Surround for a loudspeaker

Abstract

The invention relates to a surround (10) for a loudspeaker, preferably a planar loudspeaker, having a fastening region (14) extending in a fastening surface (12) and an elongate, preferably rectangular or oval, vibration region (16) arranged within the fastening region (14), wherein the contour of the vibration region (16) is designed such that sections of the vibration region (16) extend on different sides of the fastening surface (12).

Description

[0001] Surround for a speaker

[0002] The invention relates to a surround for a loudspeaker, preferably a planar loudspeaker.

[0003] DE 10 2018 124 261 A1 discloses a planar loudspeaker comprising a flat sound panel and a drive unit for driving the sound panel. The drive unit has a plate-shaped coil carrier with a coil formed thereon and a magnet device. The coil carrier is arranged in a gap between two magnet units of the magnet device. A bead (retaining element) can be omitted or can be provided only in sections.

[0004] For funnel-shaped and / or cone-shaped loudspeakers, round surrounds are used which have a uniform contour with a U-shaped cross-section.

[0005] The disadvantage is that the maximum excursion is small. A conventional surround with a semicircular cross-section would buckle at a large excursion due to its geometry, and the effective radiating area would be highly dependent on the diaphragm position, leading to very large nonlinear distortions. A buckled surround is particularly problematic, for example, with elongated diaphragms with small radii on the narrow side.

[0006] To reproduce low tones, a loudspeaker must exhibit a high volume displacement, where the volume displacement is calculated as the product of the effective radiating area and the excursion. This product must be as large as possible. Therefore, either a design with a large diaphragm area and a short excursion or a design with a small diaphragm area and a long excursion is possible. The design with a large diaphragm and a short excursion on the large front surface of a flat loudspeaker may seem simpler, but due to other physical limitations, it cannot achieve the same performance as with lateral diaphragms.

[0007] Due to the flat cabinet, the volume inside the speaker is very small, requiring very powerful drives to achieve the volume shift. However, the force with which the drives move the diaphragm also acts in the opposite direction on the cabinet, which, in turn, is not particularly rigid in this direction due to its flatness.

[0008] As experiments have shown, it is certainly possible to achieve volume shifts in a flat cabinet with a large diaphragm, but the cabinet would then vibrate so severely that the loudspeaker cannot be used in this way. These forces can only be counteracted by two diaphragms positioned one behind the other, rotating in opposite directions. While the drives can be nested side by side to some extent, the installation depth would still be too large for acceptable volume shifts.

[0009] In the design with a narrow diaphragm mounted on the side of the speaker, the drive unit loads the speaker cabinet along the rigid side, allowing a symmetrical, force-cancelling design with opposing, sequentially positioned diaphragms without changing the overall depth. The challenge here, however, is achieving the large diaphragm excursion required by the small radiating surface.

[0010] For low-distortion reproduction, the surround must be able to cover the required excursion range without mechanically buckling and without the radiating area changing significantly across the excursion range. The effective radiating area is defined as the quotient of volume displacement and the diaphragm amplitude. A change in this radiating area across the diaphragm's excursion position leads to nonlinear distortion. If the diaphragm is moved at a constant speed from its minimum to its maximum position, the volume displacement per time is constant for an ideal surround and diaphragm.

[0011] Mathematically, the effective radiating area can be considered as the area integral of the position change across the membrane surface and surround surface in the direction of the normal vector of the respective surface segment per position change of the membrane surface. The shape and direction of movement of the partial surfaces are irrelevant, since the normal vector is a function of the area.

[0012] Conventional surrounds cannot be used in narrow installation widths. For example, in planar loudspeakers, where the diaphragms are positioned on the narrow sides, the installation widths are extremely narrow. Therefore, a high excursion is required here.

[0013] It is therefore an object of the invention to provide a surround for a loudspeaker, a system comprising a surround and a membrane, and a loudspeaker in which a high maximum excursion is achieved.

[0014] This problem is solved by the subject matter of the independent claims.

[0015] According to the invention, the surround is suitable for a loudspeaker or can be used for this purpose.

[0016] The loudspeaker can preferably be a planar loudspeaker, i.e. a flat loudspeaker.

[0017] The bead preferably comprises or consists of a rubber material. The rubber material can be, for example, a relatively hard and / or vulcanized rubber. This withstands the high internal pressure in the housing and therefore does not bend or buckle accidentally. The bead has a fastening area extending into a fastening surface, preferably a fastening plane.

[0018] The mounting surface is preferably flat. Alternatively, it can be curved and / or bent.

[0019] For example, the surround is attached to the mounting area, preferably directly to the loudspeaker, e.g. a loudspeaker basket.

[0020] The fastening area preferably includes an outer edge or an outer edge of the bead.

[0021] Preferably, the surround completely surrounds a drive of the loudspeaker.

[0022] An elongated, preferably rectangular or oval, vibration area is arranged within the fastening area.

[0023] The term "rectangular" should be understood broadly. It also includes shapes that are essentially rectangular but have rounded corners, for example.

[0024] Preferably, the vibration region is formed as a frame, ring, or edge region of a recess or membrane. For example, the bead may have a recess and / or a membrane on its interior.

[0025] For example, the bead as a whole can have an elongated, preferably rectangular or oval, outer contour and / or an elongated, preferably rectangular or oval, outer circumference. The outer contour and / or the outer circumference can preferably be located in the mounting surface. The oscillation region can be set into vibration, for example, by the drive, preferably in a vibration plane oriented perpendicular to the mounting surface. The vibration plane can, for example, run parallel to a direction of movement of the oscillation region.

[0026] Preferably the contour is uneven.

[0027] The contour of the vibration region is designed such that the vibration region extends in sections on different sides of the fastening surface, preferably the fastening plane.

[0028] The contour of the vibration area can extend perpendicular to the mounting surface and / or parallel to the vibration plane.

[0029] The cross-section of the vibration region can preferably extend partially or completely above and partially or completely below the mounting surface. For example, the contour can protrude upwards above the mounting surface in one section and downwards below the mounting surface in another section.

[0030] The vibration range extends in sections on different sides of a preferably central longitudinal cross-sectional area of ​​the bead.

[0031] The special shape of the surround enables an extremely high maximum stroke with a narrow installation width and minimal changes in the effective radiation area.

[0032] The bead is preferably designed in such a way that the curvatures can bend and / or unfold in a controlled manner over a large stroke, while the effective radiating area remains virtually constant throughout the stroke. The shape or contour of the bead can preferably be calculated or (numerically) optimized using a computer simulation.

[0033] The surround according to the invention enables an extremely high maximum excursion with a narrow installation width, as well as low distortion and / or minimal changes in the effective radiating area, which is currently the only option for a narrow speaker for the low-frequency range. Thus, a large volume shift is required for the bass, which is achieved through the large excursion.

[0034] The surround is very resistant to the high internal pressure of the housing and does not bend due to its shape and contour.

[0035] Further developments of the invention can also be found in the dependent claims, the description and the accompanying drawings.

[0036] According to one embodiment, the contour is axially symmetric.

[0037] To prevent the surround from pulling the membrane to one side or twisting the membrane, the surround is preferably constructed with double symmetry, which, due to the symmetry, ensures a total force or torsional moment of 0 Newton or 0 Newton meters, regardless of the membrane position.

[0038] The bead can, for example, consist of four segments arranged symmetrically along two axes through the center. Each individual segment can, for example, consist of three larger sinusoidal support lines that run approximately parallel to the edge of the bead. The support lines can, for example, have a period of approximately one-quarter or one-sixth of the circumference of the bead.

[0039] Preferably, the two long sides of the bead are constructed identically. For example, each long side can have at least one elevation and at least one valley, preferably exactly two valleys. Alternatively or additionally, the two short end sides of the bead can also have the same structure. For example, each long side can have at least one elevation.

[0040] The basic shape of the contour is preferably wavy. The peaks and valleys can themselves be jagged and / or wavy. The contour is therefore preferably irregular.

[0041] For example, additional, smaller sinusoidal waves with a significantly higher frequency can be located on the support lines. These elements serve to stiffen the tips of the bead and further increase the maximum possible stroke range.

[0042] Due to the shape or contour of the surround, the surround exerts a different force on the membrane at each point where it is in contact with the membrane.

[0043] According to a further embodiment, the contour has at least in sections a V- and / or W-shaped cross-section, preferably at right angles to the fastening surface.

[0044] Preferably, V- and W-shaped sections can alternate. This can, for example, make the contour uneven.

[0045] According to a further embodiment, the contour is wider in the area of ​​the short end faces of the bead than in the area of ​​the long sides of the bead.

[0046] Preferably, the width of the contour is uneven.

[0047] For example, widening the end faces results in advantageous bending behavior with a large maximum deflection range. According to another embodiment, the short end faces of the bead are rounded and / or semicircular.

[0048] According to a further embodiment, the bead has a central recess.

[0049] The recess can, for example, be elongated, preferably rectangular or oval.

[0050] The bead itself can therefore be designed as a frame, ring or edge area of ​​a recess.

[0051] According to a further embodiment, the bead has a fastening device for a membrane.

[0052] The fastening device can, for example, have an inner edge or be designed as an inner edge. The membrane can be attached, e.g., glued, to the inner edge, for example, using a fastening means, e.g., an adhesive.

[0053] The membrane preferably comprises or consists of a rigid material, for example a metal material, e.g. aluminum, a plastic material, e.g. polypropylene, and / or a fiber composite material, e.g. carbon.

[0054] It's also conceivable to dispense with the diaphragm and instead construct the speaker with a surround. This would further increase the maximum possible excursion per speaker width.

[0055] The invention further relates to a system comprising a bead according to the invention and a membrane arranged within the bead. The bead can preferably have a fastening device, e.g., an inner edge, for the membrane. The membrane can be attached, e.g., glued, to the inner edge, for example, via a fastening means, e.g., an adhesive.

[0056] The membrane preferably comprises or consists of a rigid material, for example a metal material, e.g. aluminum, a plastic material, e.g. polypropylene, and / or a fiber composite material, e.g. carbon.

[0057] Finally, the invention relates to a loudspeaker, preferably a planar loudspeaker, with at least one surround according to the invention and / or a system according to the invention.

[0058] The loudspeaker may have at least one loudspeaker basket. Preferably, several loudspeaker baskets are provided.

[0059] The loudspeaker basket, surround, and / or diaphragm can preferably be arranged on a narrow side of the loudspeaker. Preferably, several loudspeaker baskets, surrounds, and / or diaphragms are provided. These can preferably be arranged on different sides of the loudspeaker.

[0060] For example, the surround is or is attached to the mounting area, preferably directly to the loudspeaker, e.g. the loudspeaker basket.

[0061] The loudspeaker preferably has a drive. The drive, which is preferably arranged in the loudspeaker frame, comprises at least one magnet and at least one coil.

[0062] The magnet can, for example, have different magnetization or polarity in certain sections. Alternatively, at least two differently magnetized or polarized magnets can be provided. The coil is preferably flat. For example, the coil can have a width between 1 mm and 10 mm, e.g., 4 mm.

[0063] The coil may preferably have at least one turn, wherein the turn may extend around a coil core.

[0064] An outer side of the winding opposite the coil core can, for example, have a mounting area for attachment to the loudspeaker. The coil is preferably attached to the loudspeaker exclusively via this mounting area.

[0065] The winding can thus be attached, e.g. glued, directly to the loudspeaker, e.g. the membrane and / or a centering device or a holder of the centering device.

[0066] A coil carrier is preferably not provided here.

[0067] The winding can, for example, be band-shaped and / or have a rectangular cross-sectional area.

[0068] For example, the winding comprises or consists of an aluminum material and / or a copper material.

[0069] Preferably, the winding further comprises an insulating layer, preferably an anodized layer and / or an adhesive lacquer layer.

[0070] The winding preferably consists of an anodized aluminum strip. The anodized layer can have a thickness between 1 pm and 10 pm, e.g., 4 pm.

[0071] The anodized layer electrically insulates the coil windings from one another. The coil core can, for example, contain or consist of air and / or a plastic material, preferably glass-fiber reinforced.

[0072] With a coil core made of air, there's essentially no solid core at all. In this case, a strong connecting element can be helpful, ensuring the coil maintains its desired shape.

[0073] Preferably, the surround completely surrounds the loudspeaker drive.

[0074] All aspects, embodiments, and features of the invention described here can be combined with each other, preferably independently of the specific embodiment in which they are mentioned. Preferably, all subject matter of the dependent claims can be combined with each other and with each subject matter of the independent claims.

[0075] The invention is described below by way of example with reference to the drawings.

[0076] Fig. 1 is a perspective view of an embodiment of a system according to the invention with a surround, a membrane and a loudspeaker basket,

[0077] Fig. 2 is a perspective view of a coil with attached

[0078] Membrane,

[0079] Fig. 3 is a perspective view of an embodiment of a bead according to the invention,

[0080] Fig. 4 is a sectional view of the bead according to Fig. 3, and Fig. 5 is a further sectional view of the bead according to Fig. 3.

[0081] First, it should be noted that the illustrated embodiments are purely exemplary in nature. Individual features can be implemented not only in the combination shown, but also individually or in other technically feasible combinations. For example, the features of one embodiment can be combined in any way with features of another embodiment. Preferably, the number of recesses, mounting recesses, and / or beads in the loudspeaker frame is arbitrary.

[0082] If a figure contains a reference symbol that is not explained in the immediately corresponding description, reference is made to the corresponding preceding or following explanations in the figure description. Thus, the same reference symbols are used for identical or comparable components in the figures and these are not explained again.

[0083] Fig. 1 shows a surround 10 for a loudspeaker, preferably a planar loudspeaker, having a fastening area 14 extending in a fastening surface 12 shown in dashed lines.

[0084] The fastening area 14 corresponds to an outer edge of the bead 10.

[0085] An elongated vibration region 16 is arranged within the fastening region 14.

[0086] The bead 10 has a central recess 36 in which a membrane 18 is arranged.

[0087] The surround 10 is attached to a loudspeaker frame 20. The loudspeaker frame 20 has an angled base body 22 and two, preferably identical, recesses 24 for loudspeaker drives. For better visibility, no loudspeaker drive is shown in the right-hand recess 24. The loudspeaker frame 20 has a mounting section 26 for the direct attachment of a surround 10.

[0088] The fastening section 26 corresponds to an edge of the recess 24.

[0089] The surround 10 is fastened, for example glued, directly to the fastening section 26 of the loudspeaker basket 20 via the fastening area 14.

[0090] To attach the loudspeaker basket 20 to a loudspeaker enclosure, the loudspeaker basket 20 may have mounting recesses 28. The mounting recesses 28 may, for example, be formed as hexagonal openings.

[0091] The fastening recesses 28 can be used, for example, for riveting rivet nuts, which are then used to fasten the loudspeaker housing with the aid of screws.

[0092] As can be seen in Fig. 2, a coil 30 with a coil core 32 and a plurality of windings 34 (the individual windings are not shown for illustrative purposes) can be attached, for example, glued, directly to the membrane 18. Furthermore, the coil 30 can be attached, for example, glued, to a holder 35 of a centering device.

[0093] In Fig. 3 to Fig. 5 it is shown that the bead 10 has a central recess 36.

[0094] Furthermore, the bead 10 has a fastening device 38 for the membrane 18.

[0095] The fastening device 38 corresponds essentially to an inner edge of the bead 10, which extends around the central recess 36. The membrane 18 can be directly attached, e.g., glued, to the fastening device 38.

[0096] The contour of the vibration region 16 is designed such that the vibration region 16 extends in sections on different sides of the fastening surface 12.

[0097] The vibration range may have several peaks 40 and valleys 42.

[0098] The basic shape of the contour is preferably wave-like. The elevations 40 and valleys 42 can themselves be jagged and / or wavy. The contour is therefore preferably irregular.

[0099] In the area of ​​the short end faces, the contour of the bead 10 is wider than in the area of ​​the long sides of the bead 10.

[0100] As can be seen in the sectional views in Fig. 4 and Fig. 5, the cross-section of the contour is V- or W-shaped at least in sections.

[0101] List of reference symbols

[0102] bead

[0103] Mounting surface Mounting area Vibration area Membrane

[0104] Loudspeaker basket Base body Recess Mounting section Mounting recess Coil

[0105] Coil core Winding Bracket Central recess Fastening device Elevation Valley

Claims

Claims 1. A surround (10) for a loudspeaker, preferably a planar loudspeaker, comprising a fastening region (14) extending in a fastening surface (12), preferably a fastening plane, and an elongated, preferably rectangular or oval, vibration region (16) arranged within the fastening region (14), wherein the contour of the vibration region (16) is designed such that the vibration region (16) extends in sections on different sides of the fastening surface (12).

2. Bead (10) according to claim 1, characterized in that the contour is axially symmetrical.

3. Bead (10) according to claim 1 or 2, characterized in that the contour has at least in sections a V- and / or W-shaped cross-section.

4. Bead (10) according to one of the preceding claims, characterized in that the contour is wider in the region of the short end faces of the bead (10) than in the region of the long sides of the bead (10).

5. Bead (10) according to one of the preceding claims, characterized in that the short end faces of the bead (10) are rounded and / or semicircular.

6. Bead (10) according to one of the preceding claims, characterized in that the bead (10) has a central recess (36).

7. Bead (10) according to one of the preceding claims, characterized in that the bead (10) has a fastening device (38) for a membrane (18).

8. System with a bead (10) according to one of the preceding claims and a membrane (18) arranged within the bead (10).

9. Loudspeaker, preferably planar loudspeaker, with at least one surround (10) according to one of claims 1 to 7 and / or a system according to claim 5.

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