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WO1979000636A1 - Acoustic pressure(or charge)regulator - Google Patents

Acoustic pressure(or charge)regulator Download PDF

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Publication number
WO1979000636A1
WO1979000636A1 PCT/FR1979/000012 FR7900012W WO7900636A1 WO 1979000636 A1 WO1979000636 A1 WO 1979000636A1 FR 7900012 W FR7900012 W FR 7900012W WO 7900636 A1 WO7900636 A1 WO 7900636A1
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WO
WIPO (PCT)
Prior art keywords
filter
pressure
opening
sound
adjustment
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/FR1979/000012
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French (fr)
Inventor
J Thaille
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
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Individual
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Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of WO1979000636A1 publication Critical patent/WO1979000636A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
    • H04R1/2803—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means for loudspeaker transducers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H04R1/26—Spatial arrangements of separate transducers responsive to two or more frequency ranges
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
    • H04R1/2807—Enclosures comprising vibrating or resonating arrangements
    • H04R1/2815—Enclosures comprising vibrating or resonating arrangements of the bass reflex type
    • H04R1/2819—Enclosures comprising vibrating or resonating arrangements of the bass reflex type for loudspeaker transducers

Definitions

  • the present invention relates to a device of the "acoustic pressure (or load) regulator" type which makes it possible to substantially improve the fundamental technical performance of sound transmitters such as the linearity of the amplitude-frequency response curve, the extent of the band bandwidth, harmonic distortion, dynamics, sound image stability and admitted power.
  • acoustic pressure (or load) regulator or load
  • the device according to the present invention makes it possible to avoid these drawbacks by its efficiency, its possibilities and its flexibility of use, its reliability and its low cost price. Indeed, not only does it make it possible to significantly improve the fundamental technical performance (such as linearity of the amplitude-frequency response curve, bandwidth, harmonic distortion, dynamics, stability of the sound image and admitted power) of all transmitters of existing sound including speakers specializing in the midrange and treble, whatever their operating principle and the systems with which they are possibly equipped, but also its development is easy, its manufacture is simple (not requiring very few inexpensive components) and its reliability is high.
  • the fundamental technical performance such as linearity of the amplitude-frequency response curve, bandwidth, harmonic distortion, dynamics, stability of the sound image and admitted power
  • the device object of the present invention comprises a filter 1 (see attached descriptive drawings) mounted on an opening 2 pierced on one of the partitions 3 of the compartment 4 which is directly pressurized by the diaphragm 5 of the loudspeaker. It also includes a system 6 allowing the density of said filter to be adjusted so as to maintain a constant pressure (or charge) 7 determined inside the aforementioned compartment while only allowing the excess to escape. Best way to realize the invention:
  • this filter is made of a porous and elastic material, for example polyether foam. Its isosceles triangle shape having a very sharp acute angle (fig. 2) and its dimensions are adapted to those of the opening on which it is mounted (fig. 3); its surface exceeds on average by 5 mm the edges of the opening, a little more at the base and a little less towards the top (fig. 4). It is held on the opening by bonding which is done on the parts beyond the edges thereof. Depending on the density of the material used, and in order to allow the adjustment of the progressiveness of the latter, the thickness of the filter which is about 20 mm on the side of the base of the triangle, gradually decreases to reach only about 3 mm at its top (fig. 5).
  • the progressiveness of the density of the filter which must be higher on the side of the base of the triangle and progressively lower towards the top, is obtained by compressing this filter by the plate 6 made of rigid material, for example plywood, so that the compression is stronger on the side of the base of the triangle and progressively less towards the top (figs. 6 and 7).
  • the compression force is adjusted by screws 8 and 9.
  • the device which is the subject of the invention therefore makes it possible to obtain an increasing acoustic pressure (or load) of the membranes of the loudspeakers by self-regulation of said pressure (or load).
  • the longitudinal plate 6 can advantageously be replaced by a certain number of small transverse plates 10 (FIG. 8) which can be adjusted separately.
  • the small plates 10 can be replaced by a single molded part 11 (fig. 10) made of plastic for example, which has the same adjustment profile (same elevations) as the prototype which serves as a template for the mold (fig. 11).
  • FIG. 12 shows in dotted line the response curve of a conventional acoustic enclosure equipped with a broadband speaker and in solid line the response curve of the same acoustic enclosure equipped with the pressure regulator (or load) device ) acoustics of the invention.
  • the device which is the subject of the invention can be used in all cases where it is desired to significantly improve the fundamental technical performance of sound transmitters such as: linearity of the amplitude-frequency response curve, bandwidth, harmonic distortion, dynamics, precision and stability of the sound image and admitted power.
  • Particularly interesting applications can be the manufacture of high-quality loudspeakers and the development of specialized speakers in the mid and high registers (tweeter).

Landscapes

  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Circuit For Audible Band Transducer (AREA)

Abstract

Device allowing the improvement of the basic technical performances of sound transmitters, particularly the linearity of the amplitude-frequency response characteristic and the range of the pass-band, by automatic control of their acoustic pressure (or charge), and this on all frequency ranges replayed and at any sound power. It includes a filter (1) (see fig. 1) made of elastic and porous material mounted on the opening (2), of appropriate shape and size, drilled through the wall (3) of the compartment (4) of the sound transmitter which is directly pressurized by the membrane (5) of the loudspeaker. This filter is provided with a system which allows to control the density thereof and thus, to keep the pressure (or charge) (7) constant at a set value, letting only the surplus out. The invention can be applied to the production of improved sound transmitters, such as high quality acoustic units, or high performance loudspeakers specialized in the middle and high register (tweeter).

Description

REGULATEUR DE PRESSION (OU CHARGE) ACOUSTIQUE ACOUSTIC PRESSURE (OR LOAD) REGULATOR

Domaine technicque :Technical area:

La présente inτention concerne un dispositif du type " régulateur de pression (ou charge) acoustique" permettant d'améliorer sensiblement les performances techniques fondamentales des émetteurs de son telles que la linéarité de la courbe de réponse amplitude-fréquence, l'étendue de la bande passante, la distorsion harmonique, la dynamique, la stabilité de l'image sonore et la puissance admise. Technique antérieure :The present invention relates to a device of the "acoustic pressure (or load) regulator" type which makes it possible to substantially improve the fundamental technical performance of sound transmitters such as the linearity of the amplitude-frequency response curve, the extent of the band bandwidth, harmonic distortion, dynamics, sound image stability and admitted power. Prior art:

On a déjà proposé de nombreuses solutions destinées à linéariser la courbe de réponse et à diminuer la distorsion harmonique des enceintes acoustiques sans qu'aucune jusqu'à présent ne se soit montrée totalement satisfaisante.Numerous solutions have already been proposed for linearizing the response curve and reducing the harmonic distortion of the loudspeakers without any having so far shown to be completely satisfactory.

Tous ces systèmes existants, aussi bien mécaniques qu'électroniques, comportent des inconvénients : ils agissent soit uniquement sur la bobine mobile du hautparleur soit sur l'ensemble membrane haut-parleur et enceinte mais leur action se limite en général aux fréquences basses et aucun n'a permis d'améliorer sensiblement les performances des haut-parleurs spécialisés dans le médium et l'aigu.All these existing systems, both mechanical and electronic, have drawbacks: they act either only on the voice coil of the speaker or on the speaker and speaker membrane assembly, but their action is generally limited to low frequencies and no n '' has significantly improved the performance of speakers specializing in midrange and treble.

En plus, certains systèmes, notamment ceux utilisant l'asservissement électronique, sont complexes et ont par conséquent un prix de revient élevé. Exposé de l'invention :In addition, certain systems, in particular those using electronic control, are complex and therefore have a high cost price. Statement of the invention:

Le dispositif suivant la présente invention permet d'éviter ces inconvénients par son efficacité, ses possibilités et sa souplesse d'utilisation, sa fiabilité et son prix de revient modique. En effet, non seulement il rend possible une amélioration sensible des performances techniques fondamentales (telles que linéarité de la courbe de réponse amplitude-fréquence, bande passante, distorsion harmonique, dynamique, stabilité de l'image sonore et puissance admise) de tous les émetteurs de son existants y compris les haut-parleurs spécialisés dans le médium et l'aigu, quels que soient leur principe de fonctionnement et les systèmes dont ils sont éventuellement équipés, mais également sa mise au point est facile, sa fabrication est simple (ne nécessitant que peu de composant de très bon marché) et sa fiabilité est grande. Brève description des dessins :The device according to the present invention makes it possible to avoid these drawbacks by its efficiency, its possibilities and its flexibility of use, its reliability and its low cost price. Indeed, not only does it make it possible to significantly improve the fundamental technical performance (such as linearity of the amplitude-frequency response curve, bandwidth, harmonic distortion, dynamics, stability of the sound image and admitted power) of all transmitters of existing sound including speakers specializing in the midrange and treble, whatever their operating principle and the systems with which they are possibly equipped, but also its development is easy, its manufacture is simple (not requiring very few inexpensive components) and its reliability is high. Brief description of the drawings:

Le dispositif objet de la présente invention, comporte un filtre 1 (voir dessins descriptifs ci-joints) monté sur une ouverture 2 percée sur une des cloisons 3 du compartiment 4 qui est directement mis sous pression par la membrane 5 du haut-parleur. Il comporte également un système 6 permettant de régler la densité du dit filtre de façon à maintenir une pression (ou charge) 7 constante déterminée à l'intérieur du compartiment précité en ne laissant s'échapper que le surplus. Meilleure maniere de réaliser l'invention :The device object of the present invention comprises a filter 1 (see attached descriptive drawings) mounted on an opening 2 pierced on one of the partitions 3 of the compartment 4 which is directly pressurized by the diaphragm 5 of the loudspeaker. It also includes a system 6 allowing the density of said filter to be adjusted so as to maintain a constant pressure (or charge) 7 determined inside the aforementioned compartment while only allowing the excess to escape. Best way to realize the invention:

Selon une réalisation de l'invention, ce filtre est fait d'un matériau poreux et élastique, par exemple en mousse polyéther. Sa forme de triangle isocèle ayant un angle aigu très pointu (fig. 2) et ses dimensions sont adaptées à celles de l'ouverture sur laquelle il est monté (fig. 3); sa surface dépasse en moyenne de 5 mm les bords de l'ouverture, un peu plus à la base et un peu moins vers le sommet (fig. 4). Il est maintenu sur l'ouverture par collage qui se fait sur les parties dépassant les bords de celle-ci. Suivant la densité du matériau utilisé, et en vue de permettre le réglage de la progressivité de celle-ci, l'épaisseur du filtre qui est de 20 mm environ du coté de la base du triangle, diminue progressivement pour n'atteindre qu'environ 3 mm à son sommet (fig. 5). La progressivité de la densité du filtre qui doit être plus forte du coté de la base du triangle et progressivement plus faible vers le sommet, s'obtient en comprimant ce filtre par la plaquette 6 en matériau rigide, par exemple du bois contre-plaqué, de façon à ce que la compression soit plus forte du côté de la base du triangle et progressivement plus faible vers le sommet (fig. 6 et 7). Le réglage de la force de compression se fait par les vis 8 et 9. Une fois le filtre 1 réglé, chacun de ses pores (ou alvéoles) se comportera comme une micro-valve qui s'ouvrira plus ou moins facilement suivant qu'elle est maintenue fermée par une force de compression plus ou moins grande.According to one embodiment of the invention, this filter is made of a porous and elastic material, for example polyether foam. Its isosceles triangle shape having a very sharp acute angle (fig. 2) and its dimensions are adapted to those of the opening on which it is mounted (fig. 3); its surface exceeds on average by 5 mm the edges of the opening, a little more at the base and a little less towards the top (fig. 4). It is held on the opening by bonding which is done on the parts beyond the edges thereof. Depending on the density of the material used, and in order to allow the adjustment of the progressiveness of the latter, the thickness of the filter which is about 20 mm on the side of the base of the triangle, gradually decreases to reach only about 3 mm at its top (fig. 5). The progressiveness of the density of the filter which must be higher on the side of the base of the triangle and progressively lower towards the top, is obtained by compressing this filter by the plate 6 made of rigid material, for example plywood, so that the compression is stronger on the side of the base of the triangle and progressively less towards the top (figs. 6 and 7). The compression force is adjusted by screws 8 and 9. Once the filter 1 is set, each of its pores (or cells) will behave like a micro-valve which will open more or less easily depending on whether it is kept closed by a greater or lesser compressive force.

Ainsi les pores se trouvant du coté du sommet du triangle s'ouvriront le plus facilement, par exemple par la plus faible surpression, parce qu'ils sont les moins comprimés par la plaque 6 alors que ceux qui sont à l'autre extrémité ne s'ouvriront qu'à la surpression maximale.Thus the pores on the side of the top of the triangle will open most easily, for example by the lowest overpressure, because they are the least compressed by the plate 6 while those at the other end are not s 'will open only at maximum overpressure.

Le dispositif, objet de l'invention permet donc d'obtenir une pression (ou charge) acoustique coastante des membranes des haut-parleurs par autorégulation de la dite pression (ou charge).The device which is the subject of the invention therefore makes it possible to obtain an increasing acoustic pressure (or load) of the membranes of the loudspeakers by self-regulation of said pressure (or load).

Pour améliorer la souplesse et la précision des réglages du prototype, on peut avantageusement remplacer la plaquette longitudinale 6 par un certain nombre de petites plaquettes transversales 10 (fig. 8) qui peuvent être réglées séparément.To improve the flexibility and precision of the adjustments to the prototype, the longitudinal plate 6 can advantageously be replaced by a certain number of small transverse plates 10 (FIG. 8) which can be adjusted separately.

Pour simplifier la fabrication en grande série, on peut remplacer les petites plaquettes 10 par une seule pièce moulée 11 (fig. 10) en plastique par exemple, qui possède le même profil de réglage (mêmes dénivellations) que le prototype qui sert de gabarit pour le moule (fig. 11).To simplify mass production, the small plates 10 can be replaced by a single molded part 11 (fig. 10) made of plastic for example, which has the same adjustment profile (same elevations) as the prototype which serves as a template for the mold (fig. 11).

La figure 12 montre en trait pointillé la courbe de réponse d'une enceinte acoustique conventionnelle équipée d'un haut-parleur à large bande passante et en trait plein la courbe de réponse de la même enceinte acoustique équipée du dispositif régulateur de pression (ou charge) acoustique de l'invention. Possibilités d'application industrielle :FIG. 12 shows in dotted line the response curve of a conventional acoustic enclosure equipped with a broadband speaker and in solid line the response curve of the same acoustic enclosure equipped with the pressure regulator (or load) device ) acoustics of the invention. Industrial application possibilities:

Le dispositif, objet de l'invention, peut être utilisé dans tous les cas où on veut améliorer sensiblement les performances techniques fondamentales des émetteurs de son telles que : linéarité de la courbe de réponse amplitude-fréquence, bande passante, distorsion harmonique, dynamique, précision et stabilité de l'image sonore et puissance admise. Des applications particulièrement intéressantes peuvent être la fabrication des enceintes acoustiques de haute qualité et le perfectionnement des haut-parleurs spécialisés dans les registres médium et aigu (tweeter).The device which is the subject of the invention can be used in all cases where it is desired to significantly improve the fundamental technical performance of sound transmitters such as: linearity of the amplitude-frequency response curve, bandwidth, harmonic distortion, dynamics, precision and stability of the sound image and admitted power. Particularly interesting applications can be the manufacture of high-quality loudspeakers and the development of specialized speakers in the mid and high registers (tweeter).

Bien entendu, l'invention n'est pas limitée à l'exemple décrit; de nombreuses modifications peuvent être apportées ou de nombreuses variantes peuvent être réalisées sans sortir pour autant du cadre de la présente invention. Of course, the invention is not limited to the example described; many modifications can be made or many variants can be made without departing from the scope of the present invention.

Claims

REVENDICATIONS 1. - Dispositif permettant d'améliorer sensiblement les performances techniques fondamentales des émetteurs de son par autorégulâtion de leur pression (ou charge) acoustique comprenant un filtre monté sur une ouverture percée sur une des cloisons du compartiment de l'émetteur de son qui est directement mis en pression par la membrane du haut-parleur et un système de réglage. Ce dispositif est caractérisé en ce que le filtre et l'ouverture sur laquelle il est appliqué sont de dimensions adaptées et dépendantes de la surface de la membrane du hautparleur qui créé la pression ainsi que du volume du compartiment dans lequel la pression est créée, et que leur forme est choisie de façon à ce qu'ils comportent une extrémité étroite destinée à l'échappement de la surpression minimale et une extrémité large destinée à l'échappement de la surpression maximale.1. - Device making it possible to appreciably improve the fundamental technical performance of the sound emitters by self-regulation of their acoustic pressure (or load) comprising a filter mounted on an opening pierced on one of the partitions of the sound emitter compartment which is directly pressurized by the speaker diaphragm and an adjustment system. This device is characterized in that the filter and the opening to which it is applied are of suitable dimensions and depend on the surface of the diaphragm of the speaker which creates the pressure as well as on the volume of the compartment in which the pressure is created, and that their shape is chosen so that they have a narrow end intended for escaping the minimum overpressure and a wide end intended for escaping the maximum overpressure. 2. - Dispositif selon la revendication 1, caractérisé en ce que les formes respectives du filtre et de l'ouverture forment un triangle isocèle.2. - Device according to claim 1, characterized in that the respective shapes of the filter and the opening form an isosceles triangle. 3. - Dispositif selon les revendications 1 et3. - Device according to claims 1 and 2 caractérisé en ce que la surface du filtre dépasse de quelques millimètres les bords de l'ouverture sur laquelle il est fixé.2 characterized in that the surface of the filter exceeds by a few millimeters the edges of the opening on which it is fixed. 4. - Dispositif selon l'une quelconque des revendications précédentes, caractérisé en ce que l'épaisseur du filtre n'est pas constante sur toute la surface, celle-ci est plus épaisse du côté de la base du triangle et diminue progressivement en allant vers le sommet. 4. - Device according to any one of the preceding claims, characterized in that the thickness of the filter is not constant over the entire surface, the latter is thicker on the side of the base of the triangle and gradually decreases while going towards the top. 5. - Dispositif selon l'une quelconque des revendications précédentes, caractérisé en ce que le réglage du dit filtre s'effectue en comprimant le filtre par une plaquette en matière rigide à l'aide des vis.5. - Device according to any one of the preceding claims, characterized in that the adjustment of said filter is effected by compressing the filter by a plate of rigid material using screws. 6. - Dispositif selon l'une quelconque des revendications précédentes, caractérisé en ce que le réglage de compression du filtre s'effectue de façon à ce que la compression soit plus forte à la base et progressivement plus faible vers le sommet.6. - Device according to any one of the preceding claims, characterized in that the compression adjustment of the filter is carried out so that the compression is stronger at the base and progressively weaker towards the top. 7. - Dispositif selon la revendication précédente, caractérisé par le fait que le réglage de pression du filtre s'effectue par un certain nombre de plaquettes transversales qui peuvent être réglées séparément.7. - Device according to the preceding claim, characterized in that the filter pressure adjustment is carried out by a number of transverse plates which can be adjusted separately. 8. - Dispositif selon l'une quelconque des revendications précédentes, caractérisé en ce que le système de réglage est fait à l'aide d'une plaquette en plastique moulé qui possède un profil pouvant avoir des dénivellations.8. - Device according to any one of the preceding claims, characterized in that the adjustment system is made using a molded plastic plate which has a profile which can have unevenness. 9. - Dispositif selon l'une quelconque des revendications précédentes, caractérisé en ce que le dit filtre est fait d'un matériau poreux et élastique.9. - Device according to any one of the preceding claims, characterized in that the said filter is made of a porous and elastic material. 10. - Dispositif selon toutes les revendications précédentes, caractérisé en ce que son utilisation n'est pas seulement limitée à la seule fabrication des enceintes acoustiques mais qu'il peut être utilisé également dans d'autres domaines tel que le perfectionnement des haut-parleurs de médium et d'aigu (tweeter) par exemple. 10. - Device according to all the preceding claims, characterized in that its use is not only limited to the sole manufacture of loudspeakers but that it can also be used in other fields such as the improvement of loudspeakers middle and treble (tweeter) for example.
PCT/FR1979/000012 1978-02-17 1979-02-13 Acoustic pressure(or charge)regulator Ceased WO1979000636A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7804505A FR2417909A1 (en) 1978-02-17 1978-02-17 ACOUSTIC PRESSURE (OR CHARGE) REGULATOR
FR7804505 1978-02-17

Publications (1)

Publication Number Publication Date
WO1979000636A1 true WO1979000636A1 (en) 1979-09-06

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ID=9204710

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Application Number Title Priority Date Filing Date
PCT/FR1979/000012 Ceased WO1979000636A1 (en) 1978-02-17 1979-02-13 Acoustic pressure(or charge)regulator

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JP (1) JPS55500096A (en)
FR (1) FR2417909A1 (en)
WO (1) WO1979000636A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995006397A1 (en) * 1993-08-20 1995-03-02 Centralforce Limited Loudspeaker
SG144011A1 (en) * 2006-12-21 2008-07-29 Global Target Entpr Inc Film-type audio output apparatus

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1138781A (en) * 1954-09-03 1957-06-19 Goodmans Ind Ltd Loudspeaker cabinet
FR1533829A (en) * 1966-08-08 1968-07-19 Speaker enclosure
DE1437376A1 (en) * 1963-10-04 1968-10-24 Akg Akustische Kino Geraete Frictional resistance for microphones with changeable directional characteristics and / or changeable frequency response
BE851929A (en) * 1976-04-05 1977-06-16 Ibm PROCESS FOR FORMING AN INTEGRATED CIRCUIT REGION BY THE COMBINATION OF IONIC IMPLEMENTATION AND DIFFUSION STAGES

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE7701417L (en) * 1976-09-27 1978-03-28 Marantz Co SPEAKERS

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1138781A (en) * 1954-09-03 1957-06-19 Goodmans Ind Ltd Loudspeaker cabinet
DE1437376A1 (en) * 1963-10-04 1968-10-24 Akg Akustische Kino Geraete Frictional resistance for microphones with changeable directional characteristics and / or changeable frequency response
FR1533829A (en) * 1966-08-08 1968-07-19 Speaker enclosure
BE851929A (en) * 1976-04-05 1977-06-16 Ibm PROCESS FOR FORMING AN INTEGRATED CIRCUIT REGION BY THE COMBINATION OF IONIC IMPLEMENTATION AND DIFFUSION STAGES

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995006397A1 (en) * 1993-08-20 1995-03-02 Centralforce Limited Loudspeaker
SG144011A1 (en) * 2006-12-21 2008-07-29 Global Target Entpr Inc Film-type audio output apparatus

Also Published As

Publication number Publication date
JPS55500096A (en) 1980-02-21
FR2417909B1 (en) 1983-11-18
FR2417909A1 (en) 1979-09-14

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