WO2016110876A1 - Dispositif de diffraction acoustique à guide d'ondes - Google Patents

Dispositif de diffraction acoustique à guide d'ondes Download PDF

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Publication number
WO2016110876A1
WO2016110876A1 PCT/IT2015/000310 IT2015000310W WO2016110876A1 WO 2016110876 A1 WO2016110876 A1 WO 2016110876A1 IT 2015000310 W IT2015000310 W IT 2015000310W WO 2016110876 A1 WO2016110876 A1 WO 2016110876A1
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WO
WIPO (PCT)
Prior art keywords
waveguide
acoustic
loudspeaker
sound waves
diffracting device
Prior art date
Application number
PCT/IT2015/000310
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English (en)
Inventor
Claudio GANDOLFI
Original Assignee
Robin S.R.L.
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 Robin S.R.L. filed Critical Robin S.R.L.
Priority to EP15848137.4A priority Critical patent/EP3243334A1/fr
Publication of WO2016110876A1 publication Critical patent/WO2016110876A1/fr

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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
    • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
    • H04R1/026—Supports for loudspeaker casings
    • 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
    • H04R1/2853—Enclosures comprising vibrating or resonating arrangements using an acoustic labyrinth or a transmission line
    • H04R1/2857—Enclosures comprising vibrating or resonating arrangements using an acoustic labyrinth or a transmission line 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
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H04R1/34—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means
    • H04R1/345—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means for loudspeakers

Definitions

  • the present invention deals with a waveguide acoustic diffracting device. It is an acoustic diffuser with omni-directional emission horizontally on the whole audio band, and capable of generating a realistic sound field.
  • the structure is extremely lightweight, can be made with economic materials which can be easily found and worked.
  • the diffraction produced by the edges is an undesired effect which tends to be minimized: on the contrary, the present invention makes use of a geometry which maximizes its effects .
  • the positioning of the acoustic diffusers in the listening environment is critical. Sound waves which directly arrive from the transducers to the listening point precede the reflections generated by walls and objects present in the environment. Too many reflections make listening confused, too few reflections make sound unnatural since hearing does not allow mentally reconstructing realistic environment features .
  • a first object of the present invention is facilitating the positioning of the acoustic diffuser in the environment and making hearing realistic.
  • the first wave front (18) perceived by the listener is related to the sound wave moving along the shortest distance between loudspeaker (5) and the listening point (15).
  • secondary sound waves (38, 48) are emitted by diffraction with wave fronts delayed by the path inside the waveguide (6) which reach the listening point before the reflections generated by wall and objects present in the listening environment.
  • Intensity and delays of the secondary waves (38, 48) are identical for the two stereo channels, are controllable at design level and prevail at psycho-acoustic level on the reflections of the listening environment, making realistic the reproduced sound field,
  • the omnidirectional horizontal emission avoids that the sound energy concentrated on a single object or wall in the environment generates reflections which result predominant or excessive in a part of the audio spectrum.
  • the sound of a music instrument derives from the combination of vibration modes of its parts, and at the same time sound waves are generated in different points of its structure.
  • the sizes of the instruments change in the majority of cases from 50 cm to a couple od meters, so that sound waves simultaneously emitted by different parts can arrive at a listener with wave fronts offset by a few milliseconds.
  • the offset between wave fronts generated by sound waves emitted at the same time is further increased by the possible paths of the reflections in the listening environment.
  • the delays introduced by offsets contribute to the perception of the characteristics both of the sound emitted by the instrument and of the environment in which one listens.
  • a second object of the present invention is simulating the size of the music instrument by emitting fractions of sound energy of the same wave many times, with increasing delays and in different positions .
  • FIG. 1 is a schematic sectional detailed view of a loudspeaker used in the diffracting device according to a first preferred embodiment of the present invention
  • FIG. 2 is a front schematic sectional view of the diffracting device of Figure 1;
  • FIG. 3 is a front view of the diffracting device of Figure 2;
  • Figure 4 schematically shows an arrangement with two diffracting devices per channel
  • Figure 5 schematically shows another arrangement with two diffracting devices
  • Figure 6 shows the diffracting device of the present invention applied to conventional loudspeakers
  • Figure 7 is a front view of the diffracting device according to a second preferred embodiment of the present invention
  • Figure 8 is a front schematic sectional view of the diffracting device of Figure 7;
  • Figure 9 is a top schematic view of the diffracting device of Figure 7.
  • Figure 10 shows in section a detail of the base of the loudspeaker of the diffracting device of Figure 7;
  • Figure 11 shows the path of the sound waves emitted by the rear side of the loudspeaker and the path related to secondary sound waves emitted by diffraction from an hole in the centre of the waveguide and an hole at the end of the waveguide;
  • Figure 12 shows the behaviour of the acoustic pressure in the listening point for an acoustic signal, formed by only one 1- kHz positive half-wave, sent to the loudspeaker considering only the rear emission and the one from the holes;
  • - Figure 13 shows a virtual configuration capable of generating the behavior of the acoustic pressure shown in Figure 12;
  • FIG. 14 shows the omnidirectional distribution of the secondary sound waves emitted by diffraction and the main forces generated by the diffraction itself
  • FIG. 16 shows how the acoustic diffracting device can be used in a 2-way system
  • FIG. 18 shows the section of a plug, which covers the upper opening of the waveguide of Figure 7.
  • the sound energy (8) emitted by the loudspeaker (5) is sent inside a waveguide
  • the energy of the single wave front (8) emitted by the loudspeaker (5) membrane is divided into a series of spherical fronts emitted with increasing delays from mutually aligned and spaced holes
  • the sound diffraction depends on the speed of sound in air and on geometric parameters of the acoustic diffracting device: therefore, the wave fronts emitted in different points and in different times are propagated with predetermined phase delays also in the listening point.
  • the sum of the spherical fronts prevails on the effect of the reflections of the listening environment, facilitating the recognition of single sounds, making the reproduction more realistic and reducing the position criticality both of the diffusers, and of the listener.
  • a waveguide (6) preferably 1 meter long, fastened to the loudspeaker (5), allows generating delays from 0 to about 3 milliseconds.
  • the waveguide (6) has also a function of screen to reproduce low frequencies, since it prevents the acoustic short circuit between front and rear emissions of the loudspeaker (5) .
  • a series of holes (7) a few millimeters long, aligned at a distance of 1 cm on the side part of the waveguide (6), are used for the delayed diffraction of the wave fronts.
  • the holes (7) have sizes lower than the lengths of the sound waves to be reproduced, and therefore they behave as omni-directional acoustic radiators.
  • the waveguide (6) keeps the phase coherence of internal wave fronts for its whole length, and allows positioning the loudspeakers (5) at the base of the acoustic box, facilitating the removal of undesired vibrations between floor and loudspeakers.
  • the internal wave fronts (8) apply a perpendicular pressure on the internal side surface of the waveguide (6) .
  • the internal wave fronts (8) apply a perpendicular pressure on the internal side surface of the waveguide (6) .
  • the acoustic transformer of the waveguide type is a technology which allows obtaining the same type of sound field, as disclosed in documents SS2013A0000007 and PCT/2014/000128 of the same Applicant of the present invention.
  • time and space offsets of the wave fronts are obtained by exploiting the waveguide deformation with the limit of linearity of the deformation itself, which appears on low frequencies at high power.
  • the waveguide acoustic diffracting device there are no structure parts which can be deformed by the sound waves, thereby the whole power of the loudspeakers can be used also at low frequencies.
  • the Applicant has made a prototype of the inventive diffracting device in the following way.
  • a metallic bit (2) On a wooden base (1) a metallic bit (2) has been fastened, which is a fulcrum to support the magnet (4) of the loudspeaker (5) kept suspended in a balance at about 1 millimetre from the base (1) .
  • the bit (2) acoustically uncouples the base (1) on the floor and the loudspeaker (5) .
  • the waveguide (6) On the front side of the loudspeaker (5), the waveguide (6) is fastened with a cylinder 1 meter high and with a diameter of about 8 cm and its top side open. Along the side wall the 2-mm holes (7) are aligned at a distance of 1 cm oriented towards the listening point.
  • the sound waves (8) emitted from the front side of the loudspeaker (5) are send inside the waveguide (6) and, by moving along it, interact with the holes (7) which become the originating points of the spherical wave fronts.
  • the sound waves (8) go out of the upper side of the cylinder, which is a further generating point of diffracted spherical waves for medium and low frequencies.
  • the highest, directive frequencies continue upwards and afterwards are reflected by the room ceiling.
  • the envelope of sounds generated by instruments is divided into the phases of attack, decay, holding and release.
  • the phases of attack, decay and release are transients with very quick amplitude variations of the sound pressure which can be assimilated to pulses.
  • the pulse response of the waveguide acoustic diffracting device is optimized by the reduced reflections added to the diffuser structure.
  • the wave front (8) emitted upwards is diffused in the environment by crossing the waveguide.
  • the wave front emitted downwards is diffused in the environment only from the floor.
  • Vibrations transmitted to the loudspeaker (5) basket from the movement of the membrane are mainly directed vertically and neglectably interact with the wave fronts generated by diffraction which propagate horizontally.
  • the waveguide acoustic diffracting device generates a series of wave fronts in different times and positions, using fractions of energy of the same pulse.
  • the coherence of the phase delays is greater with respect to the one normally provided by acoustic boxes with direct radiation with the reflection of the listening environment and the reconstruction of a model of the sound source is more realistic.
  • the phase of holding can be assimilated, as a first approximation, to a stationary regime.
  • the real instrument emits energy from different structure areas which simultaneously irradiate towards the listening point.
  • the sound energy is distributed in space on many simultaneously emitted fronts.
  • the sum of spherical fronts generated by the aligned holes (7) can be described as a cylindrical surface which horizontally propagates towards the listening point, in which the pressure is vertically modulated along the direction of the sound waves (8) inside the waveguide.
  • the cylindrical surfaces generated in succession have pressure profiles translated along the direction of the cylinder axis. While the sound waves interact with the pinna, they transport information related both to the horizontal movement, and to the vertical displacement of the pressure profile, facilitating the sound decoding.
  • the pressure maxima generated by the loudspeaker in different times are simultaneously present next to the holes (7) at a distance equal to the wavelength.
  • the sound waves propagate by complying with the Huygens principle and reach the listening point, transferring onto the surface which contains it the same pressure maxima.
  • the re production realism derives from the simulation of different wave fronts generated by the instrument at the same time with wave fronts generated by the loudspeaker in different times.
  • the shape of the waveguide (6) can be changed, provided that it keeps the phase coherence between the frequencies of the wave trains (8) which cross it.
  • the distribution of holes on the side surface of the waveguide can be changed depending on design needs. By modifying density and alignment of the holes, the emission can be kept at 360 degrees of the sound energy related to some frequencies can be concentrated in pre-determined angular sectors.
  • the distribution of holes can be used to constructively or destructively interact with some frequencies present inside the waveguide.
  • the acoustic screen effect of the waveguide is reduced, together with the response at low frequencies.
  • Some types of loudspeakers are designed to work in closed volumes, so that in these cases it is convenient to use waveguides with the opposite end to the loudspeaker closed and the diffraction reduced.
  • the function of the waveguide acoustic diffracting device as omni-directional acoustic radiator for high frequencies can also be applied to conventional acoustic boxes (11), as can be seen in Figure 6. It is enough to orient the loudspeaker (5) upwards and abut thereon the cylinder-shaped waveguide (12) with a slit on the side wall .
  • the function of the waveguide acoustic diffracting device as acoustic impedance adaptor for low frequencies requires sizes on the order of a meter, and therefore resonances can be triggered inside the waveguide (6). These are resonances whose frequency is related with the sizes.
  • Figure 4 shows a possible configuration with a double waveguide. For every channel, there are two loudspeakers and two waveguides.
  • the waveguide (9) maximized the emission by diffraction with a continuous slit some millimetres long.
  • the waveguide (7) has a series of 2-mm holes and a reduced diffraction, and the upper side is open in order to use air inside as additional mass which lowers the resonance frequency of the diffuser.
  • Figure 5 shows the acoustic diffracting device (9) coupled with a subwoofer ( 10 ) .
  • a sheet of 350-g/mq cardstock bent with an octagonal section is the waveguide open at its sides used in the waveguide acoustic diffracting device.
  • the position near the floor for the loudspeaker has two advantages: it simplifies the construction of the diffuser and facilitates the removal of undesired vibrations.
  • the loudspeaker there remains only the waveguide (6), fastened to the flange of the loudspeaker (5), which can also be made of very lightweight materials like cardstock.
  • the barycentre of the diffuser is near the floor and coincides with the loudspeaker: this makes the acoustic diffuser stable.
  • the sound wave (18) emitted from the rear side of the loudspeaker (5) is directly sent in the listening environment.
  • the sound wave (28) emitted by the front side of the loudspeaker (5) is sent inside a waveguide (6).
  • the waveguide has no transverse projections so that the wave emitted at floor level for the loudspeaker (5) travels up to the ears of a listener (15) without generating reflections and finally goes out of the open side (9) of the waveguide.
  • the internal sound wave generates by diffraction, next to the holes (7), secondary sound waves (38, 48) with increasing delays with respect to the sound wave emitted from the rear side of the loudspeaker (18) and with spherical wave fronts (Fig. 14) with a centre next to the holes (7) .
  • the sound diffraction depends on the speed of sound in air and on geometric parameters of the acoustic diffracting device: therefore, the secondary sound waves emitted by diffraction in different points and at different times propagate themselves with predetermined intensity and delays also in the listening point. Intensity and delays are identical for the two stereo channels.
  • the secondary sound waves reach the listening point before the reflections generated by the walls of the listening room.
  • the effect of the secondary sound waves (38, 48) diffracted by the diffuser prevails on the effect of the reflections of the listening environment, facilitating the recognition of single sounds, making the reproduction more realistic and reducing the criticality of the position both of the diffusers, and of the listener.
  • Every hole (7) is coplanar with other three holes symmetrically distributed at the same distance of the loudspeaker.
  • An omnidirectional horizontal emission is obtained, on the whole audio band from 20 Hz to 20 KHz, efficient on an angle of 360 degrees as pointed out in Figure 14.
  • the holes symmetry makes null the resultant of the forces deriving from diffractive phenomena, reducing to a minimum the perturbation of the internal sound wave (8) .
  • the omni-directional horizontal emission avoids that the sound energy is concentrated in some angular sectors in which there are objects or walls capable of generating excessive reflections in part of the audio spectrum.
  • the sound field produced by the waveguide acoustic diffracting device is equivalent to the one produced by a virtual loudspeaker (5') placed next to the diffuser and at the height of the ears of the listener (15), surrounded by a series of acoustically reflecting panels (37', 47') on the back with respect to the virtual loudspeaker (5') if seen from the listening point (15) .
  • the distance between virtual panels (37', 47') and virtual loudspeaker (5') is about half the distance between real loudspeaker (5) and diffraction holes (37, 47) .
  • the horizontal emission is omni-directional, so that if the listener (15) moves, also the virtual panels (37', 47') move behind the virtual loudspeaker (5') which remains fixed.
  • the listener can freely move in front of the diffusers, always having an optimum stereophonic image. Also in case of many people sitting in front of the diffusers, all will listen under optimum acoustic conditions.
  • the air volume contained inside the waveguide (6) open on the upper side (9) has a mass which is added to the moving mass of the loudspeaker (5) reducing the resonance frequency and improving the response of the acoustic diffracting device at low frequencies.
  • the efficiency of the acoustic screen composed of the waveguide (6) can also be obtained with materials capable of being deformed by the sound waves, like the cardstock.
  • the density of a 350-g/mq cardstock is enough to confine the sound waves emitted inside the waveguide (6).
  • the non-elastic deformations of the cardstock are used to dissipate acoustic energy and dampen the low frequencies inside the waveguide (6).
  • Medium and high frequencies are not attenuated, since inertia due to the cardstock mass prevents appreciable deformations from being generated.
  • the maximum linear deformation of the section of the waveguide due to the internal acoustic pressure limits the maximum acoustic pressure which can be used by the acoustic diffracting device.
  • the presence of the octagon edges increases the maximum linear deformation.
  • the octagonal section has been chosen for its easy making and can be replaced by other shapes which keep the symmetry with respect to the axis of the waveguide (6) with bends which facilitate its deformation.
  • the bends compose ribs which increase the mechanical sturdiness, making it suitable to obtain self-carrying waveguides even one meter long .
  • the time and space offsets of the sound waves are obtained by exploiting the deformation of the waveguide to emit secondary sound waves.
  • the linearity limit of the deformation which reduces the maximum sound which can be reproduced.
  • Another limit of the acoustic transformer is at highest frequencies, where the density of the waveguide membrane becomes important.
  • the waveguide acoustic diffracting device does not exploit the deformation of the structure for emitting the secondary sound waves, so that the whole power of the loudspeakers at low frequencies can be used, and high frequencies can also be optimally reproduced.
  • the waveguide (6) has no transverse projections which could generate reflections or perturb the sound waves (8) which cross it.
  • the waveguide (6) made of rigid materials like wood or plastics makes the acoustic diffracting device adapted for mobile installations and/or for outside.
  • the Applicant has also made a prototype of the diffracting device of the above described second embodiment.
  • Paper is a non-elastic material which prevents the formation of undesired vibrations between loudspeaker (5) and floor which, being propagated to the structure of the diffuser, would mask the effect produced by the secondary waves (38, 48) .
  • the waveguide (6) On the front side of the loudspeaker (5), the waveguide (6) is fastened and made with a 1 meter high tube, the section of an octagon with a 4-cm apothem and the upper side open, Along the side wall the 3-mm holes (7) are aligned at a distance of 1 cm arranged on four symmetrical rows with respect to the axis of the waveguide.
  • the sound waves (28) emitted from the front side of the loudspeaker (5) are sent inside the waveguide (6) and, moving along it, interact with the holes (37, 47) which become points of origin of diffracted secondary sound waves with spherical wave fronts (7).
  • the sound waves go out of the upper side of the cylinder (9), which is a further point of generation of diffracted secondary sound waves with spherical wave fronts for medium and low frequencies.
  • the highest frequencies, directive go on upwards and are afterwards reflected by the room ceiling.
  • the sound waves emitted from the rear side of the loudspeaker (18), at a height of few centimetres with respect to the floor, are directly irradiated in the listening environment without meeting further obstacles.
  • the envelope of sounds generated by instruments is divided into the phases of attack, decay, keeping and release.
  • the phases of attack, decay and release are transients with very quick amplitude variations of the sound pressure which can be assimilated to pulses.
  • the phase of keeping can be assimilated as first approximation to a stationary regime.
  • the impulse response of the waveguide acoustic diffracting device is optimized by the lack of reflections added to the structure of the diffuser.
  • the sound wave (28) emitted upwards is diffused in the environment by crossing the waveguide (6) .
  • the sound wave emitted downwards is diffused in the environment limited only by the floor.
  • the waveguide acoustic diffracting device generates a series of secondary sound waves in different times and positions, using fractions of energy of the same pulse,
  • the phase delays between the secondary sound waves are predetermined by the geometry of the acoustic diffracting device, are identical for the two channels and allow an accurate reconstruction of the stereophonic image.
  • the real instrument emits energy from different areas of the structure which are simultaneously irradiated towards the listening point.
  • the sound energy is distributed in the space on many simultaneously emitted waves.
  • the sum of the secondary sound waves with spherical wave fronts generated by the holes ( 7 ) creates a complex dynamical system which can be assimilated to a cylinder with the same axis of the acoustic diffracting device and which horizontally expands towards the listening point.
  • the modulation profiles of the acoustic pressure translate upwards due to the delays generated inside the waveguide (6).
  • the secondary sound waves interact with the pinna, they transport information related both to the horizontal movement, and to the vertical movement of the pressure profile, facilitating the sound decoding.
  • the re production realism can be attributed to the fact that in the listening point many secondary sound waves generated by the loudspeaker at different times simulate the sound waves generated by the instruments at the same time in different points of its structure.
  • the distribution of holes on the side surface of the waveguide can be changed depending on design needs. Many holes can be joined in a slit to increase the sound energy transmitted outside, The same upper open section of the waveguide originates diffraction phenomena. In general, by increasing the energy emitted by diffraction, the acoustic screen effect of the waveguide is reduced, together with the response at low frequencies.
  • a mobile plug (10) made of acoustically reflecting material allows using loudspeakers designed to work in closed volumes.
  • a plug (10) made of a thin sheet of paper leaves unchanged the acoustic characteristics and protects from dust the acoustic diffracting device interior.
  • acoustic box is the most suitable for classifying the waveguide acoustic diffracting device made of cardstock.
  • the cardstock is not suitable for being used in the open, in humid environments or in mobile installations subjected to impacts during transport.
  • a material can be used which is more resistant to impacts and to humidity, like plastics or wood.
  • the acoustic diffracting device becomes heavier and there is a slight loss of quality due to the fact that materials like plastics or wood have more elasticity with respect to cardstock and facilitate the formation of spurious vibrations in the structure.
  • the function of the waveguide acoustic diffracting device as omni-directional acoustic radiator for high frequencies can also be applied to multi-way acoustic boxes, as shown in Figure 16.
  • the tweeter (5) is oriented upwards, and on it the waveguide (12) is fastened, shaped as an octagon with four slits (7) on the side walls.
  • the function of the waveguide acoustic diffracting device as acoustic impedance adapter for low frequencies requires sizes on the order of the metre, and therefore resonances can be triggered inside the waveguide (6) . These are resonances whose frequency is related to the sizes.
  • the problem can be soled with a DSP which allows compensating also possible resonances generated by the listening environment. In order to perceive the realistic sound reconstruction, it is necessary that the whole reproduction chain is of an adequate level. Distortions and/or background noises can cover information which are sent by minimum phase variations of the secondary sound waves and also the interaction between diffuser and floor can degrade the reproduction quality.
  • the latter prototype has a total weight of 675 grams only, including electric connections.
  • the loudspeaker by itself weights 525 grams.
  • an acoustic diffuser is obtained with an audiophile quality, capable of generating over 90 dB of acoustic pressure in a house environment.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)

Abstract

Dispositif de diffraction acoustique à guide d'ondes comprenant : un guide d'ondes (6), d'une forme allongée et de section octogonale, ouvert au niveau de ses côtés et constitué d'une feuille de papier cartonné pliée, un haut-parleur (5) conçu pour produire des ondes sonores (8) envoyées à l'intérieur du guide d'ondes (6) et pour supporter le guide d'ondes (6) fixé à la bride du haut-parleur (5), une base de support composée d'un double anneau cylindrique (22, 23) qui maintient le haut-parleur (5) en position, l'isolant acoustiquement du sol, le guide d'ondes (6) ayant de nombreuses séries de trous (7) sur la paroi latérale et effectuant simultanément les fonctions suivantes : a) guide d'ondes (6), b) radiateur acoustique passif omnidirectionnel, c) retard acoustique, d), contenant, e) écran, f) dissipateur non élastique d'énergie acoustique, g) élément structural léger et auto-portant.
PCT/IT2015/000310 2015-01-08 2015-12-15 Dispositif de diffraction acoustique à guide d'ondes WO2016110876A1 (fr)

Priority Applications (1)

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EP15848137.4A EP3243334A1 (fr) 2015-01-08 2015-12-15 Dispositif de diffraction acoustique à guide d'ondes

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ITTO20150007 2015-01-08
ITTO2015A000007 2015-01-08

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111818406A (zh) * 2020-06-01 2020-10-23 深圳易科声光科技股份有限公司 声音扩散装置
CN112611921A (zh) * 2020-12-09 2021-04-06 上海无线电设备研究所 一种大气声场模拟装置及其电磁散射特性测试方法
EP3820160A1 (fr) * 2019-11-06 2021-05-12 Samsung Electronics Co., Ltd. Haut-parleur et appareil de sortie de son le comprenant

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FR2620891A1 (fr) * 1987-09-18 1989-03-24 Bernard Georges Cone d'ecoulement pour les bruits parasites utilisable notamment pour les appareils de haute-fidelite
US5552569A (en) * 1995-03-08 1996-09-03 Sapkowski; Mechislao Exponential multi-ported acoustic enclosure
US20090252363A1 (en) * 2008-04-03 2009-10-08 Ickler Christopher B Loudspeaker Assembly

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2620891A1 (fr) * 1987-09-18 1989-03-24 Bernard Georges Cone d'ecoulement pour les bruits parasites utilisable notamment pour les appareils de haute-fidelite
US5552569A (en) * 1995-03-08 1996-09-03 Sapkowski; Mechislao Exponential multi-ported acoustic enclosure
US20090252363A1 (en) * 2008-04-03 2009-10-08 Ickler Christopher B Loudspeaker Assembly

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3820160A1 (fr) * 2019-11-06 2021-05-12 Samsung Electronics Co., Ltd. Haut-parleur et appareil de sortie de son le comprenant
US11259114B2 (en) 2019-11-06 2022-02-22 Samsung Electronics Co., Ltd. Loudspeaker and sound outputting apparatus having the same
CN111818406A (zh) * 2020-06-01 2020-10-23 深圳易科声光科技股份有限公司 声音扩散装置
CN112611921A (zh) * 2020-12-09 2021-04-06 上海无线电设备研究所 一种大气声场模拟装置及其电磁散射特性测试方法

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