Suspension device for a loudspeaker, and associated manufacturing method and loudspeakers

Abstract

The invention relates to a suspension device (1) for a loudspeaker comprising: - an outer edge (2); - an inner edge (3); - a suspension (4) extending between the outer and inner edges; the suspension being able to absorb movement stresses produced on the inner edge by means of a predetermined deformation of the suspension. According to the invention, the suspension comprises at least three distinct portions: a rotating mass (7); a first lip (8) attached to the end of the inner edge; and a second lip (9) attached to the end of the outer edge; the first lip and the second lip also being connected to the rotating mass such that the pistonic movements of the diaphragm cause the rotating mass of the suspension to rotate.

Description

[0001] DESCRIPTION

[0002] TITLE OF THE INVENTION: SUSPENSION DEVICE FOR LOUDSPEAKER, METHOD OF MANUFACTURING IT AND ASSOCIATED LOUDSPEAKER SPEAKERS

[0003] FIELD OF INVENTION

[0004] The invention relates to the field of acoustic equipment. It concerns a loudspeaker suspension device, and more specifically a suspension device connecting a loudspeaker chassis to a diaphragm. It also relates to a method for manufacturing the suspension device and to a loudspeaker comprising such a suspension device.

[0005] The invention relates more specifically to a new suspension device that offers advantages in terms of acoustic performance, particularly with regard to reducing the suspension's noise emission and symmetrizing its compliance, or more precisely, lowering distortion over a wide frequency range. This new suspension device is particularly well-suited to midrange drivers, tweeters, and / or full-range drivers, for example, in headphones.

[0006] STATE OF THE ART

[0007] Generally, a loudspeaker consists of a fixed chassis and a circular moving diaphragm mechanically connected to a coil through which a current flows, representing the acoustic signal to be generated. The loudspeaker also includes a magnetic field source, usually constant, which interacts with the current flowing through the coil to allow the coil, and therefore the diaphragm, to move.

[0008] The movement of the circular membrane relative to the frame is guided by an annular suspension device comprising an outer annular edge for attaching the suspension device to the frame and an inner annular edge for attaching the suspension device to the circular membrane. Typically, between these two annular edges, the suspension device includes an arc designed to guide the membrane during its movements and to ensure a seal between the front and rear faces of the membrane to prevent any acoustic short circuits.

[0009] However, when the moving assembly of the loudspeaker is set in motion, the suspension arc, which is made of a much more flexible material than the main diaphragm of the transducer, deforms with its own modes, thus acting as an uncontrolled parasitic diaphragm that can move in quadrature or in opposite phase with respect to the main diaphragm of the transducer.

[0010] This type of deformation severely degrades the acoustic quality of the transducer by generating more distortion at high frequencies, and a bumpy frequency response.

[0011] On the other hand, the shape of an arc suspension offers asymmetric compliance generating distortion at lower frequencies, the compliance being dependent on the asymmetric excursion which decreases with frequency.

[0012] To eliminate these resonance modes, it is known to increase the rigidity of the suspension bow. For example, US patent 7,463,749 proposes positioning three hemitoric protrusions under the suspension bow to increase its rigidity and limit its deformations.

[0013] However, the stiffness of the suspension arc determines the low resonant frequency of the loudspeaker, that is, its frequency response and distortion level at low frequencies, as well as the force required for the loudspeaker diaphragm to move when a command is applied. In an ideal loudspeaker, the diaphragm is free in air, and when a movement command is applied, it can respond directly by moving. The suspension system's primary function is to guide the diaphragm's translational movement, but it also acts as a brake on the diaphragm's movement because it must overcome the stiffness of the suspension arc to move in response to a command.Thus, the solution of US patent US 7,463,749, which consists of limiting the deformations of the suspension arc, is not optimal because it reduces the bandwidth and increases the distortion of the loudspeaker.

[0014] US patent application 2003 / 0228027 proposes positioning one or two partially toroidal protrusions on the suspension arch to limit its deformations. It also proposes limiting the rigidity of the suspension arch using a circular profile of crenellated protrusions. The crenellated profile of the protrusions limits the weight of the suspension arch and incorporates recesses whose length is determined empirically.

[0015] However, measuring and plotting a loudspeaker's frequency response curve is a complex and often time-consuming operation requiring specialized equipment such as an anechoic chamber. Therefore, empirically defining the shape of the frequency response curves associated with each loudspeaker range is a particularly complex, time-consuming, and expensive process. Analyzing diaphragm displacement is also a lengthy, complex, and expensive task, especially in the high-frequency range.

[0016] Furthermore, the protrusions in US patent application 2003 / 0228027 do not follow the circular shape of the suspension arc. The annular resonances induced by the notched shape must therefore be damped to avoid degrading the speaker's performance, thus limiting the effectiveness of this device.

[0017] The device of US patent application 2003 / 0228027 also presents a risk of large amplitude of displacement to the suspension modes due to the inertia of the mass of the protrusions, causing distortion.

[0018] The EP3284269A1 patent is satisfactory in terms of effectively absorbing these resonance modes; however, there is a need for improvement and refinement of this solution, specifically for high-frequency and wideband loudspeakers, typically midrange, tweeter, and / or wideband speakers, as well as headphone speakers. In these types of loudspeakers, specific resonance modes that interfere with the output sound always occur because they operate over a wide frequency range. Another area for improvement concerns the correction of distortion at the beginning of the frequency range.

[0019] Figure 1 represents a suspension according to the prior art requiring an improvement in frequency response. Figures 2 and 3 illustrate the solution provided by patent EP3284269A1, in which the suspension device 100 comprises protrusions 41 positioned along the suspension 40, this suspension 40 being fixed to the diaphragm 5 by means of an inner annular edge 30, and fixed to the chassis 6 by means of an outer annular edge 20.

[0020] The technical problem of the invention is therefore to effectively suppress parasitic resonance modes as well as parasitic sound emission from the loudspeaker suspension device, over a very wide frequency band including high frequencies.

[0021] DESCRIPTION OF THE INVENTION

[0022] The invention proposes to address this technical problem by forming a suspension comprising a central symmetry at the center of the rotating mass, so that it transforms the axial and radial parasitic resonances of the suspension into pivoting of the rotating mass.

[0023] This pivoting of the rotating mass, which takes place around its center of gravity, thus avoids the generation of parasitic acoustic pressure, while ensuring a symmetrical movement of the membrane.

[0024] The invention stems from the observation that, contrary to the technical prejudice of the person skilled in the art, it is possible to design a suspension with very little mobility along the axis of movement of the membrane, so that it generates almost no parasitic sounds, in particular for electrodynamic loudspeaker devices, such as midrange, treble and / or wideband loudspeakers.

[0025] Thus, instead of placing an outgrowth on the arc forming the suspension, a new innovative suspension system has been implemented, in which the movement of the membrane will initiate a beginning of axial displacement in a radial direction of the first part of the suspension which will directly set the rotating mass in motion and transmit the movement in opposite phase to the second part of the suspension.

[0026] Axial suspension movements along the radial direction are thus minimized because they are converted into pivoting of the rotating mass. Furthermore, since the second part of the suspension is fixed to the rotating mass opposite the first part, its movement will be out of phase, canceling out the sound generated by all parts of the suspension. This reduces distortion across all frequencies generated by a full-range, mid-range, and high-frequency speaker by linearizing the frequency response, resulting in a virtually flat response.

[0027] Thus, unlike other state-of-the-art suspensions, the device according to the present invention exhibits central symmetry around the center of gravity of the rotating mass of the suspension, offering symmetrical membrane compliance which reduces distortion at low frequencies.

[0028] According to a first aspect, the invention relates to a loudspeaker suspension device, said device comprising:

[0029] ■ an outer edge suitable for fixing the suspension device to a chassis;

[0030] ■ an inner edge suitable for fixing the suspension device with a membrane moving conventionally like a piston;

[0031] ■ a suspension extending between the outer and inner edges; said suspension being capable of absorbing displacement stresses produced on the inner edge due to the piston-like movement of the membrane by means of a deformation of the suspension. The invention is characterized in that the suspension comprises at least three distinct parts:

[0032] ■ a rotating mass;

[0033] ■ a first lip fixed to the end of the inner edge; and

[0034] ■ a second lip fixed to the end of the outer edge; the first lip and the second lip being also connected to the rotating mass so that the piston-like movements of the membrane cause a rotation of the rotating mass of the suspension.

[0035] In this way, parasitic resonance modes, which result in axial displacements of the first and second lips, are transformed into rotational motion of the rotating mass, leading to a virtually zero average displacement when all volume and / or surface displacements of the suspension are integrated. This limits parasitic sound pressure and reduces unwanted noise, particularly for high-frequency tweeters and full-range speakers.

[0036] According to one embodiment, a first connection point between one of the two lips and the rotating mass is located on an upper area of ​​said rotating mass, and a second connection point between the other lip and the rotating mass is located on a lower area of ​​said rotating mass, the upper and lower arrangement of these connection points being defined for a stable and unexcited state of the suspension device.

[0037] In this way, the axial displacements of the first and second lips along a radial axis including the radius of the suspension are transmitted appropriately to the rotating mass for their transformation into a rotary motion of the rotating mass, this rotary motion taking place around a rotary axis corresponding to a pivot axis containing the barycenter of the rotating mass.

[0038] The suspension device can take any known shape, i.e., annular, elliptical, oblong, or rectangular, without altering the invention. Naturally, the structure of the rotating mass and the lips can be adapted to the shape of the suspension device. For example, it is known to use suspensions with different length and width dimensions for suspension devices with oblong or rectangular shapes, so as to maintain compliance. With the invention, it is possible to adapt the same proportions for the mass and / or the length and thickness of the lips.

[0039] Preferably, the first and second connection points have central symmetry with respect to the center of gravity of the rotating mass, which allows for zero average displacement of the suspension when integrating the displacement over the volume and / or surface of the suspension, and which allows for symmetrical compliance of the membrane which reduces distortion at low frequencies.

[0040] Preferably, the mass of the rotating mass corresponds to at least 150% of the mass of the first lip and / or the second lip.

[0041] Preferably, the radial section of the first and second lips each has a radial section whose thickness is constant.

[0042] According to a second aspect, the invention relates to a method for manufacturing a loudspeaker suspension device according to the first aspect of the invention, comprising the following steps:

[0043] ■ to excite the inner edge of the suspension device;

[0044] ■ measure, during a characterization period, the displacements of the suspension relative to a stable state of the suspension;

[0045] ■ determine the geometric shape of the rotating mass and the location of the connection points of the first and second lips with said rotating mass, so that the axial displacements of the first and second lips are minimized and in opposite phase via actuation of the rotation of the rotating mass.

[0046] Preferably, the step of exciting the inner edge of the suspension device is carried out with a characteristic signal whose frequencies vary within a predetermined frequency range, preferably between 100 Hz and 20 kHz, so as to include the frequencies corresponding to tweeter-type loudspeakers and / or full-range headphone-type loudspeakers.

[0047] Preferably, the manufacturing process for a suspension device also includes the steps of

[0048] ■ to numerically model the dynamics of the suspension device as a function of measurements, during the characterization period, of the displacements of the suspension relative to a stable state of the suspension, and;

[0049] ■ Define the geometric shape of the rotating mass and the location of the connection points of the first and second lips with said rotating mass by numerical simulation of the previously defined model so as to minimize the axial displacements of the entire suspension. According to a third aspect, the invention also relates to a loudspeaker comprising a chassis and a diaphragm that can be moved in translation according to a piston-like motion, the loudspeaker having a suspension device according to the first aspect.

[0050] BRIEF DESCRIPTION OF THE FIGURES

[0051] The invention will be better understood upon reading the following description, given solely by way of example, and carried out in conjunction with the accompanying drawings, in which identical reference numerals designate identical or analogous features, and in which:

[0052] Figure 1 illustrates a schematic cross-sectional view of a prior art loudspeaker suspension device;

[0053] Figure 2 illustrates a schematic cross-sectional view of a second prior art loudspeaker suspension device;

[0054] Figure 3 illustrates a schematic perspective view of a loudspeaker including a prior art suspension device;

[0055] Figure 4 illustrates a schematic cross-sectional view of a loudspeaker suspension device according to the invention, attached to the diaphragm and chassis;

[0056] Figure 5 illustrates a schematic cross-sectional view of a loudspeaker suspension device according to one embodiment of the invention;

[0057] Figure 6 illustrates a schematic cross-sectional view of a loudspeaker suspension device according to one embodiment of the invention;

[0058] Figure 7 illustrates a schematic cross-sectional view of a loudspeaker suspension device according to one embodiment of the invention;

[0059] Figure 8 illustrates a schematic cross-sectional view of a loudspeaker suspension device according to one embodiment of the invention;

[0060] Figure 9 illustrates a schematic cross-sectional view of a loudspeaker suspension device similar to Figure 5, when the suspension device is in an excited state;

[0061] Figure 10 illustrates a schematic cross-sectional view of a loudspeaker suspension device similar to Figure 6, when the suspension device is in an excited state;

[0062] Figure 11 illustrates a schematic perspective view of a loudspeaker comprising a suspension device according to the invention;

[0063] Figure 12 illustrates a graph representing the compliance of a suspension of the prior art; and Figure 13 illustrates a graph representing the comparison between the compliance of a suspension of the prior art with the compliance of a suspension according to the invention.

[0064] DETAILED DESCRIPTION OF THE INVENTION

[0065] Figures 4 and 11 describe a suspension device 1 according to the invention, comprising an outer annular edge 2 fixed on a frame 6 and an inner annular edge 3 fixed on a circular membrane 5 movable in translation about the axis of revolution 16 of the membrane 5, a suspension 4 annularly connecting the two edges 2 and 3. The membrane 5, which is in the form of a diaphragm, is configured to move on frequencies contained within a frequency range associated with the suspension device 1. Alternatively, the suspension device 1 could take other forms, for example oblong, elliptical or rectangular, without changing the invention.

[0066] The excitation signal of the membrane 5 corresponds to a sinusoidal signal whose amplitude is constant and whose frequency is variable between a low frequency and a high frequency in the frequency range, for example in the frequency range 20Hz to 20KHz, therefore also including the frequencies relating to mid-range, high-frequency or wideband type speakers.

[0067] Figures 5 to 8 illustrate various embodiments of a suspension device 1 according to the invention, structured to attenuate parasitic resonance modes, thereby avoiding the generation of parasitic acoustic pressure while ensuring symmetrical compliance of the membrane 5. The suspension device 1 shown in Figures 5 to 8 is in a stable, unexcited state, i.e. in a configuration where the membrane is not vibrating.

[0068] Figures 9 and 10 respectively illustrate the suspension devices shown in figures 5 and 6 in an excited state, or more precisely in a state corresponding to a vibration of the membrane 5.

[0069] With reference to figures 5 and 11, the suspension device 1 according to the invention is illustrated according to a radial section plane of the suspension device 1, this plane being parallel and including the axis of revolution 16 of the membrane 5, this axis of revolution 16 being also that of the outer annular edges 2 and inner 3, and of the suspension 4.

[0070] More specifically, Figure 5 illustrates a suspension 4 comprising a rotating mass 7, a first lip 8 and a second lip 9. The first lip 8 comprises two ends: a first end 10 intended to be connected to the annular inner edge 3, and a second end connected to the rotating mass 7 at a first connection point 11.

[0071] Similarly, the second lip 9 also comprises two ends: a first end 12 intended to be connected to the outer annular edge 2, and a second end connected to the rotating mass 7 at a second connection point 13.

[0072] In practice, the thickness of the first and second lips 8, 9 is preferentially between 50 µm and 1 mm, and even more preferably between 80 µm and 1 mm. The thickness can, for example, be equal to 110 µm. The thickness of the first and second lips 8, 9 is constant, but this can also vary along the length of the first and second lips 8, 9, for example with a variation of the order of 5 to 20% compared to the initial thickness.

[0073] The suspension 4 according to the invention has central symmetry when the suspension 4 is in a stable unexcited state: the first and second connection points 11, 13 on the one hand, and the first and second lips 8, 9 on the other hand, are symmetrical with respect to the rotating axis 14 defining the pivot axis of the rotating mass 7, and also symmetrical with respect to the center of gravity of the rotating mass 7 included in the rotating axis 14.

[0074] As illustrated in Figure 11, this rotating axis 14 is perpendicular to the axis of revolution 16 of the membrane 5. In this Figure 11, the cutting plane 15 is used to extract the embodiments illustrated in Figures 5 to 10.

[0075] In practice, the first and second connection points 11, 13 on the one hand, and the first and second lips 8, 9 on the other hand are also symmetrical with respect to a radial cutting plane 15.

[0076] The annular suspension 4 as a whole is also a revolution of this cross-section illustrated in figure 5 around the revolution tax 16 of the membrane 5, as illustrated in figure 11.

[0077] The first and second connection points 11 and 13 are located respectively on an upper and lower zone of the rotating mass 7, the upper and lower zones corresponding respectively to the external and internal surfaces of the annular suspension 4. The external surface of the annular suspension 4 is understood to be that corresponding to the external surface of the loudspeaker.

[0078] According to an unrepresented variant, the arrangement of the connection points can be reversed. Thus, the first and second connection points 11, 13 are respectively located on a lower and upper area of ​​the rotating mass 7.

[0079] The rotating mass 7 is shown here as having a rectangular cross-section along the radial cutting plane. The rotating axis 14 is shown here as comprising the center of gravity of the rotating mass 7, or the center of mass of this rotating mass 7. The rotating mass 7 thus pivots about its center of gravity and about the rotating axis 14 as defined above. As previously stated, the center of gravity of the rotating mass 7 is also a point of symmetry for the arrangement of the first and second connection points 11 and 13.

[0080] Figure 9, corresponding to the device illustrated in Figure 5 in an excited state when membrane 5 begins to vibrate, illustrates the movements of suspension 4. The vibration of membrane 5 will induce an excitation of suspension 4.

[0081] When this suspension 4 is in an excited state, the first lip 8 will rotate the rotating mass 7 around its center of mass 14 by means of a first connection point 11. The rotating mass will directly transmit this motion in opposite phase to the second lip 9 by means of the connection point 13. Furthermore, when the rotating mass 7 and the lips 8-9 are made of different materials, the rotating mass 7 preferentially exhibits a stiffness greater than that of the lips 8 and 9. This stiffness can be characterized by a Young's modulus greater than or equal to the Young's modulus of the lips 8 and 9. Alternatively, the lips 8-9 and the rotating mass 7 can be made of the same material, the entire suspension then having the same Young's modulus.

[0082] Thus, the parasitic resonance modes, which generate the axial displacements of the first and second lips 8, 9, are attenuated much more effectively by the rotation of the rotating mass 7 in the present invention, avoiding the generation of parasitic acoustic pressure.

[0083] Distortion across all frequencies generated by a loudspeaker, whether full-range, mid-range, or tweeter, is thus reduced, linearizing the frequency response to achieve a flat response. The diaphragm also exhibits symmetrical compliance, reducing distortion at low frequencies.

[0084] With reference to Figure 12, the asymmetric compliance 17 of a prior art suspension 40 is shown, the compliance being expressed here in Newtons per millimeter as a function of the displacement field expressed in millimeters. This asymmetric compliance 17, with respect to its rest position, has an axis of symmetry 19 offset from the equilibrium axis 18, the equilibrium axis 18 corresponding to a zero displacement field. The suspension 4 according to the invention, on the other hand, has a symmetric compliance 20, whose axis of symmetry 19 coincides with the equilibrium axis 18, corresponding to the rest position, as shown in Figure 13.

[0085] In particular, the symmetry of the connection points to the rotating mass 7, and the positioning according to a central symmetry of the first and second connection points 11, 13 and of the first and second lips 8, 9 makes it possible to drastically reduce the resonances of the suspension 4.

[0086] These resonances of suspension 4 have the disadvantage of emitting acoustic pressure in opposite phase or in phase or in quadrature phase with the cone or diaphragm of the loudspeaker, or by acting as a second source of excitation of the cone and twisting or deforming the end of the diaphragm or cone if it is not sufficiently rigid.

[0087] The suspension device 1 according to the invention therefore allows the entire membrane or cone to no longer vibrate in opposite phase, this vibration causing "accidents" in the frequency response.

[0088] More specifically, the device 1 according to the invention makes it possible to avoid modal deformations of the suspension 4 according to at least the first four modes of vibration of the suspension 4. These vibrations, occurring axially along the axis of revolution 16 of the membrane 5 and / or the radial cutting plane 15, are out of phase with the membrane 5, cause "accidents" in the frequency response.

[0089] In practice, the axial displacements in opposite phase of the first and second lips 8, 9 and their transformations into rotation of the rotating mass 7 allow us to achieve an average displacement of the suspension 4 of zero when we integrate its displacement over the volume or surface of the suspension 4. This results in a near-zero acoustic pressure, limiting the parasitic sound generated by a suspension 4 according to the prior art, mainly avoiding the generation of parasitic acoustic pressure, and advantageously of parasitic sounds.

[0090] The presence of a single central axisymmetric rotating mass 7, in the case of a circular loudspeaker, connected by the first and second lips also avoids the distortion generated by the inertia of a plurality of masses or protrusions positioned along the suspension 4, inducing a non-symmetric compliance 17, as shown in figures 12 and 13, and which can be the source of distortion.

[0091] Figures 6 to 8 depict embodiments similar to that of Figure 5, except that the radial cross-section of the rotating mass 7 along the radial cutting plane can be square, oval, or circular, respectively. Also according to these figures, the operation of the suspension 4 and the displacement of the first lip 8, second lip 9, and rotating mass 7 are similar to the displacements of the suspension 4 illustrated in Figure 5 and explained above.

[0092] Figure 10 corresponds to the device illustrated in Figure 6 in an excited state when the membrane 5 begins to vibrate, the rotating mass 7 having a square radial section.

[0093] It is understood that other shapes are conceivable for the rotating mass 7, such as rotating masses having a radial section of polygonal shape or in general elliptical shape, without going out of the scope of the invention.

[0094] Thus, with the particular structuring of the suspension device 1 according to the invention, in particular with the presence of a rotating mass 7 actuated by the axial displacements of the suspension 4, it is possible to improve the frequency response of the loudspeakers by reducing distortion, and more particularly the frequency response of high-frequency loudspeakers of the tweeter type and wideband loudspeakers of the headphone type.

Claims

DEMANDS 1. Loudspeaker suspension device (1), said device comprising: ■ an outer edge (2) suitable for fixing the suspension device (1) with a chassis (6); ■ an inner edge (3) suitable for fixing the suspension device (1) with a membrane (5) moving conventionally like a piston; ■ a suspension (4) extending between the outer edge (2) and inner edge (3); said suspension (4) being capable of absorbing displacement stresses produced on the inner edge (3) due to the piston-like movement of the membrane (5) by means of a deformation of the suspension (4), characterized in that the suspension (4) comprises at least three distinct parts: ■ a first lip (8) fixed to the end of the inner edge (3); ■ a second lip (9) fixed to the end of the outer edge (2); and ■ a rotating mass (7) whose mass corresponds to at least 150% of the mass of the first lip (8) and / or the second lip (9); the first lip (8) and the second lip (9) also being connected to the rotating mass (7) by at least one connection point (11, 13) per lip (8, 9), so that the piston-like movements of the membrane (5) cause a rotation of the rotating mass (7) of the suspension (4). 2 Device according to claim 1, wherein a first connection point (11) between one of the two lips and the rotating mass (7) is located on an upper area of ​​said rotating mass (7), and a second connection point (13) between the other lip and the rotating mass (7) is located on a lower area of ​​said rotating mass (7), the upper and lower arrangement of these connection points being defined for a stable and unexcited state of the suspension device (1). 3 Device according to claim 2, wherein the first and second connection points (11), (13) have central symmetry with respect to the center of gravity of the rotating mass (7). 4 Device according to any one of the preceding claims, wherein the radial section of the first and second lips (8), (9) each has a radial section whose thickness is constant.

5. A method for manufacturing a loudspeaker suspension device (1) according to any one of claims 1 to 4, characterized in that it comprises the steps including: ■ excite the inner edge (3) of the suspension device (1); ■ measure, during a characterization period, the displacements of the suspension (4) relative to a stable state of the suspension (4); ■ determine the geometric shape of the rotating mass (7) and the location of the connection points of the first and second lips (8), (9) with said rotating mass (7), so that the axial displacements of the first and second lips (8), (9) is minimized and in opposite phase via the actuation of the rotation of the rotating mass (7). 6 Method of manufacturing a suspension device (1) according to claim 5, wherein the step of exciting the inner edge (3) of the suspension device (1) is carried out with a characteristic signal whose frequencies vary within a predetermined frequency range, preferably between 100 Hz and 20 kHz.

7. A method for manufacturing a suspension device (1) according to claim 5 or 6, wherein it comprises the steps of: ■ to numerically model the dynamics of the suspension device (1) as a function of the measurements, during the characterization period, of the displacements of the suspension (4) relative to a stable state of the suspension (4), and; ■ define the geometric shape of the rotating mass (7) and the location of the connection points of the first and second lips (8), (9) with said rotating mass (7) by numerical simulation of the previously defined model so as to minimize the axial displacements of the entire suspension (4). 8 Speakers including: ■ a chassis (6), and; ■ a membrane (5) that can be moved in translation according to a piston movement; characterized in that it comprises a suspension device (1) according to any one of claims 1 to 4.

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