FR3107137A1 - Loudspeaker device with increased performance by means of a casing and interior elements covered with an additional flexible gel that absorbs vibrations and pressure variations. - Google Patents

Abstract

Loudspeaker device with increased performance by means of a casing and interior elements covered with a flexible gel that absorbs vibrations and pressure variations. The device according to the invention is composed of a solid box covered with a gel of minimum hardness. The gel absorbs the various vibrations and pressure variations that cannot be absorbed by current acoustic insulation. The mass of the walls and elements of the enclosure is increased without thereby increasing their rigidity. The acoustic enclosure may include conventional acoustic insulators in addition to gel. Many characteristics of the enclosure gel, its shape and its composition can be adapted, the best compromise can be found.

Description

Acoustic enclosure device with increased performance by means of a casing and interior elements covered with an additional flexible gel that absorbs vibrations and pressure variations.

The present invention relates to a loudspeaker device whose internal reverberations as well as the transmission of internal waves to the outside are reduced thanks to the use of a flexible, absorbent and dense additional material.

This type of acoustic enclosure has an internal treatment based on flexible gel which has the effect of reducing internal reverberations, reducing vibrations of the enclosure of the enclosure which radiate into the enclosure and out of the enclosure.

The term “acoustic enclosure” is understood to mean any rigid and at least largely closed system, called a “housing” comprising one or more acoustic transducers. The assembly formed by the rigid casing and the acoustic absorbers is called the “box”.

Current acoustic absorbers are mainly in the form of foam. It is a light absorber which absorbs medium and high frequency waves. The air passing through, it does not filter certain waves towards the speaker box. These waves are thus transmitted to the box, and therefore to the outside and also to the inside of the box precisely because of the vibration of the box. These latter waves as well as the waves reflected inside the box return to the outside through the transducer.

This device makes it possible to limit these 3 modes of disturbance of the signal. The result is a more controlled, crisper sound with no reverb in the midrange, emphasizing the high and low frequencies. The resonances of the subwoofer are also limited, for better signal tracking. Harmonics are negligible.

The device according to the invention is composed of an acoustic enclosure whose walls as well as internal elements are covered with a solid gel absorber, of minimum hardness, and of sufficient density. The resonance frequencies of this material can be adapted thanks to variations in thickness, density and hardness depending on the areas it covers in the enclosure. This adaptation makes it possible to compensate for undesirable resonances in the system that were hitherto uncontrollable using conventional techniques and the allocated budget.

Due to its flexibility and the additional mass it provides, the added material limits the propagation of the waves towards the casing and therefore towards the outside, and also the return of these waves into the enclosure.

1. Partie rigide de l'enceinte acoustique, le boîtier.
2. Gel absorbant.
3. Plaque de renfort permettant d'augmenter la surface de gel d'absorption.

The attached drawing illustrates a possible embodiment of the device. It is composed of the following elements:

1. Rigid part of the loudspeaker, the casing.
2. Absorbent gel.
3. Reinforcement plate to increase the absorption gel surface.

1. Le poids supplémentaire de l'enceinte est flatteur pour qui l'installe ou la manipule.
2. L'utilisation d'un boîtier solide plus épais aurait pour conséquence des résonances toujours présentes, mais à des fréquences plus hautes, donc toujours indésirables. L'enceinte acoustique dotée de ce gel supplémentaire ne modifie pas la rigidité du boîtier
3. Ce poids supplémentaire contribue à la stabilité de l'enceinte
4. Le gel peut recouvrir le bornier de raccordement qui généralement est source de distorsions, ainsi que l'évent d'accord, une partie des transducteurs, tout ou partie du filtre électronique grâce à sa conductivité thermique. Il assure ainsi une homogénéité de garniture interne.
5. L'étanchéité de l'enceinte est améliorée.
6. L'enceinte peut comporter les traitements acoustiques classiques en surface du gel. Ces traitements acoustiques habituels peuvent être fixés au gel directement par incorporation en surface lors de la prise du produit. Ils peuvent aussi être fixés grâce à une colle souple.

Exemple de réalisation d'une enceinte selon le dispositif donné a titre indicatif et non limitatif afin d'illustrer une réalisation possible de l'enceinte acoustique. The realization of an acoustic enclosure according to the device has other advantages:

1. The added weight of the enclosure is flattering to whoever installs or handles it.
2. Using a thicker solid case would result in resonances still present, but at higher frequencies, so still undesirable. The acoustic enclosure with this additional gel does not change the rigidity of the enclosure
3. This additional weight contributes to the stability of the enclosure
4. The gel can cover the connection terminal which is generally a source of distortion, as well as the tuning vent, part of the transducers, all or part of the electronic filter thanks to its thermal conductivity. It thus ensures homogeneity of the internal filling.
5. The tightness of the enclosure is improved.
6. The enclosure may include conventional acoustic treatments on the surface of the gel. These usual acoustic treatments can be fixed to the gel directly by incorporation into the surface when the product sets. They can also be fixed with a flexible glue.

Example of embodiment of an enclosure according to the device given as an indication and not limiting in order to illustrate a possible embodiment of the acoustic enclosure.

In this example, the housing is pre-assembled. The gel is then placed directly in the box on the side faces, as well as the upper and lower faces and on the bottom. On the transducer side, a gel and acoustic foam plate will be glued.

For the other faces other than the face on the transducer side, grids or plates with an attachment profile are glued or screwed onto the internal walls of the enclosure to maintain the gel and perfect cohesion with the case.

The angles and corners are covered with gel, which solidifies in the box, before pouring the gel on the faces. The inclination of the box determines the position of the gel, by gravity, when setting. This is therefore done in several steps.

The faces are then covered one by one with gel which solidifies in the box. The thicknesses on each side of the box are not regular and are progressive thanks to the inclination of the box when the gel takes hold. Conventional acoustic insulation is applied to the surface of the gel before it solidifies, ensuring the hold and the cohesion of the insulation with the gel.

Each pair of opposing planes is not parallel and has different masses so as not to absorb and reflect the same waves. The figure represents an example of 2 opposite faces. The gel (1) Fig.2 is not disposed in equal volume according to the face on which it is disposed, nor is it of the same hardness on the 2 faces. The conventional acoustic insulation (2) Fig.2 is on the surface of this gel. The dimensions (3) Fig.2 and (4) Fig.2 are not identical so as not to absorb nor reverberate common frequencies.

To make the area on the transducer side, acoustic foam is placed at the bottom of a mold taking into account the different desired thicknesses, the areas of the transducers and other appendages not to be treated. The acoustic gel is poured on this foam. We thus obtain a gel plate covered with acoustic foam. The assembly is glued after setting on the box on the transducer side.

End of the example.

Other possible examples of making the enclosure:

The gel parts or plates can be made beforehand before being installed in the box. These pieces or plates of gel are formed beforehand and then glued to the walls and internal elements of the solid part of the acoustic enclosure.

In order to facilitate implementation, the gel can be poured before it solidifies in the casing while the casing is partially pre-assembled.

Another possible embodiment consists in that the acoustic enclosure and its internal elements comprise a gel molded beforehand on the conventional acoustic insulation before being glued to the acoustic enclosure. The mold having the desired relief, the conventional acoustic insulation follows this relief, and therefore the gel cast on the insulation also follows this relief. It is the face of the gel insulation, opposite to the classic acoustic insulation, which will be glued to the box of the acoustic enclosure.

Another possible realization, whether in the case or outside the case for later gluing, the gel is placed in the manner of a 3D printer, before or after assembly of the case. The advantage is to be able to vary the reliefs and also the characteristics of the gel. For example, by adapting the concentration of hardener according to the zones. The acoustic insulation is affixed to the gel by gluing after hardening or during setting by means of a counter-mould. For example, the acoustic enclosure and its internal elements comprise a gel whose relief is produced using a 3D printer which modulates the characteristics of the gel according to the printed areas. A conventional acoustic insulator can be affixed to the gel by gluing after hardening or during the solidification of the gel by means of a counter-mold pressing it against the gel.

Internal air bubbles in the material can be produced during its design or application. The air bubbles can be made in the same material by injecting air, or by injecting previously made flexible air bubbles, in a similar material. Here again, the dimensions of the air bubbles can be controlled and calibrated according to the areas treated and their location in the thickness if the product is poured gradually. The air bubbles may or may not communicate with each other and with the outside of the gel.

Channels can be made in the gel.

A greater elasticity of the gel can be provided by operating the hardening of the gel of the acoustic enclosure while the pressure of air or other surrounding gas, combined or not with the gel, is increased or decreased compared to the usual external pressure, The elastic characteristics of the assembly are thus modified.

The realization of such an enclosure requires various special equipment and materials. Thus, it is possible to offer for sale kits to modify the speakers already produced. These kits include pourable gel, preformed gel pieces, adhesion grids to screw or stick on the internal walls of the enclosure for the maintenance of gel, glue and conventional sound insulation. Filter elements with lugs can also be supplied to maintain the overall balance of the enclosure due to changes in housing characteristics. These are added to existing ones, or replace them, depending on the kit offered. The minimal kit consists of gel pieces and pourable liquid gel. The casting gel also serves as glue for the parts provided.

Claims (11)

Acoustic enclosure device comprising an internal treatment based on flexible gel having the effect of reducing internal reverberations, reducing the vibrations of the enclosure housing which radiate into the enclosure and out of the enclosure. Device according to Claim 1, characterized in that the acoustic enclosure comprises a gel covered with conventional acoustic insulation. Device according to Claim 1, characterized in that the acoustic enclosure comprises pieces or plates of gel formed beforehand and then glued to the walls and internal elements of the solid part of the acoustic enclosure. Device according to Claim 2, characterized in that the acoustic enclosure and its internal elements comprise a gel integrating on its surface conventional acoustic insulation which binds to the gel when the gel solidifies. Device according to one of Claims 1, 3 or 4, characterized in that the acoustic enclosure and its internal elements comprise a cast gel before it solidifies in the case, all or partially pre-assembled. Device according to one of the preceding claims, characterized in that the acoustic enclosure and its internal elements comprise a gel molded beforehand on the conventional acoustic insulation before being glued to the acoustic enclosure, in a mold having the desired relief, the acoustic insulation following this relief, and therefore the gel cast on the insulation also following this relief, it is then the face of the gel insulation, opposite to the conventional acoustic insulation which will be fixed on the enclosure of the enclosure acoustic. Device according to one of Claims 1 to 3, characterized in that the acoustic enclosure and its internal elements comprise a gel whose relief is produced using a 3D printer, also modulating the characteristics of the gel according to the printed areas, with the possibility of affixing a conventional acoustic insulator to the gel by gluing after hardening or when the gel solidifies by means of a counter-mold pressing the insulator onto the gel. Device according to one of Claims 1, 2, 4, 5 and 7, characterized in that grids or plates with an attachment profile are glued or screwed onto the internal walls of the housing of the enclosure to maintain the gel and perfect cohesion. with the box. Device according to one of the preceding claims, characterized in that the environmental conditions of the gel during its hardening are particular: air pressure or other particular surrounding gas, gas or air which can also be combined with the gel, thus modifying the elastic characteristics of the 'together. Device according to one of the preceding claims, characterized in that air bubbles or air or gas channels, whether communicating or not, are integrated into the gel of the acoustic enclosure, the air or gas bubbles being able to be produced by mixing the gel before it solidifies, or by injecting soft air bubbles previously made in a similar material. Kit including the elements necessary for the realization of the device according to one of the preceding claims, characterized in that it comprises parts of gel, and gel to be poured in order to glue the gel parts in order to adapt the device to an already produced loudspeaker.