Patent Publication Number: US-11381919-B2

Title: Speaker box and speaker

Description:
FIELD OF THE INVENTION 
     The invention relates to a speaker box having a speaker housing and a speaker. 
     The invention furthermore relates to a speaker having a speaker chassis that has a flange ring on the output side of the speaker, and having a magnet head on the rear side, opposite the flange ring, of the speaker. 
     Speakers are transducers that convert an electrical input signal into mechanical vibrations that are able to be perceived as sound. They are usually used to generate sound in order to play back music and speech. The typical operating frequency range of speakers is between around 50 Hz and 20 kHz. 
     A speaker box is the name given to the unit consisting of one of more speakers and a housing. Such speaker boxes also optionally contain a crossover network and insulating material in addition to wiring. If it additionally contains an amplifier, the speaker box is referred to as an active box. 
     Speakers, in particular the voice coils, through which current flows, of speakers, constitute a significant source of heat. The heat that is generated is dissipated in part into the air and in part into other speaker elements. 
     In particular in speaker boxes, the heat that arises is often able to be dissipated to the surroundings via the housing only to an insufficient extent, meaning that overheating occurs in the speaker box, in particular in the case of relatively high speaker powers, and speaker components may be damaged. 
     Various concepts have therefore already been developed in order to allow speakers and in particular speaker boxes to be cooled. 
     DE 10 2015 116 660 A1 describes a speaker structure having a frame, a diaphragm, a magnet and a voice coil. The airflows that are generated when playing back sound are guided away from the speaker in a targeted manner by non-return valves, wherein the warm airflows that are channeled away are not able to flow back into the speaker again. 
     GB 2 322 500 A discloses a portable electronic device such as for example a mobile telephone that has an integrated speaker. In order to channel the heat out of the inside of the housing of the electronic device, a small air tube is provided that channels the heat generated at the speaker into the surroundings. In this case, the airflows accompanying the generation of sound at the speaker and vibrational movements of the diaphragm are exploited in order to eject the heated air and draw cooler ambient air into the device. 
     JPH 6-233367 A discloses a speaker box that provides airflow channels on the rear side of the speaker in order to guide the warm airflows generated by the speaker out of the housing into ambient air. 
     Against this background, the object of the invention is to specify an improved speaker box that exhibits simpler and more effective self-cooling. 
     The object is achieved according to the invention by a speaker box having the features of claim  1  and the speakers having the features of claim  17 . Advantageous embodiments are described in the dependent claims. 
     The present speaker box may be designed both as a simple speaker box and as an active box having one or more speakers. In this sense, the terms “a/an” in connection with this application should not be understood to be numbering terms, but rather to be an indefinite article with the meaning “at least one”, such that a speaker box having a speaker may also comprise further, additional speakers. These may also be speaker boxes for domestic use or Hi-Fi requirements, but also powerful speaker boxes having a high sound output for public use, such as concerts for example. These also comprise compact speakers and column or standing speakers. 
     The speaker housing is preferably a bass reflex housing that uses the sound component radiated to the rear by the speaker by using a bass reflex channel as resonator. Other forms of speaker housing are however also included. 
     The speaker usually consists of a diaphragm, the drive unit and connection elements. The diaphragm is driven for example by way of a voice coil. In addition to the coil, the drive includes a magnet in whose field the coil vibrates. A speaker cage, as part of a speaker chassis, connects the magnet to a bead and a spider that guide the diaphragm. 
     The speaker in the present case has a speaker chassis having a flange ring on the output side of the speaker, and a magnet head on the rear side, opposite the flange ring, of the speaker. The speaker is attached to a housing part of the speaker housing by way of its flange ring. 
     There is provision that a section connected to the flange ring and made from metal projects into the speaker housing and forms a channel wall of an air channel. 
     The housing part of the speaker housing may be made from metal and project into the speaker housing by way of a section that forms a channel wall of an air channel. 
     As an alternative or in addition thereto, it is conceivable that the at least one air channel made from metal is formed in one piece (that is to say integrally) with the flange ring of the speaker chassis. In a speaker improved in this way, the flange ring may have at least one air channel formed with the flange ring and having channel walls, wherein the air channel extends from the flange ring in the direction of the rear-side plane, spanned by the magnet head, of the speaker. 
     By virtue of the section made from metal and connected to the speaker chassis and forming an air channel, heat is transferred firstly by convection via the airflows generated by the loudspeaker and exiting via the air channel of the housing and thus dissipating the heat, and secondly also directly via the channel wall and possibly the housing part of the speaker box. The section made from metal is connected to the speaker chassis and has a higher thermal conductivity in comparison with air, meaning that heat dissipation is improved significantly. By virtue of the attachment of the speaker to the housing part made from metal, or the integral design of the channel walls of the air channel with the flange ring, some of the heat that is generated is already reliably dissipated at the point of creation. By virtue of the one-piece formation of the channel wall of the air channel with the housing part or the flange ring, the air channel is formed in a particularly simple manner. The air flowing through the air channel may additionally already lead to improved heat dissipation due to the direct contact with the section made from metal, since the heat is distributed over the entire surface of the section due to the high thermal conductivity of the metal and is thus removed quicker over the entire length of the air channel. 
     The feature whereby the housing part is made from metal does not necessarily mean that the housing part consists entirely of a metal material. In principle, this is understood to mean a predominant two-dimensional or three-dimensional proportion of metal having for example a metal surface area or metal volume of more than 50%. It may also be understood to mean a predominant proportion of metal in terms of the material composition of the housing part when using a material mixture. In one particularly advantageous refinement, the housing part is produced completely from one or more metal materials in order to allow a particularly effective transfer of heat. 
     The housing part may be a housing front of the speaker housing. The housing front may be formed in one piece with the speaker housing. The housing front may however also be a specific component that is connected to the speaker housing in a detachable or non-detachable manner. The housing front is assigned to a front side of the speaker housing, wherein the front side of the speaker housing is assigned to the output side of the speaker. 
     It is however also conceivable for the housing part to be a housing rear side or a housing side wall of the speaker housing. The rear side of the speaker housing is assigned to a side opposite the output side of the speaker. 
     In general, the airflow through the air channel out of the speaker box is ensured not only by the temperature difference between the air inside the speaker box and external ambient air, but also by the vibrations caused by the speaker. The pressure differences in the air that arise locally in this case generate airflows depending on the diaphragm travel, wherein, in the case of a higher power of the speaker that leads to a greater amount of heat at the speaker, stronger airflows also arise. The present speaker box thus experiences dynamic convective self-cooling without additional active cooling components, such as for example blowers, being required. 
     In the case of the speaker box, the flow of heat preferably takes place from the voice coil to the housing part via the speaker chassis of the speaker, and at the same time by way of airflows via the interior of the speaker housing and the air channel of the speaker box. 
     The present structure is furthermore distinguished by improved acoustics in comparison with known airflow-cooled speaker boxes, since the resonance properties of the inside of the housing are not affected by inconveniently arranged air channels, and undesired vibration generators or sound generators, such as for example blowers, are dispensed with. The air channels may additionally at the same time serve as bass reflex ports. Such bass reflex ports, for acoustic reasons, are preferably arranged on the front side of the speaker box that is assigned to the output side of the speaker box and may be equated to the front side of the speaker housing. Bass reflex ports on the front side of the speaker box, in comparison with bass reflex ports on the rear side of the speaker box, in particular in the case of relatively large speaker boxes, have the advantage that there are no propagation time differences when radiating the front sound generated by the speaker and the bass reflex sound, which propagation time differences may lead to a distorted or unclear sound from the speaker box. What are known as built-in boxes additionally exclude the use of air channels that extend at the rear of the speaker, since the built-in boxes are delimited by a wall or ceiling at the rear and it is therefore impossible to exchange air with the surrounding atmosphere. If the air channels serve as bass reflex channels, it is necessary only to provide suitable dimensions of the air channel that are suitable with regard to the frequency and amplitude range of the speaker for bass reflections. 
     As well as this, the housing part according to the present structure may also serve as a support and attachment structure in what are known as floating arrangements of speaker boxes in which the speaker boxes are mounted suspended in the air on struts by way of suitable attachment means, for example. 
     The housing part may be formed from a metal plate. A very simple and nevertheless effective design of the housing part is thereby achieved. The metal plate has a large surface with comparatively little thickness, such that heat is transferred quickly and reliably from one side of the metal plate to the other side. As well as this, the metal plate is easy to produce and easy to process. By way of example, that section of the housing part forming the channel wall may be provided by bending the metal plate. 
     A hollow part may be molded onto the housing part. Such a hollow part may be formed for example as a tube open on both sides with a round or rectangular cross section. The hollow part forms the channel walls of the air channel. In the case of a tubular hollow part, a particularly favorable, in particular low-noise airflow is routed through the air channel as a result of the cylindrical channel shape. The tubes may have structures that increase the surface, such as fins, burls or fractal structures for increasing the cooling surface and thus for improving the cooling effect. The hollow part is in particular formed in one piece with the housing part, but may also be a specific component that is connected to the housing part in a detachable or non-detachable manner. 
     It is advantageous if the channel wall projects beyond the plane of the speaker defined by the bottom of the magnet head of the speaker and into the speaker housing. This embodiment not only supports optical concealment of the speaker and thus the attractive appearance of the speaker box, but also boosts the resonator function of the inside of the housing through the additional wall section. 
     In one particularly expedient embodiment, the length of the channel wall that is formed by that wall section of the housing part projecting into the speaker housing is greater than the height of the speaker as defined from the flange ring to the bottom of the magnet head. A comparatively large distance is thereby provided for the air channel, such that an acceleration and suction effect acts on the airflows present in the inside of the housing, in a manner comparable to a chimney effect, and said airflows are guided reliably and quickly out of the speaker box. 
     An embodiment in which two opposing channel walls protrude from the plane of the housing part next to the flange ring of the speaker and project into the speaker housing is advantageous. This also creates two opposing air channels that are available for channeling out the heated airflows and thus again significantly increase the amount of heat dissipated. On the other hand, the opposing arrangement of the channel walls may also lead to the formation of an air circuit in which cool air flows into the speaker box through one air channel and leaves said speaker box through the other air channel in the form of heated air. Such circulation may for example be supported by way of suitable valves, such as for example non-return valves, in the air channels. 
     It is expedient if an electronics unit for driving the speaker is installed on the channel wall in the interior of the speaker housing. The electronics unit, in addition to the voice coil, may constitute another heat source in speaker boxes that increases the temperature in the speaker box. By virtue of the direct arrangement of the electronics unit on that section of the housing part formed as channel wall, the high thermal conductivity of the housing part made from metal is exploited in order to cool the electronics unit. It is additionally a space-saving arrangement of the electronics unit inside the speaker box, in which it is not necessary to provide any additional holding or carrier unit for the electronics unit. As well as this, the electrical cables of the electronics unit are also able to be laid over a comparatively short distance on the inside of the housing part as far as the speaker, such that it is possible to use short electrical conductors. 
     According to one advantageous embodiment, as an alternative or in addition, an electronics unit for driving the speaker is arranged in the air channel defined by the channel wall. In this embodiment, the airflow emerging from the inside of the housing flows around the electronics unit, thereby efficiently cooling it. The electronics unit is furthermore visible in the air channel from the outside, and may accordingly have a display or interface for communicating with a user, for example a status LED or an optical interface, such as for instance an infrared interface. The resonance chamber of the speaker in the inside of the housing is furthermore not influenced by the electronics unit, since that section of the housing part forming the channel wall may form the reflector wall for the desired sound reflections. 
     An embodiment in which the electronics unit is arranged in the plane of the speaker housing, for example in the plane of the housing part, is also conceivable in principle. By way of example, the electronics unit may be arranged between the output side of the speaker and the housing opening for the air channel. In this embodiment too, it is easier to access the electronics unit from the outside, and a display or interface for communication with a user may be provided on the electronics unit. 
     Whereas speakers or their voice coils do not generate any heat without a signal being applied, the electronics unit undergoes constant heating, including during signal pauses or in a standby state. It is therefore particularly advantageous if the speaker is designed to generate sound signals outside the audible spectrum. The speaker is thereby able to generate an inaudible signal during signal pauses during which no speech or music is being output, which inaudible signal leads to air movements inside the speaker box. The electronics unit is thus able to be cooled continuously by convection. The inaudible signal may for example have a frequency of between 10 and 15 hertz. 
     It is expedient if cooling fins are arranged on the channel wall. These increase the surface of the channel wall and thus improve the transfer of heat to the surroundings, and thereby the desired cooling effect. The cooling fins may in particular already be formed in one piece with the housing part in order to improve the assembly of the speaker box and the transfer of heat between channel wall and cooling fins. 
     An embodiment in which the air channel has a fin structure that increases the surface of the channel walls is advantageous. The cooling effects of the fin structure and of the airflows that are channeled out thereby interact and thus permit a particularly efficient transfer of heat from the inside of the housing to ambient air. 
     According to one advantageous embodiment, the channel wall, formed by a section of the housing part, of the air channel is bent in a meandering shape. The meandering shape contributes to increasing the surface in the longitudinal extent of the channel wall, such that the transfer of heat via the channel wall into the air channel is improved. 
     It is particularly expedient in this case if the meandering bends in the channel wall are formed with a cross section transverse to the airflow direction, seen from the speaker housing towards the surroundings. The cooling effects of the meandering shape and of the airflows that are channeled out thereby interact and thus permit a particularly efficient transfer of heat from the inside of the housing to ambient air. 
     It is expedient if the air channel defined by the channel wall formed by that section of the housing part projecting into the speaker housing has a cross section that changes from the interior towards the exit region. In this case, the interior is assigned to the inside of the speaker housing, whereas the exit region represents the opening of the air channel into the surroundings. By virtue of changes in cross section, it is possible to influence the air speeds at particular points of the air channel. By way of example, the air channel may have a cross section that increases from the interior towards the exit region. Such an air channel increase, for example in the shape of a funnel, towards the surroundings contributes to lowering the pressure of the discharged airflows and thereby reduces additional noise possibly caused by the air movements upon exit from the speaker box. However, it is also equally conceivable, and expedient in certain embodiments, if the air channel has a cross section that decreases from the interior towards the exit region. Such an air channel decrease, for example in the shape of a funnel, towards the surroundings speeds up the airflows in the direction of the surrounding atmosphere, giving rise to a certain suction effect and speeding up or supporting cooling. 
     In one preferred embodiment, the speaker is a bass reflex speaker, a bandpass speaker or a horn speaker. The present invention is able to be applied with a particularly simple structure in the case of these forms of speaker, and displays the desired improved self-cooling effects without any noteworthy influence on the acoustic properties of the speaker. 
     According to one advantageous embodiment, the housing part and the speaker chassis are made from aluminum. Due to the particularly advantageous thermal conductivity of aluminum, the cooling effects that are achieved according to the invention are further increased. As well as this, the overall weight of the speaker box is reduced significantly in comparison with other material compositions, and an attractive appearance of the speaker box is additionally ensured. The reduction in weight is significant in particular for floating arrangements of speaker boxes in which the speaker boxes are mounted suspended in the air on struts by way of suitable attachment means, for example. Due to the fact that the chassis and the housing part consist of aluminum, undesired interactions between the materials of both components are avoided. 
     The advantages according to the invention are also achieved in particular for speaker housings having a plurality of speakers. This relates for example to column speakers and other forms of speaker box in which, in some cases, up to a hundred individual speakers are combined in a housing. The self-cooling effect is increased even further by a plurality of speakers, since a plurality of speakers cause local pressure differences due to their respective diaphragm travel, and the overall air movement inside the speaker box is thus amplified. Furthermore, speakers that themselves generate only little air movement, in particular tweeters, are also jointly cooled by the overall air movement in the speaker box and the common housing part. In this case, a few, preferably fewer than ten and even more preferably fewer than three air channels in the speaker box are sufficient to bring about the required heat dissipation or air circulation. Not every speaker in particular has to have a dedicated airflow channel in order to dissipate heat from the speaker. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in more detail below on the basis of exemplary embodiments along with the attached drawings. In each case schematically: 
         FIG. 1  shows a lateral sectional view of one embodiment of a speaker box having a speaker; 
         FIG. 2  shows a lateral sectional view of a further embodiment of the speaker box having a speaker; 
         FIG. 3  shows a lateral sectional view of a further embodiment of the speaker box having a speaker; 
         FIG. 4  shows a lateral sectional view of a further embodiment of the speaker box having a speaker and an electronics unit; 
         FIG. 5  shows a lateral sectional view of a further embodiment of the speaker box having a speaker and an electronics unit; 
         FIG. 6  shows a front view of a further embodiment of the speaker box having a speaker and an electronics unit; 
         FIG. 7  shows a lateral sectional view of a further embodiment of the speaker box having a speaker; 
         FIG. 8  shows a front view of the embodiment, shown in  FIG. 7 , of the speaker box having a speaker; 
         FIG. 9  shows a lateral sectional view of a further embodiment of the speaker box having a speaker; 
         FIG. 10  shows a front view of the embodiment, shown in  FIG. 9 , of the speaker box having a speaker; 
         FIG. 11  shows a lateral sectional view of a further embodiment of the speaker box having a plurality of speakers; 
         FIG. 12  shows a front view of the embodiment, shown in  FIG. 6 , of the speaker box having a plurality of speakers; 
         FIG. 13  shows a lateral sectional view of a further embodiment of the speaker box having a plurality of speakers; 
         FIG. 14  shows a lateral sectional view of a further embodiment of the speaker box having a plurality of speakers; 
         FIG. 15  shows a plan view of one embodiment of a speaker having integral air channels in the flange ring; 
         FIG. 16  shows a lateral sectional view of the speaker from  FIG. 15 ; 
         FIG. 17  shows a lateral sectional view of a further embodiment of the speaker box having a speaker having integral air channels in the flange ring; 
         FIG. 18  shows a lateral sectional view of the speaker, shown in  FIG. 17 , having integral air channels in the flange ring; 
         FIG. 19  shows a perspective view of the speaker from  FIG. 18 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a sectional view of the speaker box  1  according to the invention having a speaker housing  2  and a speaker  3 . Further components usually present in a speaker box  1 , such as for example electrical cables, drive units or mechanical attachment means, are not illustrated for the sake of clarity. The speaker  3  has a speaker chassis  4  in the form of a cage that supports the speaker diaphragm. The speaker  3  has a flange ring  5  for the attachment of the speaker  3  on an output side  6  of the speaker  3 . The speaker  3  has a magnet head  8  on a rear side  7 , opposite the flange ring  5 , of the speaker  3 . On the front side of the speaker housing  2  that is assigned to the output side  6  of the speaker  3 , there is provided a housing part  9  made from metal that is connected to the speaker housing  2  and is attached to the speaker  3  via the flange ring  5 . The speaker housing  2  in the present case is designed with a U-shape cross section and, together with the housing part  9 , forms a substantially cuboidal housing. Other housing shapes, for example rounded ones, are however also conceivable for the speaker housing  2 . 
     The housing part  9  is formed as a metal plate in the drawings. The housing part  9  is bent into the interior  13  of the speaker housing  2  in a region to the side of the speaker  3 . That section of the housing part  9  projecting into the interior  13  forms a channel wall  10  of an air channel  11 . The one-piece form of the channel wall  10  with the housing part  9  allows an air channel  11  that is particularly easy to produce and an optimum transfer of heat not only through the airflows  19  escaping from the speaker housing  2  through the air channel  11 , but also via the adjoining housing part  9 . In principle, however, a formation of a housing subsection that is not in one piece is also possible, in which for example that part of the housing part  9  forming the channel wall  10  is produced specially and is screwed to the housing part  9 , for example using brackets. The air channel  11  forms an opening in the speaker housing  2  and allows air to be exchanged between the interior  13  of the speaker housing  2  and the surrounding atmosphere  16  surrounding the speaker housing  2 . 
     During operation of the speaker  3 , the speaker  3  heats up, in particular in the region of its voice coil, not illustrated. The heat is able to leave the speaker housing  2  firstly via the speaker  3  itself and the adjoining housing part  9  and secondly by convection through heat dissipation to the air surrounding the speaker  3 . The diaphragm movement of the speaker  3  caused by applied signals generates air movements that promote the formation of airflows  19  that leave the speaker housing  2  via the air channel  11 . As a result, the cooling of the interior  13  of the speaker housing  2  and thus also of the speaker  3  is improved. Due to the relatively strong air movements in the case of increased signal amplitude, which also leads to increased heating of the speaker  3 , a stronger airflow  19  is also generated, and the cooling effect is increased. Dynamic self-cooling of the speaker box  1  is thus provided. The airflow direction of the airflows  19  normally runs in the air channel  11  from the interior  13  in the direction of the surrounding atmosphere  16 , as illustrated by the arrow. Different airflow directions may however occur in the case of an air circulation that possibly arises in the case of at least two air channels  11 , in which cool air from the surrounding atmosphere  16  enters the speaker box  1  and heated air from the interior  13  leaves via another air channel  11 . 
     The housing part  9  made from metal has a high thermal conductivity. This therefore already leads to improved heat dissipation at the speaker  3  itself, which is attached to the housing part  9  via the flange ring  5 . By virtue of forming the channel wall  10  for the air channel  11 , faster cooling of the airflow  19  along the air channel  11  also takes place, since part of the heat is output from the airflow  19  to the housing part  9  and leaves the speaker housing  2  thereby. 
     In the exemplary embodiment, the housing part  9  is an aluminum plate that is able to be processed easily due to the material properties of aluminum, for example is able to be bent sectionally into the channel wall  10 , has a low weight and is distinguished in particular by a particularly high thermal conductivity. 
     The interior  13  of the speaker box  1  is not only a reception space for the components of the speaker box  1 , but also performs important acoustic functions for the sound quality of the speaker  3 . The interior  13  in principle forms a resonance chamber for amplifying the sound waves output by the speaker  3 . The interior  13  may furthermore form a bass reflex chamber that reflects sound waves of the speaker  3  radiated toward the rear in a targeted manner and thereby advantageously supplements the sound pattern of the speaker  3 . The present structure allows the speaker box  1  to be cooled via an air channel  11  without the interior  13  and thus the resonance or bass reflex chamber being disadvantageously influenced. This is achieved by way of the channel wall  10  projecting from the housing part  9 , which channel wall  10  forms a substitute reflection wall and allows the interior  13  to be screened in part from the air channel  11 . 
       FIG. 1  shows an embodiment in which the channel wall  10  projects beyond the plane  12  of the speaker  3  defined by the bottom of the magnet head  8  of the speaker  3  and into the speaker housing  2 . As a result, not only are the abovementioned advantages of improved acoustics achieved through the formation of a substitute reflection wall, but sufficient optical concealment of the inside of the housing is also achieved. This prevents an observer from looking directly through the air channel  11  at the speaker  3  and the associated electronics. 
     The length L of the channel wall  10  that is formed by that section of the housing part  9  projecting into the speaker housing  2  is additionally greater than the height H of the speaker  3  as defined from the flange ring  5  to the bottom of the magnet head  8 . As a result, the air channel  11 , as may be seen in the figure, is comparatively long or takes up almost the entire length of the speaker housing  2 . The airflow  19  is thus sufficiently directed and sped up within the air channel  11 , such that the transfer of heat to the surrounding atmosphere  16  is improved. 
     Embodiments of the air channel  11  that have a length shorter than the height H are in principle however also conceivable. 
     The embodiment shown in  FIG. 2  differs from the embodiment illustrated in  FIG. 1  essentially in that the housing part  9  is not arranged between the flange ring  5  and the speaker chassis  4 , as shown in  FIG. 1 , but the flange ring  5  in  FIG. 2  directly adjoins the speaker chassis  4  and is connected at the end face to the housing part  9 . In the region of the speaker opening on the output side  6  of the speaker  3 , the housing part  9  has a recess in order not to impair the operation of the speaker  3 . The embodiment shown in  FIG. 2  allows a more attractive appearance of the speaker box  1 , in the present case of the front side of the speaker box  1 , since the flange ring does not protrude out of the plane of the housing part  9 . Instead of this, the speaker  3 , including the flange ring  5 , is recessed into the speaker housing  2 . The flange ring  5  is thus attached to the housing part  9  on an inner side, facing the interior  13 , of said housing part. 
     The embodiment shown in  FIG. 3  differs from the embodiment shown in  FIG. 1  in that the housing part  9  is bent into the interior  13  at two opposing ends and thus forms channel walls  10  for two opposing air channels  11 . The amount of heated air that is able to leave the speaker housing  2  per unit of time is thereby increased significantly. As well as this, it is conceivable to form an air circulation in which cool air enters through one of the two air channels  11  and heated air exits through the other air channel  11 . 
       FIG. 4  essentially shows a speaker box  1  having the features described with regard to  FIG. 1 . In this embodiment, however, an electronics unit  14  for driving the speaker  3  is additionally arranged on the housing part  9 , specifically on the channel wall  10  in the interior  13  of the speaker housing  2 . As shown in the drawing, this may be arranged on a side, facing away from the air channel  11 , of the channel wall  10 . An arrangement of the electronics unit  14  on a side, facing the air channel  11 , of the housing part  9  is in principle however also conceivable. The heat generated by the electronics unit  14  is not only dissipated by convection through air movements and the airflows  19 , but also in particular via the directly adjoining housing part  9  that has a high thermal conductivity. If the housing part  9  or the channel wall  10  serves as support for the electronics unit  14 , it is additionally not necessary to arrange any other carrier structures for the electronics unit  14  that could negatively influence the acoustic properties of the interior  13  in the interior  13 . 
     The acoustics of the speaker box  1  are improved further when the electronics unit  14  is arranged in the air channel  11 , as in the embodiment shown according to  FIG. 5 . The resonance or bass reflex chamber is thereby kept free on the rear side  7  of the speaker  3 . By virtue of the airflows  19  channeled in the air channel  11 , the electronics unit  14  is cooled sufficiently by convection and does not require any additional active cooling units such as blowers for example. 
       FIG. 6  shows one embodiment in a front view of the speaker box  1 , in which the electronics unit  14  is placed on the front side between the air channel  11  and the speaker  3 , adjoining the housing part  9 . This arrangement achieves a particularly high cooling efficiency for the electronics unit  14 , since it firstly adjoins the housing part  9  made from metal and having a high thermal conductivity, secondly is cooled by the airflows  19  escaping from the air channel  11  and, as well as this, is in direct contact with the surrounding atmosphere  16  at the front side of the speaker housing  2 . A display or interface for optical communication with a user may furthermore be provided on the electronics unit  14 , since the electronics unit  14  in this embodiment is not concealed by housing parts and is also optically visible from different angles. 
     In  FIG. 6 , the housing part  9  is arranged on a front side, assigned to the output side  6  of the speaker  3 , of the speaker housing  2 . It is possible to see that section of the housing part  9  that is arranged in this case at the front and also the flange ring  5 , attached to the housing part  9 , on the output side  6  of the speaker  3 . The air channel  11  is arranged to the side of the housing part  9  or of the speaker  3  and forms a visible opening within the speaker housing  2 . According to one advantageous refinement, the air channel  11  has a fin structure  15  that increases the surface of the channel wall  10  in order to further increase the cooling effect. 
       FIGS. 7 and 8  show a further embodiment of the speaker box  1  in which a hollow part  20  is molded onto the housing part  9 .  FIG. 7  shows a sectional side view, whereas  FIG. 8  shows a front view of the front side of the speaker box  1 . The hollow part  20  in  FIGS. 7 and 8  is formed as a tube open on both sides with a round cross section and projects from the housing part  9  into the inside of the speaker housing  2 . In this case, the hollow part  20  forms the channel walls  10  of the air channel  11 , such that a tubular air channel  11  is provided in the present case. A particularly favorable, in particular low-noise airflow  19  is routed through the air channel  11  as a result of the cylindrical channel shape. In the same way as  FIG. 2 , the flange ring  5  is located in a plane that is offset in the direction of the interior  13  with respect to the plane of the housing part  9  in order to recess the speaker  3  into the speaker housing  2 . The flange ring  5  is thus attached to the housing part  9  on an inner side, facing the interior  13 , of said housing part. 
       FIGS. 9 and 10  show a further embodiment of the speaker box  1  in which a hollow part  20  is molded onto the housing part  9 .  FIG. 9  shows a sectional side view, whereas  FIG. 10  shows a front view of the front side of the speaker box  1 . The hollow part  20  in  FIGS. 9 and 10  is formed as a tube with fins that is open on both sides with a rectangular cross section and projects from the housing part  9  into the inside of the speaker housing  2 . In this case, the hollow part  20  forms the channel walls  10  of the air channel  11 , such that a tubular air channel  11  is provided in the present case. A particularly high cooling effect through the cooling channel  11  is achieved by the fin structure  15  on the channel walls  10 . 
       FIGS. 11 to 14  show embodiments of the speaker box  1  having a plurality of speakers  3 . 
       FIG. 11  shows, by way of example, one embodiment of an elongate speaker box  1  having two rows of in each case three speakers  3  arranged next to one another. The speakers  3  of a respective row are connected to one another by a common housing part  9 , wherein the housing part  9  has sections protruding into the interior  13  at two opposing ends and that each form an air channel  11  adjoining a channel wall  10 . As illustrated, this results in a total of three air channels  11  that serve to channel heat out of the interior  13  of the speaker box  1  via airflows  19 . In addition, heat generated by the speakers  3  is output directly to the housing parts  9 , thereby forming overall a cooling concept that takes effect in several ways. 
       FIG. 12  illustrates the arrangement from  FIG. 11  again in a front view that shows the two rows of speakers with the adjoining air channels  11  from the front perspective. 
       FIG. 13  shows an embodiment with five speakers  3  arranged in a row in a sectional view. The row of speakers consists of three woofers  17  and two tweeters  18 . All of the speakers  3  are connected to one another by a common housing part  9 , wherein the housing part  9  has sections protruding into the interior  13  at two opposing ends and that each form an air channel  11  adjoining a channel wall  10 . As illustrated, this results in a total of two air channels  11  that serve to channel heat out of the interior  13  of the speaker box  1  via airflows  19 . In addition, heat generated by the speakers  3  is output directly to the housing part  9 , thereby forming overall a cooling concept that takes effect in several ways. 
     The tweeters  18 , just like the woofers  17 , may be connected to the housing part  9  via flange rings. Other attachment options, such as for example clamping or adhesively bonding into an opening of the housing part  9 , however also come into consideration for allowing the tweeters  18  to terminate flush with the housing part  9 . When signals are applied, the tweeters  18  generate only very little diaphragm travel, and therefore also only little to no measurable air movement. In the present arrangement, however, they are cooled jointly by the airflows  19  generated by the woofers  17  in addition to the transfer of heat via the housing part  9 , such that the cooling effect acts on all of the speakers  3  contained in the speaker box  1 . 
       FIG. 14  shows a speaker box  1  having three speakers  3  which, in contract to the arrangements shown in  FIGS. 11 to 13 , are not arranged in a plane, but rather placed at an angle to one another. The speaker box  1  has two woofers  17  and a tweeter  18  between them. The speakers  3  are connected to one another via a common housing part  9 . For this purpose, the housing part  9  is bent multiple times in order to allow the speakers  3  to be set at different angles to one another and in order to form two opposing channel walls  10  for adjoining cooling channels  11 . In this embodiment too, the tweeter  18  is cooled by way of a transfer of heat via the housing part  9  and by convection through the airflows  19  generated by the woofers  17 . The channel walls  10  furthermore protrude into the interior  13  of the speaker housing  2 , thereby forming a cross section of the air channels  11  that narrows from the interior  13  towards the exit region into the surrounding atmosphere  16 . This tapering of the air channels  11  speeds up the airflows  19  in the direction of the surrounding atmosphere  16 , giving rise to a certain suction effect and supporting the cooling. 
       FIG. 15  shows a plan view of a bass reflex speaker  3  that has air channels arranged in a manner distributed over the circumference on its flange ring  5 . These are arranged for example at the four corners of the flange ring  5 , which had a square outer profile, and is formed integrally with the flange ring  5  made from metal. The air channels  11  are defined by channel walls  10  that form a circular segment-shaped or crescent-shaped cross section. Other cross-sectional surfaces are also however conceivable. The air channels  11  emerge at the output side of the speaker  3 , that is to say the sound emission side, as visible in  FIG. 15 . 
       FIG. 16  shows a lateral sectional view of the speaker  3  from  FIG. 15 . It is able to be seen that the air channels  11  extend from the plane of the flange ring  5  in the direction of the rear magnet head  8  or the plane spanned by the magnet head  8 . By way of example, the channel walls  10  of the air channels  11  run approximately parallel along the speaker chassis  4 , such that the air channels  11  run obliquely from the flange ring  5  to the magnet head  8 . They may end before the magnet head  8 , as illustrated, or be continued further towards the rear end of the magnet head  8  or beyond. 
       FIG. 17  shows a lateral sectional view of a speaker housing  2  with a speaker  3  inserted at the front. In this case too, heat is dissipated not though the front housing part of the speaker housing  2 , but rather through the air channels  11 , formed integrally with the flange ring  5 , having the associated channel walls  10  made from metal. In this exemplary embodiment, these are continued almost to the end of the magnet head  8  and angled at the magnet head  8 , such that the air channels  11  first of all run diagonally from the output side and parallel to one another in the region of the magnet head  8 . 
       FIG. 18  shows a lateral sectional view of a DAC speaker  3 , in which the air channels  11  already end before the magnet head  8 . The length, the cross section and the direction of extent, with any changes of direction, may be selected depending on the desired bass reflex properties. 
       FIG. 19  shows a perspective view of the DAC speaker  3  from  FIG. 18 . It is able to be seen that the channel walls  10  of the air channels  11  emerge at the four corners of the flange ring  5  and are directed diagonally inwards towards the plane spanned by the magnet head  8 . The air channels  11  then meet at a virtual common point of intersection that lies behind the magnet head  8  as seen from the flange ring  5  towards the magnet head  8 . The channel walls  10  may in this case cling to the speaker chassis  4  or be formed integrally with those sections of the speaker chassis  4  extending from the flange ring  5  towards the magnet head  8 . 
     LIST OF REFERENCE SIGNS 
       1  Speaker box 
       2  Speaker housing 
       3  Speaker 
       4  Speaker chassis 
       5  Flange ring 
       6  Output side (speaker) 
       7  Rear side (speaker) 
       8  Magnet head 
       9  Housing part 
       10  Channel wall 
       11  Air channel 
       12  Plane (bottom of magnet head) 
       13  Interior 
       14  Electronics unit 
       15  Fin structure 
       16  Surrounding atmosphere 
       17  Woofer 
       18  Tweeter 
       19  Airflow 
       20  Hollow part 
     H Height (speaker) 
     L Length (channel wall)