EP3225038B1 - Absorbeur acoustique actif basse fréquence par commande de la vitesse acoustique à travers des couches résistives poreuses - Google Patents

Absorbeur acoustique actif basse fréquence par commande de la vitesse acoustique à travers des couches résistives poreuses Download PDF

Info

Publication number
EP3225038B1
EP3225038B1 EP15810768.0A EP15810768A EP3225038B1 EP 3225038 B1 EP3225038 B1 EP 3225038B1 EP 15810768 A EP15810768 A EP 15810768A EP 3225038 B1 EP3225038 B1 EP 3225038B1
Authority
EP
European Patent Office
Prior art keywords
acoustic
fabric
microphone
gain
preamplifier
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.)
Active
Application number
EP15810768.0A
Other languages
German (de)
English (en)
Other versions
EP3225038A1 (fr
Inventor
Alain Roux
Christian Martin
Antoine PITTET
David STROBINO
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.)
Relec SA
Original Assignee
Relec SA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Relec SA filed Critical Relec SA
Publication of EP3225038A1 publication Critical patent/EP3225038A1/fr
Application granted granted Critical
Publication of EP3225038B1 publication Critical patent/EP3225038B1/fr
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/002—Damping circuit arrangements for transducers, e.g. motional feedback circuits
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17857—Geometric disposition, e.g. placement of microphones
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17861—Methods, e.g. algorithms; Devices using additional means for damping sound, e.g. using sound absorbing panels
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1787—General system configurations
    • G10K11/17879—General system configurations using both a reference signal and an error signal
    • G10K11/17881—General system configurations using both a reference signal and an error signal the reference signal being an acoustic signal, e.g. recorded with a microphone
    • 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
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/10—Applications
    • G10K2210/12—Rooms, e.g. ANC inside a room, office, concert hall or automobile cabin
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/301—Computational
    • G10K2210/3026—Feedback
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/301—Computational
    • G10K2210/3027—Feedforward
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G10K2210/3212—Actuator details, e.g. composition or microstructure
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R29/00—Monitoring arrangements; Testing arrangements
    • H04R29/001—Monitoring arrangements; Testing arrangements for loudspeakers

Definitions

  • the invention relates to acoustic absorbers.
  • an equalizing system compensates the signal transmitted to the loudspeaker by reducing the frequencies that resonate in a particular room with particular equipment, furniture and people inside it.
  • a main problem with this system is that it alters the primary sound emitted by the loudspeaker thus reducing the fidelity of the source-this is not acceptable to some users.
  • a second problem is that the equalizing is not adaptive and the setup process must be done each time the room specifics change, e.g. if an extra person enters the room.
  • the passive bass-trap comprises a resonating membrane in front of a damping material or air volume with a size tuned to the frequency that needs to be absorbed-typically 20-100 Hz.
  • the system needs to have large dimensions and is dedicated to a single frequency when typically several frequencies need to be treated and these several frequencies vary according to the specificities of the room.
  • the large amount of absorbing equipment needed also increases the cost as well as significantly reduces the volume of the room.
  • This system comprises a microphone that controls a loudspeaker to absorb specific low frequencies.
  • An advantage of this system is that the footprint is smaller than with a passive bass-trap.
  • a main limitation to this system is that it needs to be adjusted to a specific frequency and therefore is also dependent on the room specificities. It must therefore be set up using precise sound measurements and adjusted each time the room specificities change, e.g., if a person enters the room.
  • An active acoustic impedance system comprises a loudspeaker in a closed cabinet connected to a feedback control loop based on a combination of pressure measured with a microphone and the velocity of the loudspeaker's membrane, acquired through an impedance bridge-motional feedback principle patented by Philips.
  • Electroacoustic absorber (international publication WO 2014 / 053994 A1 to H. Lissek, R. Boumét and E. Rivet)
  • An active impedance control system comprises a loudspeaker in a closed cabinet and connected to a specific electric impedance synthetized and made up of a combination of digital electric filter in a digital processor associated to a transconductance amplifier and a setup of analog components.
  • the invention provides an electroacoustic device for wide band low frequency absorption.
  • the device comprises at least one electroacoustic transducer, mounted on an acoustic baffle, separating a closed rear volume and a front volume, the front volume being closed by an acoustic fabric of determined acoustic air-flow resistance; a power amplification electronic with membrane velocity feedback control, configured to obtain a transducer membrane velocity proportional to an input voltage, coming from a microphone located in front of the acoustic fabric on a side opposite from the front volume, connected to a microphone preamplifier; and a feedforward control, with adjustable gain and band-pass filter, taking a first pressure signal coming from the microphone preamplifier and driving the power amplifier input, the feedforward control gain being equal to A f 1 R ⁇ A l s G 1 where A f is the fabric area, A ls the projected transducer membrane area, R the fabric air-flow resistance and G 1 the preamplifier gain, minimizing the acous
  • the membrane velocity feedback control is based on an impedance bridge.
  • the electroacoustic device further comprises an additional microphone located behind the acoustic fabric in the front volume, with an additional microphone preamplifier; and a feedback control loop, with adjustable gain and band-pass filter, taking a second pressure signal coming from the additional microphone preamplifier, the signals coming from the feedforward control and the membrane velocity feedback control being added to drive the power amplifier input, the feedforward control gain being equal to A f R ⁇ A l s ⁇ 1 G 1 and the feedback control gain being equal to a significantly larger value than the feedforward control gain, minimizing the acoustic pressure in the front volume, thus having the specific impedance in front of the acoustic fabric equal to the specific air-flow resistance of the fabric.
  • the membrane velocity feedback control is realized using an integrator circuit, configured to integrate over time a signal coming from an accelerometer located on the transducer membrane.
  • the membrane velocity feedback control is realized using a differentiator circuit, configured to differentiate over time a signal coming from an additional microphone preamplifier, with an additional microphone located in the closed rear volume and connected to the additional microphone preamplifier.
  • the electroacoustic transducer is equipped with two coils, one of which is connected to the output of the power amplification electronic and the other of which produces an induced voltage representative of a velocity measurement, the induced voltage being proportional to the transducer membrane velocity and output as membrane velocity feedback control to the power amplification electronic.
  • the electroacoustic device further comprises at least one additional acoustic fabric layer in front of the acoustic fabric, whereby the first microphone is located between the two acoustic fabric layers.
  • the present invention generally concerns an active low-frequency acoustic absorber system which has a relatively small footprint compared to systems from prior art, is auto-adaptive and avoids any altering of the sound source.
  • the invention allows controlling modal acoustic resonances in closed areas by using one or more absorbers and avoiding any initial setup.
  • the invention further allows doing away with any adjustment in case the room specifics are changed, such as moving people or furniture.
  • the bandwidth of action is also much larger than in any other system from prior art.
  • the realization of a low frequency passive absorption system with low acoustic impedance involves physical dimensions around a quarter of the wavelength.
  • the inventive device is much smaller in volume and footprint, and is a mobile asset.
  • the footprint and lateral area of the absorber box are small compared to the area of the walls of the room.
  • the invention is built starting from a layer of porous acoustic fabric of given flow resistance. As the layer is thin, the flow resistance is essentially resistive, i.e. with negligible reactive part.
  • the invention uses a predictive setpoint (feedforward control).
  • a f the fabric area.
  • This volume flow rate q is realized with a velocity transducer. At low frequencies, the physical dimensions of the device are significantly smaller than the wavelength.
  • the absorption area is significantly increased by this method, as A f can be easily ten times bigger than A ls .
  • a feedback control loop using the internal pressure p int .
  • the pressure p int is equivalent to an error signal that can be used directly: a positive internal pressure has to produce a positive transducer velocity, according to Fig. 1 .
  • Fig. 2 shows a schematic of a preferred embodiment of the invention, starting with a resistive acoustic fabric (5). These fabrics are manufactured with precise and well-known characteristics and with flow resistance lower than Z c .
  • the acoustic fabric is a synthetic weaved mesh with an air-flow resistance of 100 Pa ⁇ s/m-an optimal value to efficiently absorb modal resonances in the range 10-200 Hz for a room of 40-60 m 3 .
  • the air-flow resistance is essentially resistive, i.e. with negligible reactive part at low frequencies.
  • the acoustic fabric (5) forms the front side of a closed volume (4), of which the back side is a baffle (2) including one or more velocity transducers (1).
  • the transducers are then mounted on a closed rear volume (3).
  • the feedforward control (10) also includes a band-pass filter to control the bandwidth of the system and guarantee its stability.
  • the power amplifier (6) uses a measurement (7) of the transducer (1) membrane velocity in a feedback loop in order that the membrane velocity matches the input signal of the amplifier.
  • the velocity transducer-consisting of the transducer (1), the power amplifier (6) and the velocity measurement (7)- is based on an impedance bridge shown in Fig. 3 , where the input voltage V in is the power amplifier input.
  • V l s Z l s ⁇ I + B l ⁇ v l s
  • I the current through the loudspeaker coil
  • Bl the force factor
  • v ls the membrane velocity.
  • Resistor R 0 is chosen small in order to save power.
  • Resistors R 1 and R 2 are proportional to R 0 and R e respectively.
  • This bridge can also be realized without the inductor L 0 .
  • complex impedances Z 1 and Z 2 shall be used in place of resistors R 1 and R 2 respectively. This is also true when a more accurate loudspeaker model is used for Z is , e.g. to account for eddy currents, according to [3]. In practical applications, the accuracy of this model will determine the bandwidth of the system.
  • the velocity measurement (7) can be realized with an accelerometer ( Fig. 5 ), a microphone in the closed rear volume ( Fig. 6 ) or a dual coil loudspeaker ( Fig. 7 ).
  • the membrane (1) acceleration is acquired by means of an accelerometer (14) located on the loudspeaker (1) membrane. This acceleration signal is then integrated over time in an integrator circuit (15) to get the proper velocity signal to drive the power amplifier (6) feedback input.
  • the membrane (1) displacement is acquired by means of an additional microphone (16) located inside the closed rear volume (3) with the help of an additional preamplifier (17).
  • the microphone gets the pressure inside the closed volume, which is proportional to the membrane displacement.
  • a derivative circuit (18) takes the derivative over time of this displacement signal, which is used to drive the power amplifier (6) feedback input.
  • the loudspeaker (1) is equipped with two coils, one of which is connected to the output of the amplifier (6) and the other of which produces an induced voltage that is used as a velocity measurement (7).
  • This velocity voltage is proportional to the membrane velocity and is used to drive the power amplifier (6) feedback input.
  • a particular embodiment of the invention shown in Fig. 4 includes an additional microphone (11) located behind the acoustic fabric (5), on a side opposite to the first microphone (8), an additional preamplifier (12) and a feedback control (13).
  • the second microphone delivers an error signal, which is used in a feedback loop.
  • the invention of the preferred embodiment further comprises an additional acoustic fabric (19) of air-flow resistance R ' in front of the first one, on a side opposite to the transducer (1).
  • the acoustic pressure between the two fabrics (5) and (19) is acquired by the first microphone (8).
  • the feedforward control (10) takes the microphone pressure signal and drives the power amplifier input (6), including the transfer function H 1 and the band-pass filter.
  • the invention of a last embodiment shown in Fig. 9 further comprises an additional microphone (20) in front of the additional acoustic fabric (19), on a side opposite to the transducer (1), an additional microphone preamplifier (21) and an additional feedforward control (22), including a band-pass filter, which takes the second preamplifier (21) output signal and drives the power amplifier input (6) in addition to the first feedforward control (10).
  • H 3 ⁇ 1 ⁇ A f R ⁇ A l s ⁇ 1 G 1
  • the invention may advantageously be used to build an adaptive acoustic absorber, compact and mobile, destined to be used in single or several units in rooms typically the size of cabin studios up to large recording studios.
  • inventive technology may also advantageously be put to use to achieve small dimension anechoic chambers as well as laboratory measurement of acoustic impedance on surfaces.
  • the invention provides a target acoustic impedance lower than the characteristic impedance of the medium (air); works on a broad bandwidth; and provides a large active absorption area, significantly larger than the area of the transducers used.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Circuit For Audible Band Transducer (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)

Claims (8)

  1. Dispositif électroacoustique pour absorption basse fréquence à large bande, le dispositif comprenant :
    au moins un transducteur électroacoustique (1), monté sur un écran acoustique (2), séparant un volume arrière fermé (3) et un volume avant (4), le volume avant étant fermé par un tissu acoustique (5) de résistance acoustique à l'écoulement de l'air prédéterminée ;
    un amplificateur de puissance (6) avec un asservissement de vitesse de membrane (7), configuré pour obtenir une vitesse de membrane de transducteur proportionnelle à une tension d'entrée, ladite tension provenant d'un microphone (8) situé devant le tissu acoustique (5) sur un côté opposé au volume avant (4), relié à un préamplificateur de microphone (9) ;
    une commande prédictive (10), avec gain réglable et filtre passe-bande, prenant un premier signal de pression provenant du préamplificateur de microphone (9) et commandant l'entrée de l'amplificateur de puissance (6), le gain de la commande prédictive étant égal A f R ⋅ A ls ⋅ 1 G 1
    Figure imgb0030
     où Af est la surface du tissu (5), Als la surface projetée de la membrane du transducteur (1), R la résistance à l'écoulement de l'air du tissu et G1 le gain du préamplificateur (9), minimisant la pression acoustique dans le volume avant (4), ayant ainsi une impédance spécifique, définie comme le rapport pression/vitesse, devant le tissu acoustique égale à la résistance à l'écoulement de l'air déterminée du tissu acoustique.
  2. Dispositif électroacoustique de la revendication 1, dans lequel l'asservissement de vitesse de membrane (7) est basé sur un pont d'impédance.
  3. Dispositif électroacoustique de la revendication 1, comprenant en outre :
    un microphone supplémentaire (11) situé derrière le tissu acoustique (5) dans le volume avant (4), avec un préamplificateur de microphone supplémentaire (12) ;
    une boucle d'asservissement (13), avec gain réglable et filtre passe-bande, prenant un deuxième signal de pression provenant du préamplificateur de microphone supplémentaire (12), les signaux provenant de la commande prédictive (10) et de l'asservissement (13) étant ajoutés pour commander l'entrée de l'amplificateur de puissance (6), le gain de la commande prédictive étant égal à A f R ⋅ A ls ⋅ 1 G 1
    Figure imgb0031
     et le gain de l'asservissement étant égal à une valeur sensiblement supérieure au gain de la commande prédictive, minimisant la pression acoustique dans le volume avant (4), ayant ainsi l'impédance spécifique devant le tissu acoustique égale à la résistance à l'écoulement de l'air spécifique du tissu.
  4. Dispositif électroacoustique de la revendication 1, dans lequel l'asservissement de vitesse de membrane (7) est réalisé en utilisant
    un circuit intégrateur (15), configuré pour intégrer dans le temps un signal provenant
    d'un accéléromètre (14) situé sur la membrane du transducteur (1).
  5. Dispositif électroacoustique de la revendication 1, dans lequel l'asservissement de vitesse de membrane (7) est réalisé en utilisant
    un circuit différenciateur (18), configuré pour différencier dans le temps un signal provenant
    d'un préamplificateur de microphone supplémentaire (17), avec un microphone supplémentaire (16) situé dans le volume arrière fermé (3) et relié au préamplificateur de microphone supplémentaire.
  6. Dispositif électroacoustique de la revendication 1, dans lequel le transducteur électroacoustique (1) est équipé de deux bobines, dont une est reliée à la sortie de l'amplificateur de puissance (6) et l'autre produit une tension induite représentative d'une mesure de vitesse, la tension induite étant proportionnelle à la vitesse de membrane du transducteur (1) et délivrée en tant qu'asservissement de vitesse de membrane (7) à l'amplificateur de puissance (6).
  7. Dispositif électroacoustique de la revendication 1, comprenant en outre au moins une couche de tissu acoustique supplémentaire (19) devant le tissu acoustique (5), le premier microphone (8) étant ainsi situé entre les deux couches de tissu acoustique (5 et 19) .
  8. Dispositif électroacoustique de la revendication 7, comprenant en outre au moins un microphone supplémentaire (20) devant un deuxième tissu acoustique (19), sur un côté opposé au premier microphone (8), avec son préamplificateur de microphone (21) et une commande prédictive avec gain réglable et filtre passe-bande (22), le signal provenant des deux commandes prédictives étant combiné linéairement pour commander l'entrée de l'amplificateur de puissance (6), le gain de la première commande prédictive étant égal à ρ 1 ⋅ A f R ⋅ A ls ⋅ 1 G 1
    Figure imgb0032
     et le gain de la deuxième commande prédictive étant égal à ρ 2 ⋅ A f R + R ' ⋅ A ls ⋅ 1 G 2
    Figure imgb0033
     où G 2 est le gain du deuxième préamplificateur (21) et ρ 1 et ρ 2 sont des coefficients de pondération liés par ρ1 + ρ 2 = 1, minimisant la pression acoustique dans le volume avant (4), ayant ainsi l'impédance spécifique devant le tissu acoustique égale à la somme des résistances à l'écoulement de l'air spécifiques des tissus.
EP15810768.0A 2014-11-28 2015-11-23 Absorbeur acoustique actif basse fréquence par commande de la vitesse acoustique à travers des couches résistives poreuses Active EP3225038B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB1421213.8A GB2532796A (en) 2014-11-28 2014-11-28 Low frequency active acoustic absorber by acoustic velocity control through porous resistive layers
PCT/IB2015/059029 WO2016083971A1 (fr) 2014-11-28 2015-11-23 Absorbeur acoustique actif basse fréquence par commande de la vitesse acoustique à travers des couches résistives poreuses

Publications (2)

Publication Number Publication Date
EP3225038A1 EP3225038A1 (fr) 2017-10-04
EP3225038B1 true EP3225038B1 (fr) 2018-09-05

Family

ID=52349656

Family Applications (1)

Application Number Title Priority Date Filing Date
EP15810768.0A Active EP3225038B1 (fr) 2014-11-28 2015-11-23 Absorbeur acoustique actif basse fréquence par commande de la vitesse acoustique à travers des couches résistives poreuses

Country Status (3)

Country Link
EP (1) EP3225038B1 (fr)
GB (1) GB2532796A (fr)
WO (1) WO2016083971A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018164438A1 (fr) * 2017-03-10 2018-09-13 Samsung Electronics Co., Ltd. Procédé et appareil d'optimisation de puissance sonore basse fréquence dans une pièce
US10469046B2 (en) * 2017-03-10 2019-11-05 Samsung Electronics Co., Ltd. Auto-equalization, in-room low-frequency sound power optimization
FR3104860B1 (fr) * 2019-12-16 2024-05-17 Centre Nat Rech Scient Procede et dispositif de controle de la propagation des ondes acoustiques sur une paroi
US11626094B2 (en) 2020-03-03 2023-04-11 Toyota Motor Engineering & Manufacturing, Inc. Membrane acoustic absorber

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4027511C1 (fr) * 1990-08-30 1991-10-02 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V., 8000 Muenchen, De
CH685657A5 (de) * 1992-03-24 1995-08-31 Maximilian Hobelsberger Vorrichtung zur aktiven Simulation einer akustischen Impedanz.
FR2778741B1 (fr) * 1998-05-12 2001-04-27 Ct Scient Tech Batiment Cstb Dispositif de controle actif d'impedance acoustique
US6778673B1 (en) * 1998-10-28 2004-08-17 Maximilian Hans Hobelsberger Tunable active sound absorbers
US7190796B1 (en) * 2000-11-06 2007-03-13 Design, Imaging & Control, Inc. Active feedback-controlled bass coloration abatement
US7970148B1 (en) * 2007-05-31 2011-06-28 Raytheon Company Simultaneous enhancement of transmission loss and absorption coefficient using activated cavities
CN103559877A (zh) * 2013-07-17 2014-02-05 南京大学 一种基于分流扬声器和微穿孔板的复合吸声结构

Also Published As

Publication number Publication date
EP3225038A1 (fr) 2017-10-04
GB201421213D0 (en) 2015-01-14
GB2532796A (en) 2016-06-01
WO2016083971A1 (fr) 2016-06-02

Similar Documents

Publication Publication Date Title
US9961464B2 (en) Pressure gradient microphone for measuring an acoustic characteristic of a loudspeaker
Rivet et al. Broadband low-frequency electroacoustic absorbers through hybrid sensor-/shunt-based impedance control
EP3225038B1 (fr) Absorbeur acoustique actif basse fréquence par commande de la vitesse acoustique à travers des couches résistives poreuses
US4783817A (en) Electronic noise attenuation system
US8428284B2 (en) Loudspeaker with passive low frequency directional control
US9743181B2 (en) Loudspeaker equalizer
US11166100B2 (en) Bass optimization for audio systems and devices
EP2941012B1 (fr) Système de haut-parleur
US10212526B2 (en) Acoustic pressure reducer and engineered leak
Boulandet et al. Sensorless electroacoustic absorbers through synthesized impedance control for damping low-frequency modes in cavities
GB2532794A (en) Versatile electroacoustic diffuser-absorber
US6801628B1 (en) System and method for adjusting frequency response characteristics of a speaker based upon placement near a wall or other acoustically-reflective surface
Rivet Room modal equalisation with electroacoustic absorbers
Liu et al. Characterization of a Tunable Electromechanical Helmholtz Resonator
TW213531B (fr)
JP2000506321A (ja) 音響部材と音響処理方法
Huang et al. Analysis of total harmonic distortion of miniature loudspeakers used in mobile phones considering nonlinear acoustic damping
Narine Active noise cancellation of drone propeller noise through waveform approximation and pitch-shifting
Lissek et al. A preliminary study of an isodynamic transducer for use in active acoustic materials
Bai et al. Robust control of a sensorless bass-enhanced moving-coil loudspeaker system
CN112233638B (zh) 一种可调的低频消声结构的设计方法
JP2003299168A (ja) スピーカシステム
WO2020143472A1 (fr) Procédé de correction de propriétés acoustiques d'un haut-parleur, dispositif audio et dispositif électronique
CN112104956A (zh) 被动辐射器和包含被动辐射器的电声装置
JP2737930B2 (ja) 電子楽器

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20170621

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20180322

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: CH

Ref legal event code: NV

Representative=s name: ANDRE ROLAND S.A., CH

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 1039319

Country of ref document: AT

Kind code of ref document: T

Effective date: 20180915

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602015015890

Country of ref document: DE

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20180905

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181206

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 1039319

Country of ref document: AT

Kind code of ref document: T

Effective date: 20180905

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190105

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190105

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602015015890

Country of ref document: DE

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20181123

26N No opposition filed

Effective date: 20190606

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20181130

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20181123

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20181130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20181123

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MK

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180905

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20151123

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180905

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230523

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20231123

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20231120

Year of fee payment: 9

Ref country code: DE

Payment date: 20231121

Year of fee payment: 9

Ref country code: CH

Payment date: 20231201

Year of fee payment: 9