on the effects of the acoustic elements on the loudspeaker in the Haasschen effect, the precedence effect and the superposition (undisturbed superposition and amplification) of frontal waves.

The solution according to the invention creates a three-dimensional listening room. The spatial sound experience is retained even if a listener moves freely in a listening room, similar to wave field synthesis.

List of reference symbols

1

Transducer

2

Holding apparatus

2.1

curved components

2.2

Basic element

2.3

Striving

3

opening

4th

Acoustic element

5

Listener

6th

Version

G

Grid

L.

left speaker of the first speaker pair

R.

right speaker of the first speaker pair

L '

left speaker of the second speaker pair

R '

right speaker of the first speaker pair

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 2649771 C3 [0009]
• DE 69427942 T2 [0011]
• US 2011/0222722 A1 [0013]
• DE 10049744 A1 [0014]

Claims (17)

Device for use on at least one sound transducer (1), characterized in that the device has a transmission grating (hereinafter grating (G)) which is arranged at least in some areas in front of the sound transducer (1) and that the grating (G) has at least one having an acoustic element (4) which is arranged in the direction of propagation of the sound, the speed of propagation of the sound within the acoustic element (4) being greater than in air. Device according to Claim 1 , characterized in that the grating (G) has several acoustic elements (4). Device according to Claim 1 or 2 , characterized in that the device has at least one holding device (2) for receiving at least one acoustic element (4) of the grille (G). Device according to one of the Claims 1 until 3 , characterized in that the holding device (2) has one or more openings in which the acoustic element (s) (4) is / are arranged, wherein the opening (s) can be variably equipped with acoustic elements (4), so that in the sound propagation direction in zones after the acoustic element (s) (4), a sound acceleration can be achieved compared to the propagation of the sound in the air surrounding the acoustic elements (4). Device according to one of the Claims 1 until 4th , characterized in that the holding device has a curvature and can be arranged in a curved manner around the sound transducer (1). Device according to one of the Claims 1 until 5 , characterized in that the device has several holding devices (2) lying one behind the other with acoustic elements (4) which can be arranged in front of the sound transducer (1). Device according to one of the Claims 1 until 6th , characterized in that the device is rotatably and / or tiltably mounted. Device according to one of the Claims 1 until 7th , characterized in that the device covers the sound transducer (1) at least partially to completely. Device according to one of the Claims 1 until 8th , characterized in that the holding device (2) is arranged in front of the sound transducer (1) in the direction of sound propagation, the device having at least one holding device (2), by means of which acoustic elements (4) can be variably placed in front of the sound transducer (1). Device according to one of the Claims 1 until 9 , characterized in that the acoustic element (4) has at least 10 times the propagation speed of the sound compared to air and in particular consists of glass, quartz or diamond. Device according to one of the Claims 1 until 10 , characterized in that the acoustic element (4) is designed in the form of flat, concave or convex shaped wafers, lenses, cut diamonds or plates in all conceivable geometrical designs. Device according to one of the Claims 1 until 11 , characterized in that the holding device (2) is made of metal, wood, plastic or glass. Device according to one of the Claims 1 until 11 , characterized in that the holding device (2) is designed in the form of strung rods, perforated plates, in the manner of a grid or free three-dimensional structures. Device according to one of the Claims 1 until 13th , characterized in that openings in the holding device (2) are adapted to the shape of the acoustic elements (4), and that the acoustic elements (4) are detachably or non-detachably received in the holding device (2). Device according to one of the Claims 1 until 14th , characterized in that the holding device (2) can be attached directly to an existing mounting option for the sound transducer (1) and / or that the acoustic element (4) is arranged in a holder (6) and is attached to the holding device (2) with this. Sound transducer, comprising a device according to Claim 1 . System with sound transducers according to Claim 16 characterized in that the sound transducers (1) are set up diagonally to one another.

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