DE202013104545U1 - Device for active and / or passive influencing of room acoustics - Google Patents

Abstract

Device (1) for active and / or passive influencing of the room acoustics, comprising at least one sound absorber (2) and at least one sound transducer (3).

Description

The invention relates to a device for active and / or passive influencing of the room acoustics.

The acoustics of interior spaces are determined by superimposed sound fields consisting of direct sound emitted by sound sources and by diffuse sound produced by direct sound reflected at the boundary surfaces of the room. Depending on the use of space, measures to improve the acoustics are required, whereby the measures are also dependent on the use of space in addition to the shape and the equipment of the room. For example, in lecture halls, conference halls and meeting rooms, a high degree of speech intelligibility is required, and in music halls, the aim is to achieve a sound acoustical quality that is as homogeneous as possible.

From the DE 10 2009 007 891 A1 is a multi-layer porous porous sound absorber known. Such absorbers have a passive action principle, whereby no control or the like is required. The active principle of an open porous absorber based on the absorption of sound, wherein the air particles are excited in the pores of the absorber to vibrate and thereby be braked by contact with the porous structure. The sound energy is converted into heat energy. Such sound absorbers can be integrated into adjacent boundary surfaces of the room or retrofitted. In this case, it is particularly conceivable to mount the absorber as a ceiling sail suspended under a ceiling.

The invention has for its object to develop a device for active and / or passive influencing the room acoustics, which in addition to the sound absorption allows further possibilities of influencing the room acoustics.

This object is achieved with the features of claim 1. In advantageous embodiments, the dependent claims relate.

To achieve the object, the device for active and / or passive influencing of the room acoustics comprises at least one sound absorber and at least one sound transducer. The sound transducer comprises at least one loudspeaker for sounding the room. Depending on the requirements, the sound transducer can be modified with regard to the emission characteristics and the achievable volume. The sound transducer extends the possibility of the device in addition to the integrated sound absorber to improve the room acoustics through active sound.

In addition to a passive sound absorber, an active sound absorber may additionally or alternatively be provided. Active sound absorbers comprise a sensor for detecting the sound acting on the absorber and a sound source whose frequency is chosen so that the incoming unwanted sound is eliminated or converted.

The device can be designed in many ways, wherein in particular the plate-shaped configuration is advantageous. Such plate-shaped devices can simultaneously act as partitions, as well as mobile partitions. In this case, the facilities may be floor-standing or ceiling-mounted. Furthermore, plate-shaped devices, in particular in interaction with a pleasing optical design can be used as murals or as ceiling canopies.

In another advantageous embodiment, the device is designed as a cube or cuboid. Such devices are particularly suitable for use as free-standing elements, in particular for the subsequent improvement of the room acoustics.

In addition to the sound absorber and the transducer further elements can be integrated into the device. The device may comprise a cooling and / or heating component. For example, the device can be configured with a tube system, which can carry cold and / or hot water and thus air-conditioned the room. This embodiment is particularly suitable for the subsequent air conditioning of rooms, especially rooms or offices. Thus, the device also allows for retrofitting both an improvement of the room acoustics and an improvement of the indoor environment.

The integration of lighting is also conceivable. In order to be able to take into account the basic idea of a design of the device which is as flat as possible, an arrangement of LED lamps in the device is particularly advantageous in this context. This could be coupled by means of a control technique with the sound transducers, so as to allow an adjustment of the lighting depending on the type of sound. The control technique may also be arranged in the device.

It is also conceivable to provide the device with a scenting device. Thus equipped, the device can serve in addition to the improvement of the room acoustics and, where appropriate, the room climate and, where appropriate, the lighting also for room scenting. For this purpose, the device has a reservoir for storing a fragrance, a device for dispensing the fragrance, for example by evaporation or spraying and a control device for controlling the amount and the time.

The sound absorber may comprise at least one porous material. In such sound absorbers, the sound penetrates into the pores of the material, wherein the air particles are excited in the pores to vibrate and thereby be braked by contact with the porous structure. The sound energy is converted into heat energy. Porous sound absorbers have a high effectiveness over a wide frequency spectrum. Porous materials are available in a wide variety. Conceivable materials are foam, plaster systems, granules. Another and preferred material group is formed from the fiber material. Such fiber material may include textiles such as cotton, nonwoven fabric with synthetic fibers and / or mineral wool. Preferably, the choice of material is made such that the sound absorber emits no or only a very small amount of hazardous substances such as formaldehyde. This is the case in particular with a porous material made of nonwoven fabric.

The sound absorber may be formed in multiple layers, wherein in the aforementioned sound absorber layers can be combined with porous material, in particular fiber material with different density. The combination of the layers of different volume weight is preferably carried out in sandwich construction, since in this embodiment results in a homogeneous sound absorption. A preferred sound absorber comprises two thinly formed layers of porous material with a high density, between which a layer of low density with porous material thick compared to the two outer layers is arranged. The thinly formed layers cause a sound absorption in the high-frequency range and the thin layer causes a sound absorption in the low-frequency range. Preferably, the individual layers are glued or laminated together. For this purpose, the layers can be connected to one another by means of an adhesive layer

The sound absorber may be provided in sections on one or both sides with recesses in order to record the transducer or the can. If the sound transducer is covered by the sound absorber on a main side, directed radiation of the sound at high frequencies results only in one main side.

The sound absorber may comprise a plate-shaped element. Such an absorber may have a resonant-like oscillating surface element, for example a plate, a membrane or a film. In such sound absorbers, the surface element is arranged in front of a closed air volume, in which a porous material can additionally be arranged. By sound effect, the surface element is excited to vibrate, the amplitudes in the region of the natural frequency are particularly large. The kinetic energy of the surface element is converted into heat, thereby absorbing incident sound. The advantage of this sound absorber is the closed surface, which can also be used for design purposes and can be provided with graphics, for example.

In another embodiment, the plate-shaped element may be perforated. Basically, two principles of action are conceivable:

According to a first principle of action, the openings function as a Helmholtz resonator. Such resonators consist of an air column oscillating in the opening and a coupled closed air volume. The air column forms with the volume of air a vibrating spring-mass system. For sound absorption, the opening is designed so that the oscillating air column is braked. To dampen low-frequency sound, the element is provided with only a few openings, which open into a large volume of air.

After a second mode of action, the element is designed as a microperforated sound absorber. In this absorber, the element is provided with a plurality of blind holes. The diameter of the holes is chosen so that the acoustic boundary layer, the layer in which changes the rapid profile of the sound penetrating into the hole, extends over the entire hole cross-section. The existing in the holes air mass oscillates by sound excitation according to a spring-mass system comparable to a Helmholtz resonator. Microperforated sound absorbers have the advantage that the absorption effect is effective in a wide frequency range.

The sound absorber can be designed as a Schitzabsorber. A slot absorber comprises a first plate which is mounted spaced on a plane. The plane may be formed by a second panel or by a wall or ceiling of a room. Between the first plate and the plane, a porous material is arranged, wherein the porous material is preferably formed flat. Preferably, the porous material is formed of a fibrous material such as nonwoven or mineral wool. The porous material is preferably attached to the first plate. The first plate can by means of spacers, such as a Threaded rod screw assembly can be mounted above the plane at a fixed predetermined distance.

The principle of operation of a shock absorber is based on the fact that the sound to be absorbed penetrates into the gap between the first plate and the plane and is absorbed by the porous material.

The slot through which the sound to be absorbed penetrates, can be formed by the circumferential gap, which results from the spaced mounting of the first plate on the plane. Alternatively, it is conceivable to fix the first plate on a circumferential frame on the plane and to introduce at least one slot in the first plate, through which the sound to be absorbed can enter the volume between the first plate and plane.

The first plate is preferably made of a stable material, such as a metal plate.

The absorber performance of the sound absorber can be significantly increased again when several slot absorber are arranged in a cassette-shaped side by side, so that perpendicular to each other extending slots arise.

For the inventive effect of a slot absorber, however, it is not necessary to arrange a porous material in the space between the first plate and the plane. The advantageous absorber effect of the slot absorber is based on an interaction, in particular of inferences of the airborne sound entering through the slots and propagating within the closed volume of air. In this case, depending on the vote of the absorber absorption of the sound by mutual extinction of the sound waves or mutual amplification by resonance effect a sound amplification. As a result, the slot absorber is particularly effective for absorbing diffuse sound input. Another advantage of the slot absorber is that it has excellent absorption performance over a particularly wide frequency spectrum.

The slot absorber can be combined with one of the alternative absorbers described above, but is already inventive in its own right.

The sound absorber may comprise an absorber with an active principle. Such a sound absorber is preferably as a plate absorber, wherein a sensor detects the sound field and a control unit evaluates the detected by the sensor sound field and an actuator that controls the plate of the sound absorber oscillates in such a way that it vibrates to a greater extent, as in a pure passive resonating would be the case. It is advantageous that such a sound absorber has the same area a higher absorber performance. Furthermore, the sound absorber can be adjusted so that it is active only at certain times or under certain predetermined conditions. Another advantage is that an active sound absorber, in contrast to a passive sound absorber is repeatedly re-tuned and can be adjusted to new room conditions. Preferably, the active absorber is used for absorbing low-frequency signal components. In the device for active and / or passive influencing of the room acoustics, the aforementioned sound absorbers can also be integrated in combination. It is advantageous that the combined sound absorber covers a particularly wide frequency spectrum.

The sound transducer may comprise at least one speaker of the type of a point source, a line source and / or a surface source. If at least one sound transducer is designed as a loudspeaker of the type of a surface source, it is conceivable, in particular, for it to be designed as a bending wave transducer. Biegewellenwandler, also referred to as "Distributed Mode Loudspeaker (DML)", have a flat flexurally soft membrane, which is deformed for excitation. As a result, transversal waves are generated on the flat, thin membrane, which propagate uniformly in all directions on the membrane plane. The propagation results in an air vibration that is perceived as an acoustic signal.

Loudspeakers with a punctiform radiation characteristic are usually conventional electrodynamic loudspeakers. For point source type speakers, the sound propagates spherically from the speaker. However, the spherical propagation of the sound is limited depending on the installation situation, so that there is usually a more or less directional radiation of the sound. The advantage of such speakers is the small size in terms of diameter, or the width and the height. Specially shallow speakers of this type have two voice coils connected together by the diaphragm.

A loudspeaker with a line-shaped radiation characteristic is theoretically infinitely long and infinitely narrow according to the definition of a line. Such a sound source emits no spherical sound wave, but a cylindrical. From the prior art it is known to model such a sound source by a series arrangement of a plurality of loudspeakers with point source characteristic. However, this arrangement has the disadvantage that the plurality of Speakers cause a lot of interference. An advantageous loudspeaker of the type of line source has a membrane which has the greatest possible length at a small width. Furthermore, the membrane should be hung and excited so that it oscillates coherently over the entire length. For this purpose, the membrane is connected to a voice coil, which is arranged on a conductor track, which in turn is connected over the entire surface of the membrane. It is advantageous that results depending on the installation situation, a cylindrical radiation characteristic. Another advantage of this speaker is the low depth. Such speakers can be arranged to save space in the edge areas next to the area-trained sound absorber. It is conceivable that the speakers are arranged on both sides of the sound absorber or surround the sound absorber on all sides.

A loudspeaker with a flat emission characteristic has a membrane with a two-dimensional extent. There are basically two different configurations:

In an electrostat, the drive of the flat membrane takes place via an alternating field, wherein the electrically conductive membrane is arranged between two flat electrodes, for example perforated metal plates. A high DC voltage is applied to the foil, the audio signal being applied to the two electrodes, which in turn excite the diaphragm to vibrate. In such a sound source, the emitted sound field does not expand, so that a constant sound level results over the distance. This makes it possible to specifically sound the area in front of the device and to save areas next to the device from the sound system. In one or more devices arranged in parallel under a ceiling, one or more listening zones can be created which do not influence one another.

Another group of surface sources is formed by bending wave transducers. In these, a flat diaphragm is excited to chaotic vibrations. For this purpose, electromagnetic transducer elements are arranged on the membrane at a plurality of predetermined positions. Such a loudspeaker has a wide-angled and non-directional radiation behavior. The sound radiation is uniform and homogeneous. There is a uniform sound of the room.

The sound transducers designed as area sources can be arranged next to the sound absorbers if the sound radiation is to take place via both main sides. If the sound radiation is to take place only via one main side, the sound transducer can be arranged sandwiched over the sound absorber.

A particular advantage arises when the sound transducer is a speaker of the type of surface source, wherein the surface source is designed as a bending wave transducer. In this case, the membrane of the bending wave converter can fulfill a dual function. The membrane is connected to an actuator that excites the membrane to vibrate, which emits sound waves and the membrane is part of a loudspeaker. In addition, the membrane is part of the sound absorber, in particular a slot absorber. Thus, the membrane is both sound source and sound absorber. In order to improve the absorber effect, in particular with respect to high frequencies, a further sound absorber of sheet metal, wood or plastic can be arranged in front of the membrane.

A frame may be provided for receiving the sound absorber and the sound transducer. The frame is preferably made of metallic material, for example aluminum and is preferably rectangular. The frame accommodates the sound absorber and the sound transducer in its interior. Furthermore, the frame is provided with fastening means, such as eyelets or hooks and thus serves to attach the device to a wall or under a ceiling. Further, the frame may be provided with feet to place the device as a movable partition in a room can.

At least on one side, a replaceable cover can be provided. The cover is preferably made of a textile fabric. This can be provided with a graphic. By attachment points, which are provided on the frame, the cover can be attached by simple means and also removed again. Thereby, the shape of the device can be adapted by changing the graphics to respective requirements, for example special occasions, which are placed in the room in which the device is placed.

In the embodiment of the device according to the invention is advantageous that a combination of different embodiments of sound absorbers with different configurations of transducers is possible. This results in a combination element, which is customizable in a large area by project-specific requirements.

Some embodiments of the device according to the invention will be explained in more detail with reference to FIGS. These show, in each case schematically:

1 the device in section as a schematic diagram;

2 the device with linear sound transducers;

3 the device with a flat sound transducer;

4 a sound absorber with an active principle of action;

5 a device with a perforated element;

6 a device with a slot absorber;

7 a device with several slot absorbers.

1 shows a device 1 for active and passive influencing of room acoustics. The device 1 is plate-shaped and formed by a circumferential frame 9 limited, which is formed by a profile of metallic material. In the frame 9 is a sound absorber 2 and two as speakers 7 trained sound transducer 3 arranged. The device 1 is also covered by a cover 9 from a printed with a graphic textile fabric, which is stretched on the frame and fixed there. The frame 9 is with fasteners 10 , Here eyelets provided by the device under a ceiling can be suspended as ceiling sails or attached to a wall. In other embodiments, feet can also be provided by the device 1 can be placed free-standing in a room.

The sound absorber 2 is multi-layered and has a porous material in each of the layers 4 on. The density of the middle layer is less than the density of the two outer layers. The porous material 4 includes fiber material formed from an emission-free synthetic fiber nonwoven fabric. The layers of the sound absorber 2 are interconnected by means of an adhesive layer. The cover 9 facing layer of the sound absorber 2 has recesses 11 on, in which sound transducer, here speakers 7 are arranged of the type of a point source. The speaker 7 has two voice coils, which are interconnected by a membrane. This shows the sound transducer 3 a particularly small depth.

2 shows a device 1 for active and passive influencing of room acoustics. The device 1 is plate-shaped and formed by a circumferential frame 9 limited, which is formed by a profile of metallic material. In the frame 9 is a sound absorber 2 and four speakers designed as a sound transducer 3 arranged. The device 1 is also covered by a cover 9 from a printed with a graphic textile fabric, which is stretched on the frame and fixed there. The frame 9 is on the cover 9 opposite side with fasteners 10 here eyelets provided by the furnishings 1 can be mounted under a ceiling parallel to this.

The sound absorber 2 is multi-layered and has a porous material in each of the layers 4 on. The density of the middle layer is less than the density of the two outer layers. The porous material 4 includes fiber material formed from an emission-free synthetic fiber nonwoven fabric. The layers of the sound absorber 2 are interconnected by means of an adhesive layer. The cover 9 facing layer of the sound absorber 2 has recesses 11 on, in which sound transducer, here speakers 7 are arranged of the type of line source with a longitudinally extending membrane. Further, in the recess is a piping system 12 arranged for room air conditioning. As a result, depending on the temperature of the water flowing through the pipeline system, the device can function as a heating blanket and also as a cooling ceiling.

3 shows a device 1 for active and passive influencing of room acoustics. The device 1 is plate-shaped and formed by a circumferential frame 9 limited, which is formed by a profile of metallic material. In the frame 9 are a sound absorber 2 and a trained as a surface source transducer 3 arranged. The device 1 is also on both main sides by a cover 9 from a printed with a graphic textile fabric, which are stretched on the frame and fixed there. The frame 9 with fasteners 10 , Here eyelets provided by the device under a ceiling as a ceiling can be suspended suspended.

The sound absorber 2 is comprises a plate-shaped element 5 which one of the main page of the institution 1 assigned. The element 5 closes a room in which a porous material to improve the damping of the sound absorber 2 is arranged. To improve the absorber effect of the sound absorber 2 additionally a sensor 13 , a control unit 14 and an actor 15 so as to have an absorber 2 with active principle 6 to create, with the element 5 is controlled by the actuator and vibrated. It is also possible to use the element 5 to be perforated and provided with openings. On the other main page is a sound transducer 3 arranged on the type of a surface source, which extends through the frame 9 limited area extends. In this Design is the sound transducer 3 designed as an electrostat.

4 shows an example of a sound absorber 2 with active principle 6 , The sound absorber 2 points in addition to the element 5 a sensor 13 , a control unit 14 and an actor 15 on.

5 shows an example of a sound absorber 2 with a perforated element 5 ,

The 6 . 6a and 6b show a trained as slit absorber sound absorber 2 , The slot absorber has a first plate 16 which is spaced from a plane 17 is arranged and extends parallel to this. In this embodiment, the plane 17 formed by a second plate. Spacers extend out of the plane 18 vertically out, formed by threaded rods. The first plate 16 has corresponding openings through which the spacer can protrude. The attachment of the first plate 16 on the spacer 18 done by means of a threaded nut. Between the first plate 16 and the plane 17 is a porous material 19 arranged. The porous material 19 is made of a polyester fleece and on the first plate 16 attached, so that between porous material 19 and level 17 a gap results. In this embodiment, the first plate 16 from a sheet steel with 1 mm thickness, the porous material 19 made of a polyester fleece with 40 mm thickness. The distance between porous material 19 and level 17 is 10 mm. In this embodiment, an excellent absorber behavior over a wide frequency spectrum has resulted. The slot absorber designed in this way has a very high absorber power, in particular between 150 Hz and 500 Hz.

6a shows the sound absorber 2 according to 6 , where the first plate 16 with a circumferential edge 20 which is the porous material 19 at least partially covering. 6b shows the sound absorber 2 according to 6a where the gap between porous material 19 and level 17 in the edge area additionally with another porous material 21 is provided. Both the circumferential edge 20 as well as the additional porous material 21 allow tuning of the sound absorber 2 on the frequency spectrum to be absorbed.

7 shows a device 1 with a sound transducer 3 , formed by a speaker 7 of the type of a point source and several sound absorbers 2 in the form of slot absorbers. The slot absorbers are arranged in a cassette-like manner to one another, the sound being formed by slots formed between adjacent slot absorbers 20 in the gap between the first plate 16 and level 17 can penetrate. In alternative embodiments, the sound absorber designed as a slot absorber 2 also with other sound transducers 3 such as speakers 7 be combined of the type of a line source and / or a surface source. Furthermore, it is conceivable, the slot absorber with other sound absorbers 2 to combine.

The in the 1 to 7 described facilities 1 can be equipped with additional electronic components. A LAN and / or W-LAN connection allows the integration of the device 1 into a network. An energy supply, formed for example by solar cells, batteries or batteries allows self-sufficient operation of the device 1 , Furthermore, the device 1 have a mixer. A mixer allows program-wise control of the speakers, the mixer setting different sound characteristics of the speakers. To change the sound characteristics, the mixer modifies the control of point, line and area radiators.

It is also possible to have several facilities 1 to combine an array, which includes point sources and area radiator and beyond sensors for detecting the space profile. The sensors should detect extraneous noise and through the device 1 eliminate caused self-signals. This makes it possible to realize at different points of a room a different sound concept from another part of the room.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102009007891 A1 [0003]

Claims (13)

Facility ( 1 ) for actively and / or passively influencing the room acoustics, comprising at least one sound absorber ( 2 ) and at least one sound transducer ( 3 ). Device according to claim 1, characterized in that the device ( 1 ) is plate-shaped. Device according to claim 1 or 2, characterized in that the sound absorber ( 2 ) at least one porous material ( 4 ). Device according to claim 3, characterized in that the porous material ( 4 ) comprises a fiber material. Device according to one of claims 1 to 4, characterized in that the sound absorber ( 2 ) a plate-shaped element ( 5 ). Device according to claim 5, characterized in that the plate-shaped element ( 5 ) is perforated. Device according to one of claims 1 to 6, characterized in that the sound absorber ( 2 ) an absorber with active principle ( 6 ). Device according to one of claims 1 to 7, characterized in that the sound absorber ( 2 ) is formed multi-layered. Device according to one of claims 1 to 8, characterized in that the sound absorber ( 2 ) is designed as a slot absorber. Device according to one of claims 1 to 9, characterized in that the sound transducer ( 3 ) at least one speaker ( 7 ) of the type of a point source, a line source and / or a surface source. Device according to claim 10, characterized in that the sound transducer ( 3 ) at least one speaker ( 7 ) of the type of area source, designed as a bending wave converter comprises. Device according to one of claims 1 to 11, characterized in that a frame ( 8th ) for receiving the sound absorber ( 2 ) and the sound transducer ( 3 ) is provided. Device according to one of claims 1 to 12, characterized in that at least on one side a replaceable cover ( 9 ) is provided.

Images