EP1586219B1 - Loudspeaker - Google Patents

Abstract

The invention relates to a loudspeaker comprising at least one magnet ( 5 ), a membrane ( 2 ) with an outer edge ( 32 ) defining an outer edge plane ( 30 ) of the membrane, a bead ( 3 ) surrounding the membrane ( 2 ), a moving coil ( 9 ) which is fixed to the first membrane ( 2 ), and a magnet system ( 4 ) comprising at least one magnet ( 9 ). The loudspeaker also has a supporting structure ( 1 ) for receiving the magnet system ( 4 ) and the membrane, the membrane being connected to the supporting structure by means of the bead, and the supporting structure has a front side which is oriented towards the membrane and a rear side which is oriented in the opposite direction. The membrane ( 2 ) is at least partially convex towards the front, in the predominant acoustic direction ( 33 ), and the region ( 28 ) of the membrane ( 2 ), to which the moving coil is fixed, is arranged in front of the outer edge plane ( 30 ) of the membrane. The diameter (D) of the membrane ( 2 ) is larger than the diameter of the moving coil (d) which moves the membrane ( 2 ).

Description

The invention relates to a loudspeaker, which is designed as an electrodynamic transducer, with at least a first magnet, a first membrane with a membrane outer edge, which spans a membrane outer edge plane, a first bead encircling the first membrane for flexible storage of the first membrane, wherein the bead of a Another material consists of the first membrane, a first voice coil indirectly or directly attached to the first diaphragm, and a magnet system having at least a first magnet, and a support structure (basket) for receiving the magnet system and the first diaphragm, the first diaphragm via the first bead is connected to the support structure, and the support structure has a membrane-oriented front and an oppositely oriented back.

Similar speakers are well known. By way of example, the German patent application DE 36 03 537 A1 directed. This document shows a full-range speaker with a membrane, which is driven by a voice coil and a permanent magnet, wherein the membrane has at its membrane outer edge a circumferential bead through which the membrane is flexibly supported. The bead is attached to a support structure, also called a basket, attached, wherein the support structure is also used to hold the entire centrally arranged magnet system. The membrane is in this case thus formed opposite to the sound preferred direction of the speaker and forms a kind of funnel, at the top of the magnet system is arranged so that a total of the basket and the magnet system located outside the basket a large installation depth is necessary.

Due to the today required problem-free mounting options of speakers, such as in the car or Aerospace industry, but it is required that speakers are as flat as possible and low-order, or even on flat surfaces, for example, on motor vehicle doors or -Verkleidungen without special preparation, can be attached. Today's doors of a motor vehicle are usually kept very flat and have a variety of wiring harnesses and electrical systems that largely fill the existing space and cavity. In addition, the guidance and mechanics of the windows and the closing mechanism of the door with the necessary struts for side impact protection often require large space, so that the installation of a loudspeaker desired there often encounters great difficulties.

Alternatively, it is possible to attach the speakers in other places, for example in the footwell or in the dashboard. However, there is also basically a space problem, and in addition the acoustic quality suffers greatly due to unfavorable positioning.

On the market, there are various flat speaker systems according to other design principles, but such systems often have too low efficiency and too low bandwidth. Furthermore, there is also a high mechanical susceptibility, no temperature resistance or a temperature-dependent acoustic behavior.

It will also continue on to the patent DE 36 38 727 C2 In this embodiment, the acoustic quality is impaired by the fact that in the area of the preferred sound propagation the magnet system is mounted in front of the diaphragm and therefore the undisturbed propagation of sound is hindered. In addition, a stable attachment of the magnet system is difficult because of a compromise between stability of the carrier for the magnet system and free sound propagation must be received.

It is an object of the invention to provide a speaker that works on the one hand after the proven simple system of electrodynamic sound conversion with permanent magnet and voice coil, but meets the modern requirements for flat design and high acoustic quality.

The object is solved by the features of claims 1. Advantageous embodiments of the invention are set forth in the dependent claims and the figures including description.

The inventor has recognized that a solution to the above-mentioned problem can be achieved by providing the loudspeaker with a diaphragm that is curved in the direction of sound propagation, driven by a voice coil and a magnet, the magnet system at least partially engaging that of the membrane Volume dips, creating a very flat design of the support structure or basket is possible. In this case, a magnet system is used with at least one permanent magnet which forms an annular gap, optionally by means of the aid of a yoke or another magnet, wherein the voice coil can dip into this annular gap. The magnet system can be brought very close to the membrane, so that the membrane outer edge surface formed by the outer edge of the membrane is cut by the magnet system. On the one hand, this produces an extremely flat design of the magnet. On the other hand, a very good and broadband acoustic characteristics of the speaker system is obtained.

• einem ersten Magneten,
• einer ersten Membran mit einem Membranaußenrand, der eine Membranaußenrandebene aufspannt,
• einer die erste Membran umlaufenden ersten Sicke zur flexiblen Lagerung der ersten Membran, wobei die Sicke aus einem anderen Material besteht als die erste Membran,
  • einer ersten Schwingspule, die mittelbar oder unmittelbar an der ersten Membran befestigt ist, und
  • einem Magnetsystem mit mindestens einem ersten Magneten (Permanentmagneten), weiterhin
• einer Tragkonstruktion (Korb) zur Aufnahme des Magnetsystems und der ersten Membran, wobei die erste Membran über die erste Sicke mit der Tragkonstruktion verbunden ist, und die Tragkonstruktion eine zur Membran orientierte Vorderseite (Schallausbreitungsvorzugsrichtung) und eine entgegengesetzt orientierte Rückseite aufweist,

dahingehend zu verbessern, dass

• die erste Membran zumindest teilweise nach oben erhaben ausgebildet ist und der Bereich der ersten Membran, an der die erste Schwingspule befestigt ist, vor der Membranaußenrandebene angeordnet ist, wobei
• die erste Membran einen Durchmesser aufweist, der größer ist als der Durchmesser der ersten Schwingspule, die diese Membran bewegt,
• der erste Ringspalt in Richtung Membran einen verengten parallelen Bereich aufweist, und
• das gesamte Magnetsystem vor der Tragkonstruktion (=Korb) angeordnet ist.

On the basis of these underlying considerations, the inventor proposes that the loudspeakers known per se be composed at least of:

• a first magnet,
• a first membrane having a membrane outer edge which spans a membrane outer edge plane,
• a first bead encircling the first membrane for flexibly supporting the first membrane, wherein the bead is made of a different material than the first membrane,
  • a first voice coil directly or indirectly attached to the first diaphragm, and
  • a magnet system with at least one first magnet (permanent magnet), furthermore
• a support structure (basket) for receiving the magnet system and the first membrane, the first membrane being connected to the support structure via the first bead, and the support structure having a membrane-oriented front side (sound propagation preferential direction) and an oppositely oriented back side,

to improve that

• the first membrane is at least partially raised to the top and the region of the first membrane, to which the first voice coil is fastened, is arranged in front of the membrane outer edge plane, wherein
• the first diaphragm has a diameter greater than the diameter of the first voice coil that moves this diaphragm,
• the first annular gap in the direction of the membrane has a narrowed parallel region, and
• the entire magnet system in front of the supporting structure (= basket) is arranged.

This construction makes possible an extremely flat and also compact design of the loudspeaker system, so that it is particularly suitable for mounting in vehicles. However, other applications requiring a flat design of the speaker system are also possible.

In a particularly preferred embodiment of the loudspeaker, the inventor proposes that the magnet system should be the membrane outside edge plane at least intersects or optionally even above the membrane outer edge plane is arranged. This means that the magnet system is at least partially within the volume defined by the membrane. The magnet system may preferably have a first annular gap in which the first voice coil can dip. As a result, a particularly good leadership is achieved. If the voice coil designed sufficiently large, then the natural vibration behavior of the membrane can thereby stabilize much better and the membrane can be made very flat and thin. This increases the efficiency of the system and the stroke of the membrane can be reduced.

In a further variant of the loudspeaker, it may additionally be provided to arrange at least one further membrane within the first membrane, so that a multi-way system can thereby be realized. In this case, the magnet system can also have at least one further annular gap, in each of which a further voice coil can dive for another membrane.

The first membrane may also have an inner further bead, which is connected to the magnet system, so that in this way an additional centering of the membrane is achieved.

The membrane can also be made in several parts. This has the advantage that in this way the central area can be designed with other lighter materials, so that a better dynamic at high frequencies is achieved.

As a result, and by a corresponding configuration of the magnet system, the speaker can be configured not only as a one-way system, but also as a two-, three- or Mehrwegesystem.

A further advantageous embodiment of the loudspeaker may consist in that the magnet system has at least one ring magnet and at least one pole plate, which form the at least one air gap.

In addition, the magnet system can be formed of a plurality of ring magnets, a lower pole plate and each magnet of an upper pole plate, wherein the air gaps are arranged between the pole plates. This embodiment of the magnet system makes a very effective multipath system possible, the inner annular gap being provided for driving a tweeter.

Although in the loudspeaker according to the invention can be dispensed with special centering, so this is still advantageous in special cases, especially if the size requires additional centering. The magnets of the magnet system can be enclosed in a ring shape by the respective associated voice coil.

Furthermore, it may be advantageous if the pole plates of the magnet system are made of magnetic material, as a result, a high flux density can be generated with well-defined field lines in the region of the air gap.

In a particular embodiment, the magnet system can be configured such that a ring magnet is located within a larger and at the same time outside a smaller voice coil. It is particularly advantageous here to design the rear pole plate as a magnetic yoke, so that a narrow air gap, in each case inside and outside of the ring magnet, is formed by the front and rear pole plate.

The materials of the permanent magnet can be very different variants. However, neodymium iron or neodymium iron boron or rare earth cobalt (eg SmCo ₅ , Sm ₂ Co ₁₇ ) or other hard ferrites are particularly advantageous.

With regard to the construction of the loudspeaker, the inventor proposes that at least one magnet is provided with at least one screw and / or adhesive and / or clamping elements on the membrane basket is attached, and combinations of these mounting options are proposed.

With regard to the design of the membrane, the inventor proposes that it may consist for example of a foamed material, which is preferably provided with a one- or two-sided barrier layer. For example, it may be an aluminum and magnesium foam, polystyrene - rigid foam, PVC, polyolefin material, polyurethane, polyester, Styrofoam or sandwich panels with honeycomb construction.

Another variant of the configuration of the membrane or a part of the membrane may consist in that it consists of a shaped film or sandwich products, preferably of polyester, polyimide, Bextrenen, polycarbonate, aluminum, magnesium, polypropylene, paper, fibrous, Kevlar, carbon fiber, Glass fiber, Nomex or mixed products of the aforementioned materials is produced.

In addition, on at least one membrane, preferably the single membrane, an inversely shaped Dust Cap, also called dome, dome or Staubschutzkalotte be arranged.

The at least one intended bead can for example be made of rubber or coated foam material, fiber materials or paper.

In the central region of a membrane, the above-mentioned "Dust Cap" can be attached, with a centering, for example made of spring steel or fiber materials, can be located behind it.

With respect to the supporting structure or the basket, the inventor proposes that this be made, for example, of plastics or metal materials, wherein it is advantageous to provide the basket with openings to a physical Coupling to the back air volume to effect any existing trim or a housing.

For example, the back of the basket can be designed as a level, so that behind the speaker no openings for installation are necessary. However, it is also possible to form the back of the basket as a flat truncated cone, preferably with a slope of not more than 20 °, preferably not more than 10 °, with respect to the plane.

To protect the membrane may further be provided in front of the membrane, a protective grid, as is common practice in the art.

With regard to the size ratios of the loudspeaker in a preferred embodiment, the inventor proposes that the ratio B / T of greatest width B of the loudspeaker's largest diaphragm to maximum loudness of the loudspeaker T with respect to the components diaphragm and magnet system is greater than 3/1, preferably greater than 5/1, preferably greater than 10/1.

Fig. 1:

Ein-Wege-Lautsprecher mit einem Permanentmagne- ten;

Fig. 2:

Ein-Wege-Lautsprecher mit einem Permanentmagneten und Dust Cap;

Fig. 3:

Varianten der Membranformgebung im Ein-Wege- Lautsprecher mit einem Permanentmagneten;

Fig. 4:

Ein-Wege-Lautsprecher mit einem Permanentmagneten und Zentrierung als Metallfeder;

Fig. 5:

Ein-Wege-Lautsprecher mit einem Permanentmagneten und Zentrierung aus Gewebe;

Fig. 6:

Zwei-Wege-Lautsprecher mit einem Permanentmagne- ten und zentralem Hochtöner;

Fig. 7:

Ein-Wege-Lautsprecher mit zwei Permanentmagneten;

Fig. 8:

Ein-Wege-Lautsprecher mit zwei Permanentmagneten und Dust Cap;

Fig. 9:

Zwei-Wege-Lautsprecher mit drei Permanentmagneten und zentralem Hochtöner;

Fig. 10:

Zwei-Wege-Lautsprecher mit drei Permanentmagneten und leicht konischem Korb;

Fig. 11:

Vergrößertes Magnetsystem aus Figur 5;

Fig. 12:

Ansicht von hinten auf den Korb;

Fig. 13:

Ansicht von vorne auf Membran und zentralen Hoch- töner mit randseitigen Schraubenlöchern;

Fig. 14:

Ansicht von vorne auf Membran und zentralen Hoch- töner ohne randseitige Schraubenlöcher.

In the following the invention will be described with reference to the preferred embodiments with reference to the figures. They show in detail:

Fig. 1:

One-way loudspeaker with a permanent magnet;

Fig. 2:

One-way speaker with a permanent magnet and dust cap;

3:

Variants of the membrane shaping in the one-way loudspeaker with a permanent magnet;

4:

One-way speaker with a permanent magnet and centering as a metal spring;

Fig. 5:

One-way loudspeaker with a permanent magnet and centering of tissue;

Fig. 6:

Two-way loudspeakers with a permanent magnet and central tweeter;

Fig. 7:

One-way speaker with two permanent magnets;

Fig. 8:

One-way speaker with two permanent magnets and dust cap;

Fig. 9:

Two-way loudspeakers with three permanent magnets and central tweeter;

Fig. 10:

Two-way speaker with three permanent magnets and slightly conical basket;

Fig. 11:

Magnified magnet system off FIG. 5 ;

Fig. 12:

View from the back on the basket;

Fig. 13:

Front view of diaphragm and central tweeter with peripheral screw holes;

Fig. 14:

Front view of diaphragm and central tweeter with no screw holes on the outside.

The FIG. 1 shows a section through a simple broadband and inventively designed speaker with a single membrane 2, which is spanned on a flat running basket 1, which runs flat on the back. The membrane 2 is connected at its outer edge 32 by a bead 3 with the basket 1 and clamped by its outer edge 32 has an outer edge plane 30. On the front of the basket 1, a magnet system 4 is fixed, which consists of a ring-shaped permanent magnet 5, the front has a likewise annularly shaped pole plate 6 and on the back of an expiring to a yoke 13 rear pole plate 7. Between the yoke 13 of the rear pole plate 7 and the front pole plate 6, an air gap 8, in which the voice coil 9, which is connected to the membrane 2 in the region 28, can dip. Thus, in known manner by electrical impulses the membrane 2 excited to movements and sound are generated.

The Schallausbreitungsvorzugsrichtung, which also defines the front of the speaker is indicated by the arrow 33. Furthermore, the outer diameter D is the right Diaphragm 2 and the smaller diameter d of the associated voice coil 9 indicated on the right side. According to the invention, in this embodiment, the magnet system 4 due to the curvature of the membrane 2 and the close attachment of the voice coil 9 is moved strongly forward, so that the front pole plate 6 and the effective region of the yoke 13, which form the air gap 8 in front of the membrane outer edge plane 30 ; the permanent magnet 5 is cut by the membrane outer edge plane 30. As a result, an extremely flat design of the speaker is possible.

It should also be noted that, in particular with loudspeakers with larger diameters, the permanent magnet 5 or the entire magnet system 4 can even lie completely in front of the membrane outer edge plane.

The FIG. 2 shows a similar embodiment of a broadband one-way speaker, but in this version, the membrane 2 has been replaced in a central region by a lighter concave material 12. The replacement of the central portion of the membrane 2 by lighter material has the advantage that the inertial mass of the membrane is thereby reduced and the useful frequency range of the loudspeaker can be extended to higher frequencies.

The FIG. 3 shows a further variant of a one-way system, similar to the execution of FIG. 1 , In this case, the FIG. 3 have been divided into an upper and a lower variant of a membrane design. The upper variant of the membrane design shows a flat conical membrane 2, which leads from the outer bead 3 to the region of the voice coil and then has a slightly concave shape in the central region. In addition, the membrane has a centering 20 which is formed here in the form of a metal spring. The lower parts of the FIG. 3 shows another exemplary form of the membrane 2, the edge initially largely flat, then an increase experiences a maximum in the field of the voice coil and is concave again in the central region.

The FIG. 4 again shows the same membrane contours as the FIG. 3 However, the edge arranged beads 3 are provided with multiple wavy lines, while in the FIG. 3 only one survey for the bead is provided. The centering 20 of the membrane 2, which in the FIG. 4 is shown here, for example, consists of a fabric material.

Another embodiment of the speaker according to the invention is in the FIG. 5 shown. This shows a section through a two-way loudspeaker according to the invention, in which case the outer membrane 2 of the embodiment FIG. 2 corresponds, however, an additional tweeter has been integrated into the magnet system 4 in the central area. For this purpose, the magnet system from the Figures 1 or 2 modified in that the rear pole plate has a second, centrally located yoke 14 which forms a second air gap 15 in connection with the front pole plate 6. In this air gap, a second voice coil 17 can dip, which drives a thin tweeter membrane 18. The high-tone membrane 18 is fastened here via a bead 19 on the front pole plate 6 of the magnet system 4.

The FIG. 6 shows again a modification of the two-way loudspeaker according to the invention from the FIG. 5 , In this case, the outer membrane 2 in its two illustrated variants of the membrane forms of the FIG. 3 equivalent. However, due to the tweeter now centrally arranged in the magnet system, an additional flexible attachment of the outer membrane 2 is made by a further inner bead 21, wherein the inner part of this bead 21 is fixed to the front pole plate 6 of the magnet system 4. The design of the magnet system again corresponds to that already in FIG. 5 shown execution.

In the FIG. 7 another variant of a one-way speaker according to the invention is shown. Basically, the shape of the speaker's design matches FIG. 1 , where the essential difference is in the magnet system. Here, instead of a single permanent magnet 5, both an inner permanent magnet 5 and a further outer annular permanent magnet 22 are provided, both permanent magnets having front pole plates 6 and 23, between which the single air gap 8 is formed. In this construction, it is now possible to dispense with the rear pole plate, as shown in the previously shown magnetic systems. The advantage of such an embodiment is essentially that this design without reflux makes it possible to significantly reduce the overall height of the magnet system or on the other hand to achieve a very large stroke at the same height.

In the FIG. 8 is another sectional view of a one-way speaker shown having the same magnet system with two ring magnets as FIG. 7 , wherein the formation of the membrane is in turn designed so that in the central region a so-called "dust cap" is present, which reduces the inertial mass of the oscillating membrane.

According to the design of the magnet system from the FIGS. 7 and 8 , show the FIG. 9 a development with additionally arranged inside tweeters, for the voice coil of the tweeter again a third permanent magnet 25 is shown with front pole plate 26 and between the centrally located front pole plate 26 and the middle pole plate 23, the air gap for the voice coil 17 of the tweeter 24 is formed.

In contrast to the figures shown above, in the FIG. 10 a basket 1 shown on its back not flat, but against the sound preferred direction of the speaker arched is formed. Such a slight curvature, which however should have a maximum angle α from the plane of not more than 20 °, preferably not more than 10 °, preferably not more than 5 °, may be helpful when a particularly flat design of the speaker, due to special installation situations, is necessary.

Basically, the speaker shown here with the execution of the FIG. 9 However, it should be noted that such a variation is also possible for all previously shown speakers.

The FIG. 11 shows an enlarged view of the magnet system of the FIG. 6 , This magnet system has a ring-shaped permanent magnet 5. On the back there is a pole plate, which is formed on both sides in front of the first yoke 13 and a second yoke 14. On the front side of the permanent magnet 5 there is a further pole plate, which together with the first and the second yoke form a first air gap 8 and a second inner air gap 15. In the outer air gap 8 dives a voice coil 9, which is responsible for the drive of the outer membrane 2, while immersed in the inner air gap 15, the voice coil 17 of the tweeter 24. The tweeter 24 is equipped with a high-tone membrane 18, which has at the outer edge via a small bead 19 which is connected to the pole plate 6. In addition, in FIG. 11, the electrical connections 31 for the voice coils, which are of course also present in all other loudspeaker systems but not explicitly shown, are shown. In the illustrated version, a damping element 27 is preferably used in the central region of the magnet system, which may for example consist of foam or soft rubber.

The rear view of an exemplary loudspeaker according to the invention is shown in FIG FIG. 12 shown. It essentially shows The basket 1 with the here symmetrically arranged rear openings 10 in the basket 1 and the four screw holes 11. It should be noted that, of course, other designs and contours of the openings are within the scope of the invention. In particular, it is also pointed out that the loudspeaker according to the invention not only has to have a round outer shape, but also oval, quadrangular or other per se known contours are possible.

In the Figures 13 and 14 is the supervision of a two-way speaker according to the invention shown, in which case the optional protective grille is not shown here for a better view. The FIG. 13 has additional four screw holes 11, for attaching the speaker, while in the FIG. 14 an embodiment of the basket 1 is shown without screw holes.

It should also be noted that the speaker according to the invention, which operates on the principle of the spring-mass system or the dynamic speaker, that has a voice coil in the air gap of a permanent magnet, compared to the conventional systems usually has a much larger voice coil and thus it allows the magnet system to be positioned within the voice coil.

This larger voice coil has the further advantage that the membrane is driven further on the outer diameter. As a result, the natural vibration behavior of the membrane is substantially stabilized or reduced and they can thereby be much flatter, lighter and thinner designed. The stroke of the voice coil is, for example, depending on the requirements and size, between 0.5 and 20 mm + / - and the diameter is 10 mm to 100 mm at a winding height from about 1 mm.

In an exemplary embodiment of the speaker with additional tweeter, the air gap for the outer membrane with coil between 0.1 mm to 3 mm and the air gap of the coil for the tweeter correspondingly larger, can be selected between 0.2 mm to 4 mm. This allows you to adjust the efficiency of the two systems together. The voice coil for the tweeter can advantageously have the following dimensions: diameter between 6 mm and 50 mm, height from 0.1 to 10mm +/- and a stroke of 0.1 to 5 mm +/-.

In addition, it should be noted that the voice coil used can be formed with one or more coil layers, preferably two-ply, and also with and without carrier.

Overall, therefore, an extremely flat speaker system is proposed by the invention, which is characterized by particularly simple and despite all very flat design. Due to the use of the very proven and effective dive coil system is also a very high effectiveness of the speaker and great acoustic quality to achieve.

LIST OF REFERENCE NUMBERS

1

basket

2

membrane

3

Beading

4

magnet system

5

permanent magnet

6

Front pole plate

7

Rear pole plate with yoke

8th

air gap

9

voice coil

10

opening

11

screw holes

12

Dust Cap

13

First yoke

14

Second yoke

15

Second air gap

16

Second membrane

17

Second voice coil

18

Tweeter diaphragm

19

Beading for tweeters

20

centering

21

Second bead of the outer membrane 2

22

Second permanent magnet

23

Second front pole plate

24

tweeter

25

Third permanent magnet

26

Third front pole plate

27

damping element

28

Mounting area of the first voice coil

29

guard

30

Membrane outer edge plane

31

electrical connection

32

Membrane outer edge

33

Sound propagation preferred direction

D

Outer diameter of the outer membrane

d

Diameter of the first voice coil

T

Construction depth of diaphragm and magnet system

α

Cone angle of the basket to the plane

Claims (29)

1. Loudspeaker, in the form of an electrodynamic sound transducer, comprising at least:

   a first magnet (5),

   a first diaphragm (2) with a diaphragm outer border (32) which spans a diaphragm outer border plane (30),

   a first bead (3), surrounding the first diaphragm (2), for flexibly mounting the first diaphragm (2),

   a first voice coil (9), which is indirectly or directly attached to the first diaphragm (2), and,

   a magnet system (4) with at least one first magnet (5) and at least one first annular gap into which the first voice coil dips, and also

   a supporting structure, basket (1), for holding the first magnet system (4) and the first diaphragm, wherein the first diaphragm is connected to the supporting structure by means of the first bead, and the supporting structure has a front oriented towards the diaphragm and a back oriented in opposition,

   characterized in that

   the first diaphragm (2) is of integral design and is produced at least partially forwards, in the direction of the sound preferential direction (33), has a curvature, and the region (28) of the first diaphragm (2), to which the first voice coil is attached, is arranged in front of the diaphragm outer border plane (30), wherein

   the first diaphragm (2) has a diameter (D) which is greater than the diameter of the first voice coil (d) which moves this diaphragm (2),

   the first annular gap (8) has a constricted parallel region in the direction of the diaphragm, and the entire magnet system is arranged in front of the supporting structure, basket (1).
2. Loudspeaker according to the preceding Claim 1, characterized in that the magnet system (4) intersects the diaphragm outer border plane (30).
3. Loudspeaker according to the preceding Claim 1, characterized in that the magnet system (4) is arranged in front of the diaphragm outer border plane (30).
4. Loudspeaker according to one of the preceding Claims 1 to 3, characterized in that at least one further diaphragm (18) is arranged inside the first diaphragm (2).
5. Loudspeaker according to one of the preceding Claims 1 to 4, characterized in that the magnet system (4) has at least one further annular gap (15) into which a respective further voice coil (17) for a further diaphragm (18) can dip.
6. Loudspeaker according to one of the preceding Claims 1 to 5, characterized in that the first diaphragm (2) has an internal bead (21) by means of which it is connected to the magnet system (4).
7. Loudspeaker according to one of the preceding Claims 1 to 6, characterized in that the magnet system (4) has at least one annular magnet (5) and at least one pole plate (6) which form the at least one air gap (8).
8. Loudspeaker according to one of the preceding Claims 1 to 7, characterized in that the magnet system has a plurality of annular magnets (5, 22, 25), a rear pole plate (7) and, for each magnet, a front pole plate (6, 23, 26), wherein the air gaps (8, 15) are arranged between the pole plates.
9. Loudspeaker according to one of the preceding Claims 1 to 8, characterized in that at least one diaphragm (2) has a centring element fitted.
10. Loudspeaker according to one of the preceding Claims 1 to 9, characterized in that the magnets (5, 22, 25) are respectively surrounded annularly by the associated voice coil (9, 17).
11. Loudspeaker according to one of the preceding Claims 1 to 10, characterized in that the magnet system (4) has pole plates (6, 7, 23, 26) comprising magnetic material.
12. Loudspeaker according to one of the preceding Claims 1 to 11, characterized in that at least one annular magnet (22) is situated inside a relatively large and at the same time outside a relatively small voice coil (9, 17).
13. Loudspeaker according to one of the preceding Claim 1 to 12, characterized in that an annular magnet (5) has at least two pole plates (6, 7), of which the rear pole plate (7) surrounds the magnet annularly and forms an outer and an inner air gap (8, 15) with the front pole plate (6).
14. Loudspeaker according to one of the preceding Claims 1 to 13, characterized in that at least one magnet is produced from neodymium - iron or neodymium - iron - boron or rare earths - cobalt, SmCo₅ or Sm₂Co₁₇, or hard ferrites.
15. Loudspeaker according to one of the preceding Claims 1 to 14, characterized in that at least one magnet is attached to the diaphragm basket at least by means of at least one screw and/or adhesive and/or at least one clamping element, snap in, clipped.
16. Loudspeaker according to one of the preceding Claims 1 to 15, characterized in that at least one diaphragm comprises foamed material, is preferably provided with a single-sided or double-sided barrier layer, preferably comprises aluminium foam and magnesium foam, polystyrene hard foam, PVC, polyolefin, polyurethane, polyester, Styrofoam or sandwich plates with a honeycomb structure.
17. Loudspeaker according to one of the preceding Claims 1 to 16, characterized in that at least one diaphragm (2) comprises specially shaped films or sandwich products, preferably comprising polyester, polyimide, Bextrenes, polycarbonate, aluminium, magnesium, polypropylene, paper, fibrous materials, carbon fibre, fibreglass or comprising hybrid products from these materials.
18. Loudspeaker according to one of the preceding Claims 1 to 17, characterized in that an inversely shaped dust cap, dome or cap (12) is arranged on a diaphragm (2).
19. Loudspeaker according to one of the preceding Claims 1 to 18, characterized in that at least one bead (3, 19, 21) is produced from rubber or coated foam material, fibrous materials or paper.
20. Loudspeaker according to one of the preceding Claims 1 to 19, characterized in that the basket (1) is produced from plastics or metal materials.
21. Loudspeaker according to one of the preceding Claims 1 to 20, characterized in that the basket (1) has openings (10) for physical coupling to be rear air volume, lining or housing.
22. Loudspeaker according to one of the preceding Claims 1 to 21, characterized in that the back of the basket (1) is flat.
23. Loudspeaker according to one of the preceding Claims 1 to 22, characterized in that the back of the basket (1) is in the form of a truncated cone, preferably with a pitch of no more than 20°, preferably no more than 10°, relative to the plane.
24. Loudspeaker according to one of the preceding Claims 1 to 23, characterized in that a protective grating (29) is provided in front of the diaphragms.
25. Loudspeaker according to one of the preceding Claims 1 to 24, characterized in that the ratio B/T or D/T of greatest breadth B or diameter D of the outer diaphragm (2) of the loudspeaker to greatest physical depth of the loudspeaker T in relation to the components diaphragm and magnet system is greater than 3/1, preferably greater than 5/1, preferably greater than 10/1.
26. Loudspeaker according to one of the preceding Claims 1 to 25, characterized in that at least one front pole plate (6, 23, 26) is arranged completely in front of the diaphragm outer border plane (39).
27. Loudspeaker according to one of the preceding Claims 1 to 26, characterized in that at least one permanent magnet (5, 22, 25) is arranged in front of the diaphragm outer border plane (39).
28. Loudspeaker according to one of the preceding Claims 1 to 27, characterized in that the magnet system (4) has no rear pole plate.
29. Loudspeaker according to one of the preceding Claims 1 to 28, characterized in that the outer bead (3) has a plurality of elevations in section.

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