EP0313560B1 - Membrane system with flexion-resistant rotationally symmetric plate for use as a sound reflecting or receiving element - Google Patents

Abstract

Membrane system with flexion resistant rotationally symmetric plate for use as a sound reflecting or receiving element for an acoustic transducer and applications of the membrane system. The task is to avoid essentially acoustic distorsion. The wall thickness (K) measured in an axial direction (1) along the plate should increase with raising values of a radial coordinate oriented towards the edge (r = RO), first up to beyond the half (RO/2) plate radius then decrease again, whereby the shape of the raising and falling curve of the wall thickness (K) along the radial coordinate (R) is constant up to a fixing area on the edge (R = RO) or tends to approximate to a constant progression. This membrane system can be used for all types of loud-speakers, and particularly also for compression chamber system.

Description

The invention relates to a membrane system with a plate according to the preamble of claim 1 and applications of the membrane system. In contrast to a ring, a plate is understood to mean a structure that has no inner edge.

The plate can be used as a membrane or membrane part for sound transducers, in particular loudspeakers of all kinds for the reproduction of speech or music, e.g. in a dome emitter, in a pressure chamber system or as the middle part of a loudspeaker cone or plate.

In such applications, undesired partial vibrations lead to distortions in the radiated sound vibrations.

From the German patent DE 31 23 098 C2 a membrane for electroacoustic transducer systems is known which is characterized as a vibration system by a predominant resistance inhibition; In this membrane, the inner portion is designed as a light, rigid or rigid, piston radiator-like vibrating body, which is driven by electromagnetic forces. The thickness (wall thickness) of the piston body-like vibrating body differs at different points, with an increase in thickness towards the drive point being provided in particular. This is particularly intended to achieve a low level of distortion.
The invention aims more towards a membrane system with a plate for use as a piston transducer with elastic edge clamping, the sound-radiating or absorbing surface of the plate being significantly larger than the corresponding surface of a flexible elastic edge ring (bead) used for edge clamping.

It is an object of the invention to provide a membrane system with a plate,

in which the distortions of radiated sound vibrations are low compared to the forced vibrations of their drive.

This object is achieved by the membrane system with the features of claim 1.
Advantageous further developments are given in claims 2 to 32. Applications of the membrane system according to the invention are claimed in claims 33 and 36.

The invention is based on calculations and tests which have shown that good mechanical properties can be achieved with the shape of the plate found, with the result that disruptive partial vibrations are largely avoided. In order to contain such partial vibrations, a certain course of the bending rigidity and the area moment of inertia must be maintained or approximated from the inside to the outside of the plate. In this case, stiffening struts or trusses are preferably dispensed with and instead a preferably solid shape is selected, to which foamed variants are also to be counted.

The preamble of claim 1 contains the feature that the plate is driven "near its edge". This means that the drive for the plate is located in an annular edge region of the plate, which preferably extends from 90% of the plate radius to the edge of the plate.

In the attachment zone at the edge mentioned in claim 1, it can be the zone for attaching the drive of the plate and / or for attaching an edge ring which the plate has on its edge and which in turn is clamped in place so that the guide Plate is guaranteed in the axial direction. However, the fastening zone can also be the zone where the plate is connected to a membrane, for example a cone membrane of a loudspeaker, the plate being the inner edge or the center of the membrane covered or bridged. Often the mounting zone where the plate is connected to the drive and the mounting zone where the plate is connected to an edge ring will have the same value of the radial coordinate.

Even in the embodiment in which the plate coaxially bridges the center of a membrane, the fastening zone where the plate is connected to the membrane and the drive can be at the same radial coordinate value.

• Figur 1 zeigt eine Hälfte eines Schnittes entlang eines Durchmessers eines Membransystems für einen Lautsprecher,
• Figur 2 ist ein vergrößerter Detailausschnitt aus Figur 1,
• Figur 3 zeigt den prinzipiellen Aufbau eines Lautsprechers im Schnitt,
• Figur 4 gibt genauer den Querschnittsverlauf des in Figur 3 verwendeten Membransystems an,
• Figur 5 zeigt die Anwendung der erfindungsgemäßen Platte in einem Kalottenlautsprecher, der im Schnitt dargestellt ist,
• Figur 6 gibt genauer den zugehörigen Querschnittsverlauf der in Figur 5 verwendeten Platte an und
• Figur 7 zeigt die Anwendung der erfindungsgemäßen Platte in einem Druckkammerlautsprecher, der ebenfalls im Schnitt dargestellt ist.

Exemplary embodiments of the invention are explained on the basis of the drawings.

• FIG. 1 shows a half of a section along a diameter of a membrane system for a loudspeaker,
• FIG. 2 is an enlarged detail section from FIG. 1,
• FIG. 3 shows the basic structure of a loudspeaker in section,
• FIG. 4 shows more precisely the cross-sectional profile of the membrane system used in FIG. 3,
• FIG. 5 shows the use of the plate according to the invention in a spherical speaker, which is shown in section,
• Figure 6 specifies the associated cross-sectional profile of the plate used in Figure 5 and
• Figure 7 shows the application of the plate according to the invention in a pressure chamber loudspeaker, which is also shown in section.

1 shows a half of a radial section through a membrane M, which is provided on its inner edge with a radial guide R _f (not mandatory) and an electromagnetic drive E, which acts in the direction of the membrane axis 1. The membrane is rigid, ring-shaped, rotationally symmetrical and conical. The drive is both plate and membrane drive.

The wall thickness H of the membrane M measured in the direction of the membrane axis 1 changes as a function of a radial coordinate r, which begins in the center of the membrane M with the value r = 0 and its on the outer edge Maximum value r = R reached. There, the membrane M merges into an edge ring R _r , which is flexible and ring-shaped and has the shape of a Sikke. (An edge ring with several beads can also be used.)
The wall thickness S of the edge ring ps, likewise measured in the direction of the membrane axis 1, decreases in the direction of a distance coordinate s from s = 0 to the outer edge. The edge ring R _r has on its outer edge an annular extension F, which serves to clamp the edge ring and thus indirectly the membrane M.

A rotationally symmetrical, rigid plate P is now glued inside the inner edge of the membrane M and serves as a spherical oscillator and dust protection for the drive E. The wall thickness K of this plate P changes depending on the radial coordinate r, which begins in the membrane axis 1 with the value r = 0 and runs for the plate P up to the limit value r = R₀ at the plate edge.

At r = R₀ the membrane M and the plate P are glued together in a manner not shown. The glue point is called the fastening zone. Their radial extent has been assumed to be negligibly small in the schematic FIG. 1. The plate P and the membrane M can also be made in one piece. Then the courses of the wall thicknesses K and H in the vicinity of the radial coordinate value r = R₀ deviate from the values that can be calculated in practice on the basis of theoretical considerations; because theoretically the wall thickness at r = R₀ is vanishingly small, which of course cannot be achieved in practice.

The plate P, driven by the drive E in the form of a voice coil, acts as a piston oscillator. Starting from the center (r = 0), its wall thickness K initially increases beyond half the plate radius (r = R₀ / 2) and then decreases again. Minimum values of the wall thickness K are thus reached in the plate axis 1 and at its edge at r = R₀. Between these minima, the wall thickness K itself, but also its increase or decrease (ie the differential quotient dK / dr) runs continuously or at least approximately continuously. In any case, this applies to one area to, which extends from r = 0.1 R₀ to the fastening teeth by r = R₀; because for the reasons given above, the fastening zone at the edge may have to be excluded when making statements about the wall thickness profile, and the same applies to a small area around the plate axis 1, where the wall thickness should theoretically be zero, but this is not practical in practice .

The wall thickness maximum K _x is therefore outside half the plate radius, but still within the radial coordinate value r _i for the drive E, which in the example shown is equal to R₀, the radial coordinate value for the edge of the plate.

Details of the preferred wall thickness profile of the plate P are explained below with reference to FIG. 6.

The plate and the membrane preferably consist of homogeneous or foamed material with a smooth surface; if a higher effort and thus a higher price is permitted, sandwich molds are preferred, as stated in claims 9, 10, 21, 22.

FIG. 2 shows an enlarged section 11 from FIG. 1, that is to say the fastening zone where the edge ring R _r is fastened to the outer edge of the membrane M. The attachment is achieved by a connecting ring V, which is glued to the membrane M and is integrally connected to the edge ring R _r, which is flexible and annular and has the shape of a bead. It has the wall thickness S, likewise measured in the direction of the membrane axis 1, which decreases in the direction of a distance coordinate s from s = 0 to the outer edge at s = R2, with a steady course or at least one steady course approximated. This course is given between the fastening zone V, on the one hand, where the membrane and the edge ring are fastened to one another, and, on the other hand, the outer edge of the edge ring, where it merges into the annular extension F after the wall thickness has reached a minimum. This extension F is used to clamp the edge ring and thus indirectly also the membrane M. The area around the distance coordinate value s = R₂ can also be referred to again as a fastening zone, which in turn is not taken into account in statements about the course of the wall thickness S for practical reasons.

The wall thickness S of the edge ring R _r in the region between the fastening zones V and F follows the relationship specified in claim 25 with a permissible deviation of ± 20%, the permissible deviation preferably being restricted in accordance with claim 26. The features specified in claims 27 to 29 should be observed with regard to the material density and the modulus of elasticity.

The loudspeaker shown schematically in section in FIG. 3 has a permanent magnetic ring magnet 2 with a soft magnetic core 3 and with a pole plate 4. In the air gap of the magnetic circuit thus formed, there is a diaphragm drive E 'on a cylinder Z which is guided by a radial guide Rf and via which a diaphragm M is driven. This is a so-called Nawi membrane (membrane that cannot be unwound) that deviates from the cone shape (FIG. 1), but nevertheless has a wall thickness profile corresponding to FIG. 1. The membrane shape resembles an exponential funnel. On this occasion, it should be noted that the regulations for the embodiments of the invention with membrane are also applicable to other basic membrane forms, e.g. on flat membranes or bell-shaped.

Basic shapes other than the arched one shown can also be used for the plate P (the edge of which is attached to the membrane at the maximum wall thickness).
In the example of Figure 3, the radial coordinate for the diaphragm drive E 'does not coincide with the radial coordinate for the edge of the plate. However, if one only looks at the plate P, it is actually directly driven at its edge by the membrane M, so the membrane is the "drive" for the plate.

The membrane M merges at its outer edge into an edge ring R _r , the extension F of which is attached to a loudspeaker basket 5, which in turn is connected to the pole plate 4. The statements made in connection with FIG. 1 apply to the edge ring.

FIG. 4 shows a more precise and preferred cross-sectional profile for The membrane and plate (each made of homogeneous material) of the loudspeaker according to FIG. 3, but using a conical membrane M. It can be seen that the plate P is attached to the wall thickness of the membrane M at a maximum H _m . One can see in the half-sided sectional view how the plate P coaxially bridges the central region of the membrane M. In this central area, the membrane drive E 'is attached, while the drive of the plate P is carried out by the membrane M at the location of the maximum wall thickness H _m . Especially since the maximum H _m is very flat here, the edge of the plate P need not necessarily be exactly at the location of the maximum H _m . The plate could, for example, have only 90% of its diameter or could be much larger than shown.

The course of the wall thickness H of the membrane is specified in claims 14 to 19 and 32, 33, while the material properties are described in claims 20 to 22.

The tolerance values + 50% or + 30% of claims 15 or 16 must be regarded as correspondingly reduced if the outer radius of the membrane 4r _in / 3 plus the tolerance values of 50% or 30% does not even reach. The tolerance range is preferably used only from -5% to + 10%.

Figure 5 shows an application example of the plate P according to the invention, which is used here in a spherical speaker, which in turn is shown in section. It has a permanent magnet 6 with a soft magnetic pot 7 and a yoke 8, supplemented by a soft magnetic ring 8a. Apart from clamping rings 9 to 13 and clamping screws 14 and 15, the remaining reference numerals correspond to those in the other figures. The same applies to the edge ring R _r as said in connection with FIG. 1. Its wall thickness decreases increasingly steeply starting from its fastening zone on its inner edge towards the fastening zone on the outer edge. With regard to the wall thickness profile of the plate P, reference is made to FIG. 6.

In the diagram according to FIG. 6, the profile of the plate P according to FIG. 5 is projected onto the r-axis, while such a projection has been dispensed with for the edge ring R _r .

The representation of the wall thickness K in FIG. 6 first shows that the wall thickness decreases increasingly steeply starting from the radial coordinate value r _{x of} its maximum K _x in the direction towards the edge (r = R₀) and in the opposite direction (r = 0). Also, the wall thickness W measured not parallel to the K-axis, but conventionally measured (like the wall thickness K) in the direction of the radial coordinate r towards the edge initially increases to over half the plate and / or drive radius and then decreases again. In the conventional measurement of the wall thickness, the angles with one another are the same, although not necessarily equal to 90 °. The straight line G is laid through the plate P in such a way that the smallest angles that can be measured on each side of the plate between the straight line and the plate surface are the same as one another. The distance between the intersection of the straight line and the plate surface corresponds to the conventionally measured wall thickness W, which also decreases increasingly steeply starting from the radial coordinate value r _{x of} its maximum value W _max = K _x in the direction of the radial coordinate r and in the opposite direction.

The wall thickness K, measured perpendicular to the radial coordinate r, decreases again clearly before reaching 90% of the maximum radial coordinate value of the plate P and before reaching 90% of the path from the plate axis to the drive E (FIG. 3).

For the wall thickness K as a function of the radial coordinate r, the relationship specified in claim 11 is preferred, the tolerance range being only ± 10% if possible. The exponents m and n are preferably selected according to claim 20, 21 or 22, depending on the material used.

The wall thickness profile S of the edge ring R _r is preferably such that the wall thickness S, starting from the fastening zone V on the inner edge of the edge ring in the direction of the fastening zone F on the outer edge, becomes increasingly steeper. Roughly speaking, the wall thickness profile of the edge ring R _{r is} qualitatively a reflection of the wall thickness profile of the plate P on the plate circumference, but in FIG. 6 only the plate profile is mirrored to the left of the maximum K _x , r _x .

The situation is similar with the wall thickness H of the membrane M in FIGS. 1, 3, 4: it results qualitatively from the reflection of the plate wall thickness K on the plate circumference.

FIG. 7 shows a further application example for the plate P according to the invention, namely a section through a pressure chamber loudspeaker with permanent ring magnet 16, yoke 17 and field plate 18. A soft magnetic cylinder 19 with a sound guide opening 20 is arranged in the center. The edge ring R _r is clamped with the aid of a disk ring 21, which in turn is held by a cover 22. From a pressure chamber located between the cylinder 19 and the plate P, the sound passes through the sound guide opening 20 for radiation. The plate is dome-shaped, adapted to the cylinder 19, with regard to the wall thickness having to be reverted to what was said above in connection with the other figures. The same applies to the edge ring R _r .

In the exemplary embodiment according to FIG. 7, it is remarkable that only a single opening is present between the pressure chamber and the sound outlet opening of the sound guide opening 20, namely only the sound guide opening 20 itself. In known pressure chamber loudspeakers, several channels lead from the pressure chamber to the sound guide opening. The sound vibrations coming through these channels had different phases, which were also dependent on the sample-dependent vibration modes that could form on the plate. The pressure chamber loudspeaker according to the principle shown in FIG. 7 emits the sound with greater phase purity, ie the phase curve over the frequency is more independent of the sample than before. This is important for achieving a good stereo impression when using such pressure chamber loudspeakers in stereo systems. The fictitious location of sound sources can be located better than before when using such pressure chamber loudspeakers. This also applies to loudspeakers other than pressure chamber speakers, provided that Plate (optionally with membrane and / or edge ring) is used according to the invention.

The amounts of the maximum wall thicknesses of the plate, the membrane and the edge ring are determined in a known manner either on the basis of empirical values with safety supplements or on the basis of calculations or tests. The strength of the selected material and its density (specific weight) must be taken into account, because the lower limit frequency of a sound transducer depends on the moving masses. In itself, one would like to choose the maximum wall thicknesses as small as possible, but must consider the minimum wall thicknesses with regard to the risk of fatigue fractures and the risk of distortion (e.g. due to membrane deformation). The maximum wall thicknesses must therefore be chosen in accordance with previous practice so that with the maximum deflection (which depends on the specified maximum load capacity of the sound transducer) of the plate or membrane or the edge ring, neither fatigue breaks nor clinking occur.

The best results in terms of the task can be achieved if the relationships are observed, as specified in claims 11, 18 and 25.

Claims (36)

1. Diaphragm system including a rotationally symmetrical bending resistant plate (P) as the sound radiating or receiving element in the form of a piston vibrator for an electroacoustic transducer, with the plate being driven near its edge (r = R₀) in the direction of the axis of symmetry which simultaneously is the axis (1) of the plate and the wall thickness (K) of the plate measured in the direction of the plate axis (1) initially increasing with increasing values of a radial coordinate r oriented toward the edge (r = R₀) to beyond one-half of the plate radius (R₀/2) and then decreasing again and the radial coordinate r being perpendicular to the plate axis (1), characterized in that
the curve for the increase and decrease (dK/dr) of the wall thickness (K) along the radial coordinate r up to a fastening zone at the edge (r = R₀) is steady or approaches a steady curve in sections; and
the maximum (K_x) of the wall thickness (K) of the plate (P) has a radial coordinate value (r_x) which is smaller than the radial coordinate value (r_i) of the region near the edge where the plate (P) is being driven.

2. Diaphragm system according to claim 1, characterized in that
the conventionally measured wall thickness (W) of the plate (P) increases toward the edge (r = R₀) as a function of the radial coordinate r to beyond one-half of the plate radius (R₀/2) and/or the plate driver radius and then decreases again.

3. Diaphragm system according to claim 1, characterized in that,
starting with the radial coordinate value (r_x) of its maximum (K_x), the wall thickness (K, W) decreases with increasing steepness in the direction toward the edge (r = R₀) and in the opposite direction.

4. Diaphragm system according to one of the preceding claims, characterized in that
the plate (P) is driven by a plate driver (E).

5. Diaphragm system according to one of the preceding claims, characterized in that
the wall thickness (K, W) of the plate (P) decreases again before it reaches 90 % of the maximum radial coordinate value (r = R₀).

6. Diaphragm system according to one of the preceding claims, characterized in that
the wall thickness (K, W) of the plate (P) decreases again before reaching 90 % of the path from the plate axis (1) to the plate driver (E).

7. Diaphragm system according to one of the preceding claims, characterized in that
the plate (P) is made of a homogeneous material, with the density of the material and/or the modulus of elasticity having a constancy, independent of the radial coordinate (r), as it is realized with conventional production methods.

8. Diaphragm system according to one of claims 1 to 6, characterized in that,
starting from a core region, the density of the material of the plate (P) increases in both axial directions (A, B).

9. Diaphragm system according to one of the preceding claims, characterized in that
the plate (P) is rotationally symmetrical only relative to its envelope and is made of a foamed core or a frame type or honeycomb type core formed between two cover layers.

10. Diaphragm system according to one of the preceding claims, characterized in that,
in dependence on the standardized radial coordinate x = r/R₀, in a region between x = 0.1 and the region near the edge where the plate (P) is being driven, the wall thickness (K) of the plate (P) measured in the direction of the plate axis (1) is subject to the rule that $${\text{K = K}}_{\text{x}}{\text{. (1 - x²)}}^{\text{m}}{\text{· x}}^{\text{n}}$$

including a tolerance range of ±20 % with reference to the maximum wall thickness, with m = 1/3 to 1/5, n = 2/3 to 2/5, where

K_x   is the maximum wall thickness and

R₀   is the value of the radial coordinate at the location where the plate (P) is being driven (Figure 6).

11. Diaphragm system according to claim 10, characterized in that
the tolerance range is only ±10 %.

12. Diaphragm system according to one of the preceding claims, characterized in that
the plate (P) coaxially bridges a region near the axis of a diaphragm (M), said region forming the driver for the plate, with the plate itself being driven in the bridged region (Figure 3).

13. Diaphragm system according to claim 12, characterized in that,
with increasing values for the radial coordinate r, the wall thickness (H) of the diaphragm measured in the direction of the plate axis (1) approaches a steady curve in sections or is steady in the region between fastening zones for the diaphragm driver (E′) and for an edge ring (R_r) and initially increases up to a maximum (H_m at r_m) to then remain constant or decrease again, with the radial coordinate value (r_m) at which the maximum (H_m) is reached lying closer to the inner fastening zone (r = r_i) than to the outer edge (r = R) of the diaphragm and, beginning at the inner fastening zone (r = r_i), the wall thickness (H) approaches, with constantly decreasing steepness, the maximum (H_m), with the edge (r = R₀) of the plate being fastened to the diaphragm in a region of the diaphragm (M) extending from the outer edge (R) of the diaphragm (M) up to 90 % of that radial coordinate value (r_m) where the diaphragm (M) reaches its maximum (H_m) wall thickness (H) (Figure 4).

14. Diaphragm system according to claim 13, characterized in that
the radial coordinate value (r = r_m) at the point where the diaphragm (M) reaches it maximum (H_m) wall thickness (H) is 4/3 of the radial coordinate value (r = r_im) of the fastening zone where the diaphragm (M) is fastened to its diaphragm driver (E′), within a tolerance range from +50 % to -15 %.

15. Diaphragm system according to claim 14, characterized in that
the tolerance range extends only from +30 % to -10 %.

16. Diaphragm system according to one of claims 13 to 15, characterized in that
the conventionally measured wall thickness (W_M) of the diaphragm (M) also approaches a maximum beginning at its inner fastening zone and with constantly decreasing steepness, said maximum meeting the same conditions of the respective one of claims 13 to 15 as apply for the wall thickness (H) measured perpendicularly to the radial coordinate r.

17. Diaphragm system according to one of claims 12 to 16, characterized in that
the wall thickness (H) of the diaphragm (M) measured perpendicularly to the radial coordinate r and including a tolerance range of ±20 % with reference to the maximum wall thickness is equal to $${\text{H}}_{\text{m}}{\text{(1 - 1/x²)}}^{\text{m}}{\text{. x}}^{\text{n}}$$

where

H_m =   the maximum diaphragm wall thickness, measured perpendicularly to the radial coordinate r;

x =   r/r_i;

r_i =   the radial coordinate value at the driver location of the inner fastening zone of the diaphragm;

m =   1/3 to 1/5;

n =   2/3 to 2/5.

18. Diaphragm system according to claim 17, characterized in that
the tolerance range is only ±10 %.

19. Diaphragm system according to one of claims 12 to 18, characterized in that
the diaphragm (M) is made of a homogeneous material and the density of the material and/or its modulus of elasticity have a constancy, independently of the radial coordinate r, as it is realized with customary production methods.

20. Diaphragm system according to one of claims 12 to 18, characterized in that,
beginning in a core region, the material density of the diaphragm (M) increases in both axial directions (A, B).

21. Diaphragm system according to one of claims 12 to 18, characterized in that
the diaphragm (M) is rotationally symmetrical only with respect to its envelope and is made of a foamed core or a core in the form of a framework or honeycomb between two cover layers.

22. Diaphragm system according to one of the preceding claims or according to one of claims 12 to 21, respectively, characterized in that
a flexible edge ring (R_r) is fastened to the edge of the plate (P) and to the outer edge of the diaphragm (M), respectively, for clamping in the diaphragm, with the wall thickness (S) of said ring, measured in the direction of the plate axis (1) decreasing steadily, or at least in a manner approaching a steady curve in sections as a function of a radial distance coordinate s, said decrease occurring between the fastening zone (V) where plate and diaphragm, respectively, as well as the edge ring are fastened to one another, on the one hand, and the wall thickness minimum at the fastening zone (F) at the outer edge of the edge ring, on the other hand, with the distance coordinate s extending perpendicularly to the plate axis (1) and counting from the inner edge (s = 0) to the outer edge (s = R₂) of the edge ring (Rr) (Figures 1, 5 and 6).

23. Diaphragm system according to claim 22, characterized in that,
starting from its fastening zone (V) at the inner edge (s = 0), the wall thickness (S) of the edge ring (Rr) decreases with increasing steepness in the direction toward the fastening zone (F) at the outer edge (s = R₂).

24. Diaphragm system according to claim 23, characterized in that,
in the region between the fastening zones (V, F), the wall thickness (S) of the edge ring (R_r), with a permissible deviation of +20 % with reference to the maximum wall thickness, is equal to $${\text{sm · |1 - (s/R₂)²|}}^{\text{1/3}}$$

where

S_m =   the maximum wall thickness of the edge ring (Rr);

R₂ =   the upper value of the distance coordinate s at the fastening zone (F) at the outer edge of the edge ring (R_r).

25. Diaphragm system according to claim 24, characterized in that
the permissible deviation is limited to ±10 %.

26. Diaphragm system according to one of claims 22 to 25, characterized in that
the density of the material of the edge ring (R_r), independently of the distance coordinate (s), has a constancy as it is realized with customary manufacturing methods.

27. Diaphragm system according to claim 26, characterized in that
the modulus of elasticity of the edge ring (R_r) also has a constancy, independently of the distance coordinate (s), as it is realized with customary manufacturing methods.

28. Diaphragm system according to claim 26 or 27, characterized in that
the constancy of the material density and of the modulus of elasticity also exists in the direction of the plate axis (1).

29. Diaphragm system according to claim 7 in conjunction with claim 10, characterized in that m = 1/3 and n = 2/3.

30. Diaphragm system according to claim 10 in conjunction with one of claims 8, 9, characterized in that
m = 1/5 and n = 2/5.

31. Diaphragm system according to claim 17 in conjunction with claim 19, characterized in that
m = 1/3 and n = 2/3.

32. Diaphragm system according to claim 17 in conjunction with one of claims 20, 21, characterized in that
m = 1/5 and n = 2/5.

33. Use of the diaphragm system according to one of claims 1 to 11 or 22 to 30, for a cap-type loudspeaker (Figure 5).

34. Use of the diaphragm system according to one of claims 1 to 11 or 22 to 30 for a pressure chamber loudspeaker (Figure 7).

35. Use according to claim 30, characterized in that
the plate (P) is dome shaped.

36. Use according to claim 30 or 31, characterized in that
the pressure chamber of the pressure chamber loudspeaker has only one sound guidance opening (20) arranged around the plate axis (1) for radiation of the sound (Figure 7).

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