FR2549333A1 - Passive simulator of infinite load. - Google Patents
Passive simulator of infinite load. Download PDFInfo
- Publication number
- FR2549333A1 FR2549333A1 FR8311663A FR8311663A FR2549333A1 FR 2549333 A1 FR2549333 A1 FR 2549333A1 FR 8311663 A FR8311663 A FR 8311663A FR 8311663 A FR8311663 A FR 8311663A FR 2549333 A1 FR2549333 A1 FR 2549333A1
- Authority
- FR
- France
- Prior art keywords
- membrane
- cabinet
- volume
- replacing
- membranes
- 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.)
- Granted
Links
- 239000012528 membrane Substances 0.000 claims abstract description 23
- 230000006641 stabilisation Effects 0.000 claims abstract 2
- 238000011105 stabilization Methods 0.000 claims 1
- 238000013016 damping Methods 0.000 abstract description 4
- 230000002745 absorbent Effects 0.000 description 4
- 239000002250 absorbent Substances 0.000 description 4
- 230000011514 reflex Effects 0.000 description 4
- 230000006837 decompression Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000009877 rendering Methods 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- 241000238876 Acari Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000005520 electrodynamics Effects 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
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
- H04R1/2869—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself
- H04R1/2884—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself by means of the enclosure structure, i.e. strengthening or shape of the enclosure
- H04R1/2888—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself by means of the enclosure structure, i.e. strengthening or shape of the enclosure 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
- H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
- H04R1/2869—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself
- H04R1/2876—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself by means of damping material, e.g. as cladding
- H04R1/288—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself by means of damping material, e.g. as cladding for loudspeaker transducers
Landscapes
- Health & Medical Sciences (AREA)
- Otolaryngology (AREA)
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Details Of Audible-Bandwidth Transducers (AREA)
Abstract
Description
La présente invention concerne un dispositif pour améliorer la restitution sonore des haut-parleurs par stahilisation de la pression de charge acoustique. The present invention relates to a device for improving the sound reproduction of loudspeakers by stabilizing the acoustic charge pressure.
Si l'on excepte quelques modèles plus expérimentaux que réellement commercialisés (modèles ioniques par exemple) les haut-parleurs émet Lent leur énergie sonore par l'avant ET par l'arrière. Le cas le plus courant est celui du haut-parleur électrodynamique (figure Il, mais quelque soit le principe de propulsion du diaphragme émissif (électrostatique, orthodynamique, etc...) les ondes avant (2) et arrière (3) se trouvent en opposition de phase. If we except a few more experimental models than actually marketed (ionic models for example) the speakers slowly emit their sound energy from the front AND from the rear. The most common case is that of the electrodynamic loudspeaker (Figure II, but whatever the principle of propulsion of the emissive diaphragm (electrostatic, orthodynamic, etc ...) the front (2) and rear (3) waves are in phase opposition.
Grossièrement omnidirectionnelles dans les conditions de propagation courante, ces deux ondes se combinent en une résultante plus faible que chacune des composantes. Pour des raisons tenant à longueur d'onde, ce phénomène parasite est d'autant plus marqué que la fréquence est basse. Aussi le niveau sonore global se trouve-t-il non seulement affaibli, mais encore rendu variable avec la fréquence. Roughly omnidirectional under current propagation conditions, these two waves combine to produce a weaker result than each of the components. For reasons relating to wavelength, this parasitic phenomenon is all the more marked the lower the frequency. The overall sound level is therefore not only weakened, but also made variable with frequency.
Dans leur principe, les remèdes utilisés cherchent tous à séparer, ou au moins éloigner, les ondes avant et arrière. In principle, the remedies used all seek to separate, or at least distance, the front and rear waves.
Le ,baffle plan (figure 2) est un des plus anciens. Il consiste en une plaque rigide (4), percée d'un trou pour monter le haut-parleur
Simple et efficace, ce procédé devient d'un encombrement excessif si on le veut efficace aux basses fréquences.The flat cabinet (Figure 2) is one of the oldest. It consists of a rigid plate (4), pierced with a hole to mount the speaker
Simple and effective, this process becomes excessively bulky if it is to be effective at low frequencies.
Le labyrinthe (figure 3) est une variante du précédent, puisqu'on peut l'assimiler à un baffle plan replié sur lui-même, de façon à réduire l'encombrement extérieur. II est difficile de mise au point (résonances) et coûteux en fabrication. The labyrinth (Figure 3) is a variant of the previous one, since it can be likened to a flat baffle folded back on itself, so as to reduce the external bulk. It is difficult to develop (resonances) and expensive to manufacture.
Le baffle clos (figure 4) consiste en un coffret (4), en principe étanche, rempli d'un absorbant acoustique (matériau fibreux en général) et percé pour monter le(s) haut-parleur(s). Asses efficace et d'un prix raisonnable, c'est la solution la plus répandue, malgré ses inconvénients. En effet, l'absorbant se révèle incapable d'amortir complètement l'onde arrière, et il subsiste l'inconvénient d'une charge variable pour le haut-parleur : le recul de la membrane réduit le volume interne, augmentant d'autant la pression de l'air emprisonné, et inversement. Auditivement, ce freinage pneumatique se traduit par un mauvais rendu des transitoires, principalement dans le registre grave, où les amplitudes sont plus importantes ; sans compter les résonances du coffret, qui doit encaisser la pression sonore interne. The closed baffle (Figure 4) consists of a box (4), in principle waterproof, filled with an acoustic absorbent (fibrous material in general) and pierced to mount the speaker (s). Quite efficient and reasonably priced, it is the most widely used solution, despite its drawbacks. Indeed, the absorbent proves incapable of completely absorbing the rear wave, and there remains the drawback of a variable load for the loudspeaker: the retraction of the membrane reduces the internal volume, thereby increasing the pressure of the trapped air, and vice versa. Auditically, this pneumatic braking results in poor transient rendering, mainly in the low register, where the amplitudes are greater; without counting the resonances of the box, which must absorb the internal sound pressure.
Le bass-reflex (figure 5) est conçu comme un baffle clos, muni d'un évent de décompression (5). On peut le considérer comme un labyrinthe, où l'allongement du trajet de l'onde arrière serait remplacé par son atténuation, au moins partielle. L'exploitation judicieuse de l'onde arrière résiduelle (6) et 1 'élaboration particulière de l'évent (accordé, freiné, etc...) peuvent permettre d'améliorer la réponse dans le grave ; mais 1 'inévitable déphasage entre les ondes (2) et (6) rend la chose difficile et rarement satisfaisante auditivement. D'un prix raisonnable aussi, le bass-reflex est assez répandu. The bass reflex (figure 5) is designed as an enclosed cabinet, fitted with a decompression vent (5). We can consider it as a labyrinth, where the lengthening of the path of the rear wave would be replaced by its attenuation, at least partial. The judicious use of the residual rear wave (6) and one particular development of the vent (tuned, braked, etc.) can improve the response in the bass; but the inevitable phase difference between the waves (2) and (6) makes it difficult and rarely satisfying hearing. Also reasonably priced, bass reflex is quite widespread.
Un haut-parleur passif (5) (voir figure 6), c'est à dire sans alimentation électrique, peut éventuellement remplacer l'évent d'un bass-reflex. A passive speaker (5) (see Figure 6), that is to say without power supply, can possibly replace the vent of a bass-reflex.
Le simulateur actif de charge infinie est un baffle clos dont le volume interne est maintenu constant (figure 7) : le diaphragme d'un haut-parleur auxiliaire (5), excité électriquement, se déplace en concordance avec celui du haut-parleur principal, de façon à maintenir constant le volume (7) qui charge ce dernier. Un compartiment auxiliaire (8), étanche et très absorbant, est nécessaire pour amortir 1 'onde (6) émise par le "côté non utilisé" du haut-parleur secondaire. The active infinite load simulator is a closed cabinet whose internal volume is kept constant (Figure 7): the diaphragm of an auxiliary loudspeaker (5), electrically excited, moves in concordance with that of the main loudspeaker, so as to keep constant the volume (7) which charges the latter. An auxiliary compartment (8), waterproof and very absorbent, is necessary to absorb the wave (6) emitted by the "unused side" of the secondary speaker.
Par principe même, cette solution donne d'excellents résultats, mais elle est très onéreuse, car elle conduit à doubler le nombre des composants.In principle, this solution gives excellent results, but it is very expensive because it leads to doubling the number of components.
Le dispositif selon l'invention permet de remédier à cet inconvénient. Dans une forme de réalisation préférentielle (fiv. 8), le baffleà simulateur passif de charge infinie s'apparente à un baffle clos dont une face est remplacée par une membrane (9). Cette dernière est choisie ou réalisée pour présenter les caractéristiques adéquates d'amortissement interne, d'élasticité, de masse spécifique, d'absorption et réflexion acoustiques, etc... Le compromis nécessaire entre ces différentes qualités relève de l'art de l'ingénieur, de meme que le choix de la ou des face(s) et de la proportion (tout ou partie) membranées. The device according to the invention overcomes this drawback. In a preferred embodiment (fiv. 8), the passive infinity load simulator cabinet resembles a closed cabinet whose face is replaced by a membrane (9). The latter is chosen or produced to present the adequate characteristics of internal damping, elasticity, specific mass, acoustic absorption and reflection, etc. The necessary compromise between these different qualities is a matter of the art of engineer, as well as the choice of the face (s) and the proportion (all or part) membrane.
Les rôles principaux de cette membrane sont les suivants - par ses caractéristiques de surface, elle peut participer a l'amor-
tissement des fréquences aigues dans le volume de charge, - par sa qualité de membrane, elle participe, dans le volume de charge,
à l'amortissement des fréquences graves. Dans ce rôle, les membranes
sont en effet beaucoup plus efficaces que les absorbants classiques
(fibreux ou poreux) mieux adaptés aux fréquences plus élevées, - par ses caractéristiques d'élasticité, elle contribue à maintenir
constant le volume de charge : toute surpression (ou dépression'
interne entraine, ipso facto, une déformation concordante de la
membrane.Ce fonctionnement s'oppose à celui d'un haut-parleur passif
en ce sens que l'onde sonore réémise est volontairement rendue
négligeable par les caractéristiques d'amortissement interne de 1.7
membrane.The main roles of this membrane are as follows - by its surface characteristics, it can participate in the absorption-
waning of the acute frequencies in the volume of load, - by its quality of membrane, it participates, in the volume of load,
damping of low frequencies. In this role, the membranes
are indeed much more effective than conventional absorbents
(fibrous or porous) better suited to higher frequencies, - by its elasticity characteristics, it helps maintain
constant charge volume: any overpressure (or depression)
internal causes, ipso facto, a concordant deformation of the
membrane.This operation is opposed to that of a passive speaker.
in the sense that the re-emitted sound wave is voluntarily rendered
negligible by the internal damping characteristics of 1.7
membrane.
Les réalisations ne sont naturellement pas limitées au cas de ln figure 8. La figure 9 représente une version plus commerciale, où le volume secondaire (8) et l'orifice de décompression (5) peuvent Entre optimisés en vue du meilleur résultat. Dans le cas de la figure 10, la membrane sert en meme temps de joint souple pour le montage du ou des haut-parleur(s). The embodiments are naturally not limited to the case of FIG. 8. FIG. 9 represents a more commercial version, where the secondary volume (8) and the decompression orifice (5) can be optimized for the best result. In the case of Figure 10, the membrane serves at the same time as a flexible seal for mounting the speaker (s).
Les figures 10 à 15 représentent des exemples d'utilisation en bass-reflex, la membrane pouvant ou non etre pourvue de son propre évent (5 bis). L'augmentation du nombre de paramètres ainsi obtenue permet de mieux maîtriser la mise au point de ce type de baffle. Figures 10 to 15 show examples of use in bass reflex, the membrane may or may not be provided with its own vent (5a). The increase in the number of parameters thus obtained allows better control of the development of this type of cabinet.
Les figures 16 et 17 représentent, parmi les multiples combinaisons possibles, deux exemples d'utilisation en baffle à volumes multiples, déterminés, ainsi que les membranes, pour optimiser les résultats. Enfin, l'utilisation du dispositif ne se limite pas aux haut-parleurs de grave, mais peut etre envisagée avec succès avec les haut-parleurs de médium, et, dans une moindre mesure, avec les hautparleurs d'aigu. Figures 16 and 17 represent, among the multiple possible combinations, two examples of use in a cabinet with multiple volumes, determined, as well as the membranes, to optimize the results. Finally, the use of the device is not limited to woofers, but can be successfully considered with mid-range speakers, and, to a lesser extent, with tweeter.
Les avantages de ce dispositif sont nombreux : - séparation des ondes avant et arrière supérieure à celle des baffles
classiques, - atténuation efficace des résonances de coffret (c'est la membrane
qui encaisse ses surpressions).The advantages of this device are numerous: - separation of the front and rear waves greater than that of the baffles
classics, - effective attenuation of cabinet resonances (this is the membrane
which collects its overpressures).
- excellent rendu des transitoires, graAce à la constance du volume
de charge, - réduction plus aisée du volume de charge, donc de 1 'encombrement
du coffret, - autolimitation possible des amplitudes dangereuses pour le haut
parleur, par adaptation de la tension de la membrane, - mise au point facilitée : elle dépend essentiellement des caractéris
tiques de la membrane, - simplicité de construction, - faible. prix de revient : on peut fabriquer à bon marché les matériaux
membraneux adaptés, - bonne reproductibilité, - universalité d'emploi : en conservant tout ou partie de ses qualités,
ce procédé peut être utilisé avec tous les hafflages existants
plan, labyrinthe, reflex, clos, etc... - excellent transient rendering, thanks to the constant volume
load, - easier reduction of the load volume, therefore 1 'congestion
of the cabinet, - possible self-limitation of dangerous amplitudes for the top
speaker, by adaptation of the membrane tension, - easier tuning: it essentially depends on the characteristics
membrane ticks, - simplicity of construction, - low. cost price: materials can be made cheaply
membranous adapted, - good reproducibility, - universality of use: by preserving all or part of its qualities,
this process can be used with all existing hafflages
plan, labyrinth, reflex, closed, etc ...
Le dispositif selon l'invention est plus particulièrement destiné à la reproduction sonore de haute qualité. The device according to the invention is more particularly intended for high quality sound reproduction.
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8311663A FR2549333B1 (en) | 1983-07-13 | 1983-07-13 | PASSIVE INFINITE LOAD SIMULATOR |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8311663A FR2549333B1 (en) | 1983-07-13 | 1983-07-13 | PASSIVE INFINITE LOAD SIMULATOR |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| FR2549333A1 true FR2549333A1 (en) | 1985-01-18 |
| FR2549333B1 FR2549333B1 (en) | 1987-01-02 |
Family
ID=9290785
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| FR8311663A Expired FR2549333B1 (en) | 1983-07-13 | 1983-07-13 | PASSIVE INFINITE LOAD SIMULATOR |
Country Status (1)
| Country | Link |
|---|---|
| FR (1) | FR2549333B1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000070908A2 (en) * | 1999-05-14 | 2000-11-23 | New Transducers Limited | Bending wave loudspeakers |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2991840A (en) * | 1957-09-12 | 1961-07-11 | Glenn C Van Camp | Sound reproducer |
| GB903995A (en) * | 1957-09-10 | 1962-08-22 | Philips Electrical Ind Ltd | Improvements in or relating to loudspeaker enclosures |
| US3554313A (en) * | 1968-11-20 | 1971-01-12 | Richard Owen Young | Loudspeaker systems |
| US3667568A (en) * | 1970-09-15 | 1972-06-06 | Arthur Liebscher | Pressure compensator for speaker cabinets |
-
1983
- 1983-07-13 FR FR8311663A patent/FR2549333B1/en not_active Expired
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB903995A (en) * | 1957-09-10 | 1962-08-22 | Philips Electrical Ind Ltd | Improvements in or relating to loudspeaker enclosures |
| US2991840A (en) * | 1957-09-12 | 1961-07-11 | Glenn C Van Camp | Sound reproducer |
| US3554313A (en) * | 1968-11-20 | 1971-01-12 | Richard Owen Young | Loudspeaker systems |
| US3667568A (en) * | 1970-09-15 | 1972-06-06 | Arthur Liebscher | Pressure compensator for speaker cabinets |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000070908A2 (en) * | 1999-05-14 | 2000-11-23 | New Transducers Limited | Bending wave loudspeakers |
| WO2000070908A3 (en) * | 1999-05-14 | 2001-02-15 | New Transducers Ltd | Bending wave loudspeakers |
| US6397972B1 (en) | 1999-05-14 | 2002-06-04 | New Transducers Limited | Loudspeakers |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2549333B1 (en) | 1987-01-02 |
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| Date | Code | Title | Description |
|---|---|---|---|
| ST | Notification of lapse |