OMNIDIRECTIONAL DIFFUSION ACOUSTIC SPEAKER AMPLIFIED BY A VIBRATING WOODEN BLADE

Abstract

OMNIDIRECTIONAL DIFFUSION ACOUSTIC ENCLOSURE AMPLIFIED BY A VIBRATING WOODEN BLADE The invention relates to an acoustic enclosure (100) comprising a box (200) having a lower face (210) having a perimeter P1; an acoustic insulator (300) arranged in said box; at least one loudspeaker (400) arranged in said box and oriented towards said lower face (210) in a first initial direction of propagation; a wooden blade (500) arranged opposite said lower face (210) and having a perimeter P2 extending along at least the dimensions of the perimeter P1 of said lower face (210), so as to oppose the initial direction of propagation of the sound waves and transform this into a radial and omnidirectional direction of propagation by vibration of said blade (500);at least one elastic support (600) mechanically connecting said airtight box (200) with said wooden blade (500) and configured to maintain a distance D1, representative of the gap between said box (200) and said blade (500). Figure for the abbreviation: Figure 1A;

Description

Title of the invention: OMNIDIRECTIONAL DIFFUSION ACOUSTIC ENCLOSURE AMPLIFIED BY A VIBRATING WOODEN BLADE Technical field of the invention

[0001] The invention relates to the field of sound diffusion, particularly with the use of a sound enclosure incorporating loudspeakers. More specifically, the invention concerns a sound enclosure enabling the omnidirectional diffusion of a sound wave by vibration of a wooden blade. Technological background

[0002] In the field of sound diffusion, the most commonly used directional loudspeakers project sound in a targeted and directional manner. The commonly used loudspeakers typically include drivers integrated into an enclosure, arranged in a line or coaxially.

[0003] Although they can offer satisfactory listening and sound reproduction qualities in open and controlled environments, known systems have significant limitations in crowded or large spaces, where physical obstacles may impede sound.

[0004] The main drawbacks of existing systems are the formation of "acoustic shadow zones" where sound quality is poor or nonexistent because the sound is not diffused omnidirectionally, or the uneven diffusion of sound frequencies, which can lead to sound distortion in certain areas. Furthermore, most known and used sound reinforcement systems often encounter difficulties in effectively circumventing obstacles in space.

[0005] In order to provide a more pleasant and balanced listening experience and to compensate for these "acoustic blind spots," one of the solutions frequently used is to multiply the audio equipment and loudspeakers in different locations. This results in increased installation and maintenance costs, as well as increased sound overlap, leading to phase problems and uncontrolled reverberation.

[0006] Another solution involves the use of omnidirectional sound-dispersing loudspeakers. Existing omnidirectional loudspeakers often use radial resonators or dome technology to disperse sound in all directions. These systems have enabled significant advances in low-frequency diffusion, but remain limited in several aspects, particularly in large rooms or crowded environments.

[0007] These aspects also relate to limited sound diffusion, a lack of sound homogeneity and sound diffusion that is often too focused and lacking in directivity.

[0008] To compensate for the shortcomings in sound coverage of existing systems, it is necessary to significantly increase the power required to fill a sound space. This results in increased energy demand, with a considerable cost due to the proliferation of loudspeakers in complex and cluttered environments, ultimately contributing to a potentially higher carbon footprint in addition to the potential harm to listeners' hearing health.

[0009] Very high-fidelity systems also offer loudspeakers with omnidirectional diffusion and that limit sound wave reverberations in the environment. However, these systems are very expensive and are mostly associated with highly complex digital signal processing technologies.

[0010] Furthermore, these digital approaches do not use any physical element for the omnidirectional diffusion of sound.

[0011] There is therefore a need to propose an acoustic enclosure to solve the problems mentioned. Objectives of the invention

[0012] The invention aims to provide an acoustic enclosure comprising a mechanical omnidirectional diffusion element interacting with loudspeakers.

[0013] The invention also aims to provide, in at least one embodiment, an acoustic enclosure enabling the reduction of sound reverberations.

[0014] The invention also aims to provide, in at least one embodiment, an acoustic enclosure ensuring optimal energy efficiency while preserving sound quality.

[0015] The invention also aims to provide, in at least one embodiment, an acoustic enclosure that amplifies sound waves without requiring additional energy.

[0016] The invention also aims to provide, in at least one embodiment, an acoustic enclosure allowing optimal reproduction of the sound spectrum independently of the size of the space.

[0017] The invention also aims to provide, in at least one embodiment, an acoustic enclosure ensuring the protection of a listener's hearing. Description of the invention

[0018] To this end, the invention relates to an acoustic enclosure comprising: - a hermetically sealed box having at least one lower face and one upper face spaced apart along an axis called the transverse axis, said lower and upper faces each having a perimeter PI; - acoustic insulation arranged in said airtight box; - at least one loudspeaker arranged in said enclosure and oriented to emit a sound wave towards said lower face in a first direction, called the initial direction of propagation; - a wooden blade arranged outside said box opposite said lower face and having a perimeter P2 having dimensions greater than or equal to the perimeter PI of said lower face, so as to intercept said sound waves circulating along said initial direction of propagation and diffuse them radially in the plane formed by said blade, in order to obtain an omnidirectional diffusion of sound waves by vibration of said blade; - at least one elastic support mechanically linking said airtight box and said wooden blade and configured to maintain at least a distance DI between said box and said blade.

[0019] For the purposes of this invention, a hermetic enclosure is defined as a closed and sealed enclosure.

[0020] For the purposes of this invention, it is also understood that the transverse axis along which the lower and upper faces of the enclosure are spaced corresponds to an axis perpendicular to the respective planes formed by said lower and upper faces.

[0021] In addition, said wooden blade is arranged parallel to said lower face, outside said box.

[0022] The invention thus proposes an acoustic enclosure whose properties are based mainly on the interaction between the wooden blade and said enclosure.

[0023] The wooden blade is a blade made from tonewood selected for its natural acoustic properties. It is a blade treated in such a way as to guarantee a relatively smooth surface, without apparent roughness, to ensure optimal acoustic performance.

[0024] When the loudspeakers emit a sound wave towards said blade, the blade then begins to vibrate according to the sound frequency reaching it. The sound wave from the loudspeakers in the enclosure is a wave directed along an initial propagation direction from the underside of said enclosure towards the wooden blade.

[0025] Furthermore, the wooden blade is made of a wood known for its acoustic properties and allows sound waves to be amplified without additional energy input. Thus, at the same power level compared to a traditional speaker, it is not necessary to drastically increase the sound volume. The speaker is designed to provide sound coverage of the space. This results in better energy efficiency and helps reduce the risk of hearing damage to the listener.

[0026] When the speaker is switched on, this results in a vibration and undulation of the wooden blade, in which the sound waves then diffuse radially through the wood of the blade until they reach the periphery P2 of the blade and then the surrounding environment. This results in omnidirectional sound diffusion through vibration of the wooden blade interacting with the loudspeakers.

[0027] The elastic supports can be damping elements of the "silent block" type and allow the wooden blade to be held in place while permitting its vibration synchronously with the loudspeakers. The interaction between the enclosure, said at least one loudspeaker, the elastic supports, and said wooden blade allows the blade to undulate while ensuring its stability. The elastic supports hold the wooden blade while allowing vibration synchronous with the waves produced by the loudspeakers. These supports guarantee the mechanical stability of the blade while preserving the vibrational freedom necessary for optimal sound diffusion.

[0028] The acoustic enclosure according to the invention diffuses sound omnidirectionally. This is made possible by the wooden blade, which, placed in front of the loudspeakers, acts as a diffuser, allowing the sound to propagate uniformly, without distortion or loss of quality, even in crowded environments. The acoustic enclosure according to the invention does not include any vents or openings on the cabinet; it is a sealed enclosure in which the wooden blade acts as an acoustic resonator.

[0029] Upon receiving sound waves from the loudspeakers, the blade begins to vibrate in order to amplify and redistribute the vibrations homogeneously in space.

[0030] Advantageously and according to the invention, said hermetic box comprises an internal partitioned structure extending between said lower and upper faces so as to define at least one compartment in said hermetic box.

[0031] Thus and according to the invention, the acoustic enclosure includes a physical separation allowing loudspeakers to be compartmentalized and embedded.

[0032] Advantageously and according to the invention, the enclosure comprises a plurality of loudspeakers, including at least one full-range loudspeaker and at least one bass loudspeaker.

[0033] Thus, according to the invention, the acoustic enclosure covers the entire audible spectrum and offers a better sound experience to the listener. Each speaker is therefore specialized and optimized for a specific portion of the frequencies.

[0034] Advantageously and according to the invention, said wideband speaker and said bass speaker are arranged in respective compartments of the internal structure of said airtight enclosure.

[0035] Thus, according to the invention, the enclosure allows for a distinct physical separation of the bass, midrange, and treble frequencies. Separating the frequencies into distinct compartments also helps to avoid distortion and unwanted resonances.

[0036] Advantageously and according to the invention, the distance DI is between 5mm and 30mm.

[0037] Thus and according to the invention, this distance allows the enclosure to keep the vibrating wooden blade at an ideal distance for omnidirectional sound diffusion while allowing a certain freedom of movement to said wooden blade during its vibration.

[0038] Preferably, the distance DI is between 10mm and 15mm. In a preferred embodiment of all, the distance DI is 10mm.

[0039] Indeed, beyond 30mm, there is less sound projection because the vibrating blade is then too far from the enclosure, and this is also problematic for the diffusion of high frequencies. Furthermore, too large a gap between the vibrating blade and the enclosure can cause sound distortion, as the sound could escape too quickly to the sides without being properly redirected by the wooden blade.

[0040] Below 5mm, the DI distance becomes problematic for the presence of the bass speakers whose diaphragm could hit said wooden blade, which would be detrimental to the listening experience, but also to the integrity of the speaker.

[0041] Advantageously and according to the invention, said wooden blade has a perimeter P2 which is higher than the perimeter PI of said lower face so as to have a peripheral overhang with respect to said perimeter PI.

[0042] Thus and according to the invention, this peripheral overhang makes it possible to obtain a longer diffusion plane for all sound waves, which provides a whip effect and a natural amplification of the sound.

[0043] Advantageously and according to the invention, said peripheral overhang has an overhang length LD, representative of the apparent distance between the perimeter P2 of said blade and the perimeter PI of said lower face, LD being between 60mm and 120mm.

[0044] In a preferred embodiment, the overhang length LD is between 70mm and 110mm, preferably between 95mm and 105mm.

[0045] According to this advantageous embodiment, the invention provides a calibrated wooden blade whose dimensions offer a good compromise between blade vibration and its curvature. Indeed, if the overhang length LD is too great, detrimental curvatures could appear. If the overhang length LD is too short, the sound wave would be less amplified and consequently less well diffused at the same operating power.

[0046] Advantageously and according to the invention, the acoustic insulation is a high density textile material.

[0047] Preferably the acoustic insulation comprises a density between 120kg / m3 and 165kg / m3, and even more preferably between 135kg / m3 and 150kg / m3.

[0048] Thus, according to the invention, the high-density acoustic insulation makes it possible to effectively control unwanted reverberations. This type of insulation absorbs sound waves and limits acoustic reflections inside the enclosure.

[0049] Advantageously and according to the invention, the enclosure further comprises a grid arranged opposite said wooden blade.

[0050] Thus and according to the invention, the enclosure benefits from direct protection against projectiles or shocks towards the vibrating blade, which helps to preserve the integrity of the latter, particularly when used in sports facilities such as gymnasiums, or in busy places or industrial environments.

[0051] It is understood that these different examples are given for illustrative purposes only and do not limit the possibilities of use of the invention.

[0052] Preferably, the grid is designed with an open mesh structure or perforated patterns, with an openness ratio greater than 90%, in order to minimize any excessive sound reflection or disturbance of the sound waves emitted by the vibrating blade.

[0053] The grille can be manufactured from robust and durable materials known to those skilled in the art, such as anodized aluminum, stainless steel, carbon fiber composites, or polycarbonate, to ensure high mechanical strength or a lightweight structure suitable for specific environments. The grille can also have an anti-corrosion and anti-scratch finish, ensuring prolonged durability even in demanding environments.

[0054] The grid may also have a flat shape, but also a curved or domed shape to increase its rigidity and limit deformations during an impact.

[0055] Preferably, the grid is arranged opposite the wooden blade at a distance of between 3cm and 10cm, preferably between 5cm and 8cm.

[0056] The said grid can further be fixed by a plurality of attachment points on the casing and can include a damping element to limit parasitic vibrations.

[0057] Advantageously and according to the invention, said wooden blade comprises convex edges.

[0058] Thus, according to the invention, such a wooden blade provides greater durability to said wooden blade, unlike straight edges which are often more fragile. during impacts. In addition, the convex edges help to reduce the risk of injury compared to sharp edges.

[0059] Preferably, the convex edges are designed with a radius of curvature calculated to optimize the distribution of mechanical stresses while maximizing the sound diffusion quality.

[0060] Furthermore, and according to this embodiment of the invention, this geometry promotes uniformity of omnidirectional sound diffusion, reinforcing the whip effect and the fluidity of the waves propagated by the vibrating blade.

[0061] The invention also relates to an acoustic enclosure characterized by all or part of the characteristics mentioned above or below. List of figures

[0062] Other objects, features and advantages of the invention will become apparent from the following description, given by way of non-limiting example only, and which refers to the accompanying figures in which:

[0063] [Fig. 1A] schematically illustrates an overall view of an enclosure according to a first embodiment of the invention

[0064] [Fig.1B] shows an exploded view of an enclosure according to the same embodiment of [Fig.1A]

[0065] [Fig.2] schematically illustrates a detailed view of an elastic support of a enclosure according to an embodiment of the invention

[0066] [Fig.3] schematically illustrates the lower face of the speaker enclosure according to a method of embodiment of the invention

[0067] [Fig.4] schematically illustrates a partitioned box according to another method of implementation of the invention

[0068] [Fig.5] schematically illustrates an enclosure equipped with a grille according to another method of embodiment of the invention

[0069] [Fig. 6A] schematically illustrates a view intended to show the distance DI

[0070] [Fig.6B] schematically illustrates a top view intended to show the length of LD overflow and PI and P2 perimeters

[0071] Detailed description of an embodiment of the invention

[0072] In the figures, the scales and proportions are not strictly respected, for the purposes of illustration and clarity.

[0073] In the entire detailed description that follows with reference to the figures, unless otherwise indicated, each element of the enclosure according to the invention is described as it is arranged during its use.

[0074] Identical, similar or analogous elements are designated by the same references in all figures.

[0075] In the embodiment shown in [Fig.1A] and [Fig.1B], the acoustic enclosure 100 comprises a hermetic parallelepiped box 200, comprising a lower face 210 and an upper face 211 spaced apart according to the height of the other lateral faces of said box 200. The upper face 211 comprises rings 700 configured to receive hangers or a suspension system in order to be able to suspend said acoustic enclosure 100.

[0076] The enclosure 100 also includes a wooden blade 500 fixed and held to said enclosure 200 by means of fastenings comprising elastic supports 600. In the described embodiment, the enclosure 200 and the blade 500 each have four perforations adjoining the four corners of the lower face 210 of the enclosure 200 and the wooden blade 500, respectively. These perforations are visible on the blade 500 [Fig. 1B] and are shown as dotted lines in the enclosure 200 of [Fig. 1A].

[0077] The wooden blade 500 can be made from a single piece of wood or from an assembly of wood sheets compacted by techniques known to a person skilled in the art and has a thickness between 1mm and 7mm and in this embodiment has convex edges on its perimeter P2.

[0078] The positioning of the wooden blade 500 in front of the lower face 210 of the box 200 allows the latter to intercept the waves coming from the loudspeakers directed towards said 500 and to diffuse said waves by vibration in all directions in the plane formed by said blade 500. Said blade 500 then acts as a resonant surface amplifying the sound waves while adding the acoustic softness of the wood.

[0079] The invention presented here introduces a vibrating blade made of tonewood, a material known for its ability to enrich the sound of acoustic instruments. The choice of woods such as poplar, birch, maple, spruce, rosewood, mahogany, walnut, koa, linden, or cedar is based on their acoustic properties. In particular, poplar and birch, selected for their homogeneous density and excellent acoustic conductivity, allow for a sound reproduction that combines warmth, roundness, and precision.

[0080] Fig. 2 shows in detail an elastic support 600 mechanically connecting said hermetic box 200 and said wooden blade 500. These supports have a dual function and allow on the one hand to maintain a distance DI between the lower face 210 of the box 200 and the blade 500, but also to play a role as a damper when the blade 500 vibrates.

[0081] The elastic supports 600 include fastening means comprising a threaded rod 610, a washer 620, and a nut 630. The threaded rod is arranged to pass through the blade 500 and the housing 200. A silent-block type damper 640 includes a threaded hole and dampens vibrations of the blade 500 when the housing 100 is in operation. The diameter of the elastic supports 600 is chosen advantageously according to the size of the 500 blade and the 200 box in order not to alter the diffusion of sound waves.

[0082] Fig. 3 shows an embodiment of the acoustic enclosure 100 in which the enclosure comprises five loudspeakers, including a bass loudspeaker 420 arranged centrally in the box 200 and two pairs of full-range loudspeakers 410 arranged on either side of said bass loudspeaker 420. This figure represents a view of the lower face 210 of the box 200 comprising a particular arrangement of loudspeakers and intended to be arranged opposite a wooden blade 500.

[0083] Fig. 4 illustrates another embodiment of the enclosure 100 comprising three loudspeakers, including a bass loudspeaker 420 and two full-range loudspeakers arranged symmetrically by said loudspeaker 420.

[0084] This figure shows in detail a compartmentalized enclosure 200 comprising two partitions 250 intended to separate the loudspeakers 420 and 410. The partitions 250 are made of MDF fiber panels, the English acronym for "medium density fireboard", known to those skilled in the art.

[0085] Furthermore, according to the invention, the partitioning allows the sound frequencies from two different loudspeakers to be separated and distributed.

[0086] The bass speaker is preferably arranged centrally so that it can carry the high frequencies, which do not travel as far and are less diffused than the low frequencies. This contributes to improving the sound quality of the speakers according to the invention.

[0087] Figure 4 also illustrates the arrangement of the high-density textile material used as acoustic insulation 300. This can be distributed in each compartment on all faces of the box except the lower face 210. The combination of this acoustic insulation 300 with the partitions 250 offers an excellent compromise between rigidity and vibration absorption in order to project the sound almost exclusively towards the blade 500.

[0088] Figure 5 illustrates an embodiment of the invention comprising a grid 800 arranged opposite the blade 500. This grid 800 serves as a protective grid against impacts that could weaken the blade 500, particularly in environments such as gymnasiums or busy places.

[0089] The grid 800 is held on the box 200 by means of fastener 810. In this embodiment the enclosure 100 can be suspended by fasteners 710 arranged on the upper surface 211.

[0090] Fig. 6A shows, purely for illustrative purposes, the distance DI between the lower face 210 of the box 200 and the blade 500. It is understood that this distance DI is assessed when the blade is at rest and not vibrating.

[0091] Fig. B shows, purely for illustrative purposes, the arrangement of the respective contours PI and P2 of the lower face 210 of the box 200 and of the blade 500, which allows the length of the overhang LD to be illustrated.

Claims

Demands

1. Acoustic enclosure (100) characterized in that it comprises: • a hermetically sealed enclosure (200) having at least one lower face (210) and one upper face (211) spaced apart along an axis, referred to as the transverse axis, said lower and upper faces each having a perimeter PI; • an acoustic insulator (300) arranged in said hermetically sealed enclosure; • at least one loudspeaker (400) arranged in said enclosure and oriented to emit a sound wave towards said lower face (210) along a first directed direction, referred to as the initial direction of propagation;• a wooden blade (500) arranged outside said enclosure opposite said lower face (210) and having a perimeter P2 having dimensions greater than or equal to the perimeter PI of said lower face (210), so as to intercept said sound waves traveling along said initial direction of propagation and diffuse them radially in the plane formed by said blade in order to obtain an omnidirectional diffusion of said sound waves by vibration of said blade (500); • at least one elastic support (600) mechanically connecting said airtight enclosure (200) and said wooden blade (500) and configured to maintain at least a distance DI between said airtight enclosure (200) and said blade (500).

2. Enclosure (100) according to claim 1, characterized in that said hermetic box (200) comprises an internal partitioned structure extending between said lower (210) and upper (211) faces so as to define at least one compartment in said hermetic box (200).

3. Enclosure (100) according to any one of the preceding claims, characterized in that it comprises a plurality of loudspeakers of which at least one full-range loudspeaker (410) and at least one bass loudspeaker (420).

4. Enclosure according to claims 2 and 3, characterized in that the wideband speaker (410) and the bass speaker (420) are arranged in respective compartments of the internal structure of said airtight box (200).

5. Enclosure according to any one of the preceding claims, characterized in that the distance DI is between 5mm and 30mm.

6. Enclosure according to any one of the preceding claims, characterized in that said blade (500) has a perimeter P2 greater than the perimeter PI of said lower face (210) so as to have a peripheral overhang with respect to said perimeter PI.

7. Enclosure according to claim 6, characterized in that the peripheral overhang has an overhang length LD, representative of the apparent distance between the perimeter P2 of said blade (500) and the perimeter PI of said lower face (210), LD being between 60mm and 120mm.

8. Enclosure according to any one of the preceding claims, characterized in that the acoustic insulation is a high density textile material.

9. Enclosure according to any one of the preceding claims, characterized in that it further comprises a grid (800) arranged opposite said wooden blade (500).

10. Enclosure according to any one of the preceding claims, characterized in that said wooden blade (500) comprises convex edges.

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