CN1143593C - Acoustic device relying on bending wave action - Google Patents
Acoustic device relying on bending wave action Download PDFInfo
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- CN1143593C CN1143593C CNB998046930A CN99804693A CN1143593C CN 1143593 C CN1143593 C CN 1143593C CN B998046930 A CNB998046930 A CN B998046930A CN 99804693 A CN99804693 A CN 99804693A CN 1143593 C CN1143593 C CN 1143593C
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
- H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
- H04R7/04—Plane diaphragms
- H04R7/06—Plane diaphragms comprising a plurality of sections or layers
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
- H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
- H04R7/04—Plane diaphragms
- H04R7/045—Plane diaphragms using the distributed mode principle, i.e. whereby the acoustic radiation is emanated from uniformly distributed free bending wave vibration induced in a stiff panel and not from pistonic motion
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
- H04R7/16—Mounting or tensioning of diaphragms or cones
- H04R7/18—Mounting or tensioning of diaphragms or cones at the periphery
- H04R7/22—Clamping rim of diaphragm or cone against seating
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- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
- Piezo-Electric Transducers For Audible Bands (AREA)
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
- Respiratory Apparatuses And Protective Means (AREA)
- Toys (AREA)
- Orthopedics, Nursing, And Contraception (AREA)
- Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
- Ultra Sonic Daignosis Equipment (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
Acoustic device comprising a member relying on bending wave action with beneficial distribution of resonant modes thereof, wherein the member has its acoustically active area at least partly bounded by means having a substantially restraining nature in relation to bending wave vibration. Operation can be below coincidence, or above if desired for active acoustic device further having beneficial location of bending wave transducer means determined with reference to and taking account of such bounding means.
Description
The present invention relates to a kind of acoustic apparatus, comprise audio emission parts, it relies on bending wave action and synthetic surface vibration to produce voice output.
U.S. Pat 3 from WARNAKA, 247, a kind of woofer that constitutes by extremely hard resonance panel of 925 known propositions, the surrounding edge of this panel is by bolt or be adhesively fixed on hard framework, this framework is supported traditional voice coil loudspeaker voice coil transducer, and this transducer is given the center of panel the energy delivery of bending wave.Allegedly this woofer device is done on the frequency at phase of wave fully and is operated.
From a kind of loud speaker that has by the formed diaphragm of the tabular parts of polystyrene that extends of the also known proposition of the U.S. Pat 3596733 of BERTAGNI, the tabular parts of this polystyrene have the front surface and the rear surface of tensioning in advance, surface wherein for or comprise irregular shape.
The instructive that is regarded as the bending wave action acoustic apparatus of general resonance surface board type for simplicity is taught in the International Patent Application WO 97/09842 to be pointed out, comprise according to panel parameter coming sound performance is improved or optimizes, these parameters comprise how much and bending stiffness, especially are included in spendable operation under coincidence frequency or this frequency.The ratio that interested geometric parameter comprises this class panel is the shape ratio in other words, comprises coming as the passive acoustic device.The bending stiffness parameter can interact with geometric parameter effectively, these geometric parameters comprise its anisotropy, that is to say that along the axle of geometry it has different bending stiffnesses or can decompose bending stiffness on the direction of basically identical along the axle of geometry, these geometries are that feasible changes of ratio of this shape is routine.The interior position of preferred plate that is used for the transducer of active acoustic apparatus has proportional qualification coordinate effectively.Other face of bending stiffness distributes and can help transducer provided other useful positions effectively, for example basically in geometric center or in the center of quality, this point please refer to International Patent Application WO 98/00621, and it comprises piston action further relevant on aforesaid bending wave action and the sound combined.At least in WO97/09842, describe and claimed on the acoustics being the active whole front panel and wherein the acoustic operation of a part only.
On the intuition basis, specific analysis and method for designing that we implement for this resonance mode bending wave action acoustic apparatus mainly concentrate on the whole front panel, be fully or basically can free vibration in the time of wherein in relevant on being in acoustics, the required bending wave action in edge, these edges comprise the part that is subjected to light edge damping.The present invention is from the result who is taken aback with people in addition counter-intuitive that obtain after further considering, study and testing.
Some potential requirement continues to be suitable for and to have the importance of deep technology/creation aspect, be particularly useful for a kind of acoustic apparatus parts, also can keep bending wave to pass through its sound active zone along its thickness extending transversely, this is for the basic demand that is called as resonance sound parts or panel here; These parts also are used for such as the parameter of geometric parameter and are used for bending stiffness making it to have the synthetic consistent value of vibrating with described parts natural torsion ripple that distributes, these parts on interested frequency range, obtain device required or acceptable acoustic operation aspect be effective or useful, promptly be the further requirement that is used for resonance sound parts or the panel here.Specific embodiment of the present invention also provides a kind of device, this device usually at the edge of this parts or panel or its sound active zone, on every side or other boundary the remarkable restriction of bending wave vibration is provided, and can at least a portion frequency under the coincidence frequency, operate at least usually.Word used herein " significantly restriction " means contrast and specifically is disclosed in the bigger restriction at least a portion edge of these parts among the WO97/09842, preferably to edge extent and Payload, clamping or the effectively restriction of ground connection effect.
From two aspects, effect or creationary aspect, consider that this firm edge/regional border/restriction on every side is useful.
One is, to the restriction/minimizing that the available bending wave vibration edge of parts/on every side/moves on the border (openly comparing), can produce from the acoustics the vibration bending wave energy of active zone postmedian and obtain the useful compound of voice output with specific among the WO97/09842.Another is, relevant and the effective natural mode of the acoustics of resonance bending wave action is different (openly comparing with specific among the WO97/09842), this be because at the edge of parts/on every side/boundary restriction/inhibition bending wave vibration moves, thereby reduce the effect of eliminating from minimum resonance mode effectively, if and the edge of the sound active zone of parts/on every side/border is freely, have with WO97/09842 in specificly disclose identical bending wave and distribute, then this minimum resonance mode is effective; Also owing to reduce/the remarkable resonance mode that suppresses to relate to distortion.
Nominally the more sparse or sound still less that produces effectively/relevant resonance bending wave component, just can carry out example separates, simulation that is used to simplify or analysis, this simulation or analysis are based on the simple bundle of the interactional equivalence of having considered relevant sounding board mode, these sounding board mode with respectively get off relevant, and from resonance mode frequency f 1 rather than f0, and " remove " combined modality that relates to the f0 frequency, but have interested and useful effect, this effect can be from obtaining with respect to the evenness direct and interval of relevant natural resonance mode in combination that relates to the f1 frequency.
Difference (ramifications) is widely and is favourable, comprises the availability of the acoustic efficiency of improved power conversion; And/or very usefully increase candidate's subregion usually, so that the availability of feasible/optimization transducer position to be provided, be in the International Patent Application PCT/GB99/00404 of pending trial, to instruct the position of identifying by the mechanical impedance analysis like that at least; And/or, compare with being used for illustrating of isotropic bending stiffness, the usability area of the region shape/ratio of described parts is much bigger usually, even shape than at about 1: 1 under about 1: 3 or bigger situation; And/or intrinsic bending stiffness is low and at least because from the effect of its edge/on every side/boundary limitation and the whole availability of the sound performance of the panel component material of sclerosis effectively; And/or, with the relevant performance of high power input transducer apparatus that is used for loud speaker embodiment, all this restrictions that all comprise can provide remarkable load, or based on the inertia ground, or become in harder/heavy carrier or other heavy duty mode by actual fixed and more to correspond to reality.
A significant advantage of the present invention provides novel and useful resonance panel acoustic apparatus, comprise active acoustic apparatus as loud speaker, can make easily, become the template device of solid easy installation, especially in the International Patent Application WO 97/09842 the acoustic apparatus of special diagram and explanation improve.
According to an aspect of the present invention, a kind of acoustic apparatus is provided, it relies on bending wave action and can operate below coincidence frequency, comprise that resonance mode owing to wherein bending wave action is provided parts of described acoustic operation by advantageously distributing, wherein the sound active zone of these parts device that had remarkable limit flexion ripple vibration characteristics at least in part defines.
According to a further aspect in the invention, a kind of active acoustic apparatus is provided, comprise parts that have the useful distribution of resonance mode, the useful position of bending wave transducer apparatus and depend on bending wave action, wherein the device that had remarkable limit flexion ripple vibration characteristics at least in part of the active zone on the acoustics of these parts defines, and the reference by location of its transducer apparatus and consider that this device that defines determines.
The entire circumference of sound components can significantly limit or clamp; One or morely be limited up to its whole lateral edges place or clamp at it around perhaps these parts rectangular slab for example, its part rather than all.This can be used as provides the flag of described remarkable restriction shape to install on one side, and the sound active zone is stretched therefrom; Perhaps as the installation on parallel dual-side, these two sides provide remarkable restriction, and the sound active zone is installed between the restriction side at these.And can be convenient to like this produce have whole sealings or the loud speaker of the diaphragm of high selectivity opening only, for example in/high-frequency device.Seal membrane can be made so-called infinite baffle (baffle) loud speaker all or almost all, comprise/control the rear portion audio emission, otherwise this is harmful to low frequency in being transmitted in.
Whole remarkable restriction and clamping frames also make the design of loudspeaker assembly more measurable in mechanical aspects, be convenient to the manufacturing of loudspeaker assembly simultaneously, this loud speaker is quite solid (is that the resonance panel loudspeaker that freely or only is draped with a kind of elastic type of slight damping is compared substantially with face plate edge) in configuration aspects.
The remarkable restriction at peripheral part of sound components or edge or clamping can obtain in the mode of any needs, for example by the edge closely is fixed on solid framework etc. with bonding mode, or by for example the edge being clamped in the mechanical means between the frame parts.Here edge limitation/the clamping that needs also can be prevented the edge of sound components to move with the edge that forms parts by molding technology (as the injection molding of plastic material) and realize by assigning to the periphery that the whole of enough rigidity is arranged or be combined into whole thickening.The co-molded of the edge setting of sound components and thickening is suitable.This molding technology is particularly suitable for being used in the situation that sound components forms single-piece and can easily obtain in the mode of economy.
Significantly restriction or clamping also can be used to limit a sound components in another bigger sound components.Thereby in planning to be used in/the big acoustic panels of low frequency operation can carry out molding and comprise and plan the less acoustic panels that is used in high-frequency operation and limited by the hard floor in centre.
Can design remarkable restriction or clamping action, the mechanical terminations impedance is provided, this impedance design is used for being controlled at the reverberation time in the sound components, helps the frequency response of control to parts, at the low frequency place perhaps especially like this.
The ratio of suitable resonance surface plate member aspect the variation of given shape can be or be different from certain teachings among the WO97/09842 basically.For example, having roughly, the resonance surface plate member that is roughly rectangle of isotropic bending stiffness has at the ratio of the shape below 1: 1.5, therefore, generally speaking comprise the instruction of prior art for the panel component that is essentially free edge, but be not restricted to this, the this point back will specifically describe, and perhaps the shape ratio was greater than 1: 1.5, and this point back also specifically describes.The variation of the distribution of the anisotropy/complexity of bending stiffness as top, also can be expected.
Define device and can be at least in part around described sound active zone and restriction, and/or, around the parts of panel-form so that its integral body to be sound effective, normally up to 25% or bigger scope of whole zone boundary/surrounding edge scope, its gamut normally.
The resonance surface plate member normally from supporting and do not need tensioning in advance to obtain mechanical stability, the type of using in particular for the type of free edge form or simple edges support.
For the panel component that clamps, because the air-set of panel component makes in first inflection frequency raising about 10 times is arranged when clamped.Significantly reducing the bending stiffness performance before lower frequency range, to reduce by first model frequency be reasonable and sensitive.Can expect that the rigidity of panel component can be low to moderate 0.001Nm in this case, surface density is little of 25g/m
2
From a viewpoint, these end points of value range are described a kind of panel component, can have benefited from the application of these tension force for the function of mechanical stability and drive unit support.These tension force can evenly apply with respect to effective geometry of parts, also can differently apply promptly different directions or different tension force sizes.
At the limiting value place, the panel of tensioning shows the high balance of the tensioning film properties of supporting bending wave and is mainly second order or not discrete ripple effect (speed is constant for frequency).For this " panel " parts, can be for the sound behavior of needs by control and broadly consistent tension force and the border of distributed mode instruction. geometry is optimized resonant contribution, and this instruction is please referring to WO97/09842.Similarly, a preferred modal distribution can further be enhanced to replace exciter/transducer as the transducer through preferred/optimization.
According to the size of tension force and along with the raising of density and especially bending stiffness, a scope is arranged, second order bending wave action in this scope since hardness by quadravalence, disperse bending effect stack and strengthen.The optimization of two ripples can obtain so that optimal results in the given application to be provided by calculating and/or testing.
It will also be appreciated that the design field of the little bandwidth acoustic panels that has clamped edge.
Actual enforcement of the present invention roughly illustrated in illustrative mode, in the accompanying drawing:
Fig. 1 and 1A are the decomposition diagram and the partial sections of the resonance panel sound components 10 of essentially rectangular, wherein the edge of these parts 10 is clamped between opposed rectangle perimeter frame parts 11A, the 11B by nut, bolt 12A and 12B, and these perimeter frame parts 11A, 11B also can further be used to be installed on base or other parent structure.
To be expression be fixed in the partial cross section figure at another edge of the clamping of the resonance panel sound components 20 of framework 21/fixing with the edge to Fig. 2 by binding agent 22;
Fig. 3 and 3A are part perspective view and the partial cross section figure that forms the plasticity injection molded 35 of a wall spare, this wall spare has the ribs 36 that intersects with square boundary 31, this borderline region 31 is as the effective restriction edge of panel area 30 on the sound, and this borderline region 31 also rib that exceeds at the edge by strengthening guidance panel district 30 forms;
Fig. 4 is the resonance panel sound components 40 part perspective views that stretch on framework 41 and the edge is clamped by clamping frames parts 42 on every side;
Fig. 4 A is the partial cross sectional view of the embodiment of Fig. 4;
Fig. 4 B is the partial cross sectional view that is similar to Fig. 4 A that another embodiment of panel sound components is extended in resonance;
Fig. 5 A, 5B are respectively the curves of frequency response of each resonance surface plate member of expression A4 and A5 size, wherein the panel at the edge that clamps of thick line track representative and on behalf of freedom or elastic edge, the fine rule track hang the panel that holds.
Fig. 6 A, 6B and 7A, 7B and 8A and 8B be for the panel component at the edge that clamps selected shape than the time mechanical impedance with respect to the curve representation of frequency;
Fig. 9 A, 9B, 9C are the curve representations for contrary (inverse) mean square deviation of the relevant smoothing of the position of transducer apparatus;
Figure 10 is the calculated curve of 1/4 panel mechanical impedance of the panel component of a clamped edge;
Figure 11 is the curve representation for the difformity ratio of the panel of clamped edge;
Figure 12 A-H is than the 1/4 panel mechanical impedance curve of measuring for difformity;
Figure 13 A-H is the related sound curve of output that is suitable for a reference value;
Figure 14 drawn for the inverse probability mean square deviation of difformity ratio maximum;
Figure 15 A-J be for the clamped edge panel component have 1: 3 shape than the time the combination polar diagram of voice output of Hyporesonance mode;
Figure 16 A-E is the voice output power comparison curves for particular panel structures different on size and/or rigidity.
Referring to Fig. 1 and 2, sound components can be and be represented as essentially rectangular, and can have and in WO97/09842, think the preferred shape ratio, have useful potentiality although wideer shape shows in general target (objective) than scope, and in parts, obtain high modal density and uniform modal distribution.
Fig. 4 and 4A express an embodiment of resonance sound parts 40, and it is being stretched on rectangle perimeter frame 41 and clamped framework 42 is clamped on the rectangle perimeter frame so that sound components is held in place.Tension force is applied in parts 40 in the direction of arrow F.Another kind of situation is, shown in Fig. 4 B, clamping frames 42 device 43 that can be tensioned replaces, and for example tensioning apparatus 43 comprises the tensioning spring 44 on the framework 45, and this tensioning apparatus is fixed in the edge of sound components so that parts are stretching on the rectangle perimeter frame.
Vibration exciter, the sort of vibration exciter of for example in WO97/09842, describing, can be placed on the sound components among the embodiment of Fig. 4,4A and 4B, produce voice output with excitation resonance in sound components, thereby sound components can be used as loud speaker or loudspeaker drive unit.For clear, these vibration exciters are not shown in Fig. 4,4A and 4B.
The material that the strong restriction of face plate edge or clamping make it possible to use rigidity low relatively (comparing) with the general application of the panel of edge fundamental freedom, it can be helpful by the basic bending model frequency that reduces panel, comprises even below horizontal can both the application of the panel that is actually used in general harder edge fundamental freedom (although in fact having lost the free edge mode of low-limit frequency in the panel in whole clamping).For example, the hardness range that is used for the concrete instance of the sort of free edge panel that WO97/09842 describes can be at 0.1 to 50Nm the order of magnitude, the hardness of the clamped edge panel of identical general classes can be hanged down the amplitude of at least one the order of magnitude, even is low to moderate 0.001Nm.And the scope of the superficial density of the described concrete instance of free edge panel can be 100 to 1000g/m
2, the superficial density of clamped edge panel only is its sub-fraction, even is low to moderate 25g/m
2It should be understood that stone and/or closeer material can be used for acoustic panels here by firm edge limitation or clamping, at least under the situation that does not require the low-limit frequency performance.This application comprises tweeter, alarm, ultrasonic regenerator.
Use the panel material of relatively low stiffness can cause higher coincidence frequency, for example on normal sonic-frequency band, this can improve the uniformity from the audio direction of resonance Speaker panel.And the panel of lower rigidity can strengthen the modal density in the low range effectively, therefore improves sound quality.
The useful change of carrying out for the restriction/clamping on whole as shown in the figure surrounding edge/border, comprise any effectively remarkable restriction/clamping of littler degree, for the panel component/effective coverage that is roughly rectangle, it can be to have omitted the restriction shown in other three side in a side; Or the restriction shown in other both sides has been omitted in parallel both sides usually.
The audio emission parts here can encourage with any mode of advising among the WO97/09842, for example by the dynamo-electric activator device of at least one inertia.These or each activator device can be provided to any suitable geometric position stimulated emission parts on the zone of sound components, this or come to determine according to the principle among the WO97/09842 or according to mechanical impedance analysis among the PCT/GB99/00404 or experiment.For clear, this vibration exciter is omitted from Fig. 1.
For applicable exciter kind, can be with reference to WO97/09842, and the location of these exciters can be determined according to the principle identical with the principle of instructing among WO97/09842 and/or the PCT/GB99/00404, compares with WO97/09842, and difference is can be used for actual position.
To as or be positioned at active acoustic apparatus, particularly some useful researchs of the resonance surface plate member of the whole edge clamping of loud speaker, at first be disclosed in pending trial PCT application PCT/GB99/00404 and relevant with its Figure 11 to 16 together, this application proposed on February 9th, 1999; These figure here are repeated to occur, respectively as Fig. 6 to 11.Yes based on the analysis that the parameter that relates to the power transmission is carried out in these researchs, especially the smoothness of special relevant with mechanical impedance input power; And especially, particularly compare and the transducer position on the basis of pro rata coordinate for the shape that is the panel component of essentially rectangular at least to the influence of available-optimization transducer position and panel component shape.Like this, Fig. 6 A, 6B and 7A, 7B and 8A, 8B are that mechanical impedance is the curve representation of the frequency of isotropic panel component for having selected shape ratio and bending stiffness, these curves are attended by the curve representation of Fig. 9 A, 9B and 9C, these curves are to be used for the level and smooth mechanical impedance measured by the contrary mean square deviation of standard, are used for the location of transducer position likely especially.The preferred shape of accurate Calculation than 1.160,1.341 and 1.643 and preferred transducer position coordinate (0.437,0.414), (0.385,0.387), (0.409,0.439) of same accurate Calculation showed respectively together.Figure 10 be for shape than being the 1/4 panel mechanical impedance curve that calculated in 1.16 o'clock, and expressed the base region in the zone that is hopeful to be used for transducer position, or even two such separated regions (diagonal district).Figure 11 provides the comparison of this preferred clamped edge shape ratio and transducer position, also comprises for shape than the situation that is 1.138.
Here the further research of being done is based on the actual measurement for mechanical input power, and what relate to shape ratio with increase is the resonance surface plate member of rectangle substantially; And in various situations, make the match of frequency response for the reference value of ten times of minimum effective resonance mode frequencies or straight straight line.1/4 panel equivalent curve of the mean square deviation inverse of this match provides in Figure 12 A-H, comprise and be used to equal or approach the situation of above-mentioned shape than (Figure 12 A, 12B and 12D), corresponding Figure 13 A-H is used for the straight straight-line frequency of match respectively, and low haze/shade is represented the most feasible transducer position and entered with the discontinuity zone of higher shape than the feasibility of indication.
These are further studied and extend to the shape ratio is that 1: 4 such height is to be worth, and perhaps especially sets up the aspect by square or near the feasibility of square beginning.At least we can say, this to before us concerning having for bending wave vibration the resonance surface plate member at edge is carried out freely basically the instructive work and instruction background, be unexpected.Same, herein from Fig. 5 A, 5B determine for the unexpected increase of shape than 1.41 o'clock operating powers, further be confirmed as with present other shape of studying than linking up.More unexpected, significantly reduce shape and be given in the average headway that sound is used favourable resonance mode frequency, for further thinking over and analysis has provided reason than critical value.Following result provides according to the beam flow theory of simplifying, and the resonance surface plate member is roughly rectangle, and the bending stiffness of resonance surface plate member is essentially isotropism.
Generally speaking, from before work/instruction confirm, that is to say, for the panel component of free edge basically, minimum resonance mode frequency by the size decision of long limit is best, and and corresponding to the minor face size of the higher resonance mode frequency of the next one together, provide the sequence separately of the resonance mode frequency that is mutually related higher.These sequences numerically are in interleaved relation with each other substantially.In fact, for the panel of free edge basically, big shape is than the second level (or higher) that can cause directly based on the panel component resonance mode frequency of long limit size, be lower than simultaneously the first order then based on the minor face size.Thereby band gap is greatly to the sound performance that can not reach the satisfaction of dependence bending wave action when really being implemented in related this low frequency.
In contrast, resonance surface plate member for the clamping of complete edge, in fact first effective resonance mode frequency requires by first resonance mode contribution based on bond length, the axle x that just is parallel to the limit, two sequences of y (fx1, fx2: ... fxn) with (fy1, first combined modality of plane vibration effect fy2:...fym), shown in resonance mode spectrum equation:
The effect of this orthogonality relation promptly, big shape is a series of very close resonance mode frequencies than producing, these frequencies are based on the contribution of inferior high-order in those sequences relevant with long limit, secondly are the contributions of inferior high-order in the sequence relevant with minor face.Figure 14 relation of maximum power mean square deviation inverse of having drawn with respect to the shape ratio, and show that with shape than increasing, power evenness (greater than minimum effective resonance mode) increases, and reaches peak value at about 1: 3 place.Effectively, for the big shape of the affined parts in the edge resonance mode frequency more close, yet otherwise be applicable to the panel of the relative free edge in the document WO 97/09842 than having.
Certainly, the effect that this result in no case detracts the useful of the acoustic apparatus that uses the resonance surface plate member that littler shape clamps than, whole edge and has, it also can be applied to operate from the required acoustic apparatus that begins as the interleave resonance mode frequency that above-mentioned analysis indicated the PCT/GB99/00404 fully.
But, bigger designability is obviously arranged here.In the required application of any specific situation and the acoustic apparatus here; for given bending stiffness or shape ratio; the specific frequency spectrum of resonance mode frequency will compare and significant change along with shape, and make one's options based on result that calculated, measurable or that feel usually for acoustic apparatus performances needs or acceptable.
Another correlative factor is determined and has studied, promptly relate to sound effect and performance axle and/or that relate to attitude, for the gap of these factors be significantly and when designing specific acoustic apparatus be for specific application useful/effectively, especially especially useful under the essential really or unnecessary situation of this gap/effectively, perhaps preferred or more acceptable particular combinations of these factors be useful/effectively.Figure 15 A-J is respectively that the shape ratio is 1: 3 the combination polar diagram of a resonance surface plate member for than the Hyporesonance model frequency time, in all cases, expression is (solid line) and vertical (dotted line) plane laterally, promptly represents with level or vertical longer size.Usually, as institute's phase, the emission form is visibly different, and is more level and smooth usually in the face of smaller length, more disperse in the face of length.Design option comprises the acceptability of the upper frequency of minimum resonance mode, and it directly depends on the shape ratio for any specific panel component structure; Be included in the disalignment visibly different direction-sense acceptability of vibration of plate member upward; Therefore use the orientation of panel component or the relevant selection of attitude in the power smoothness difference of the corresponding surface of emission; The not power smoothness in the coplanar and or total power smoothness and horizontal/vertical or the similitude of the middle response of orientation/height face (azimuth/elevation planes) or effective balance of others.
The panel component of Figure 16 A is included in the thick black glass of the 0.05mm top layer on the thick aluminium honeycomb of 4mm, and the result obtains isotropic basically bending stiffness of 12.26 Newton meters, the mass density of 0.76 Kilograms Per Square Meter and the coincidence frequency of 4.6kHz.The panel component of Figure 16 B is included in the thick black glass of the 0.102mm top layer on the thick Rohacell core of 1.8mm, and the result obtains isotropic basically bending stiffness of 2.47 Newton meters, the mass density of 0.60 Kilograms Per Square Meter and the coincidence frequency of 9.1kHz.The panel component of Figure 16 C is included in the thick Melinext of 0.05mm on the thick Rohacell core of 1.5mm
TMThe top layer, the result obtains isotropic basically bending stiffness of 0.32 Newton meter, the mass density of 0.35 Kilograms Per Square Meter and the coincidence frequency of 19.2kHz.These panels all have between 1.13 to 1.14 similar shapes than and with the similar exciter driving of 13mm effective diameter and 8 ohm of input impedance.The sound power of each panel component is when measuring, and all face plate edge all are free vibration for the resonance bending wave action of panel, and all edges are all clamped resists this vibration.Figure 16 A-C is illustrated in and is clamped in the raising that realizes in the voice output power below the coincidence frequency, although not shown situation more than coincidence frequency, coincidence frequency is high more, and the beneficial effect of clamping is big more, so, only considered the lower bending stiffness of panel component.
The panel component that is used for Figure 16 D-E has the hardest identical structure, and is the same with Figure 16 A, but has the bigger size of size than 260mm * 230mm of Figure 16 A-C, promptly is respectively 360mm * 315mm and 545mm * 480mm.Here prove from coincidence frequency lowly to the minimum resonance mode frequency of the specific panel component that relates to and to clamp fully and to have produced improved voice output power again to for about 400Hz of minimal face plate member (Figure 16 A-C) and for the lower coincidence frequency of bigger or maximum panel component.It should be noted that also panel component is big more, approach sine wave more for the shape of the mode of given frequency.
The inspection measure is made up of the mechanical input power of all these panel components that drive when edge free vibration and edge clamp fully, and shows that all panel components take power much at one.
Interested is the thinking to supposing before the opposite instruction of WO97/09842: based on hoping the theory that obtains complete sine wave mid-term at unlimited panel, can not get the useful audio emission below coincidence frequency; Deferring to the instruction of WO97/09842 has clearly determined, is available in audio emission useful below the coincidence frequency on limited panel, be the part of this emission from limited panel, each part is and the strange land vibration mutually of complete Sine distribution, it mainly shows as and is used for low-limit frequency mode and is close to the excitation transducer and in the situation of the edge of free vibration, that emphasize certainly is the latter here.But, by its instruction, obviously specifically limit the ability of coming the vibration of limit flexion ripple in the edge and be coupled in air for sound beneficial effect is arranged, especially be enhanced in the following efficient of coincidence frequency.Certainly, this is to take place in a self-evident environment of voice output power, this environment must be with resonance panel component in and the sound near field in loss relevant, at least the latter is reduced significantly by its edge limitation, has eliminated the sound short circuit on every side at the such edge that stands this restriction effectively.
The raising of the coupling of sound below the coincidence frequency and air owing to those otherwise the reflection of those energy that will in the sound near field, lose look like reasonably, if only on this basis, this energy is in the bending wave vibration of the resonance mode frequency with interested range of sounds wainscot parts, and must be left acoustic energy to panel component, no matter at limited edge still at the mid portion of panel component as raising to the coupling of air.Situation more than the coincidence frequency is unaffected certainly.Certainly this all is in the scope in nearlyer step of the available resonance mode of the panel component that has edge limitation, this edge limitation is necessary, can vibrative distortion mode, this torsion mode is especially clamped effective reduction or elimination by edge limitation.
On the basis of measurement result, use relocatable/unfixed second transducer the position that is of value to second transducer to be carried out the research in a nearly step; Use inertia mass to study discontinuous edge limitation/clamping in the position of location.Mainly emphasize interactional scope and complexity between the effect in the resonance surface plate member of two transducers about the result of the position of second transducer.In fact, be used for substantially for rectangular shape and the best with resonance surface plate member of isotropic bending stiffness basically inferior to a transducer of first transducer of favourable placement represent the position be actually or near central authorities near or be close to along the position of 3/4 length that defines foursquare of the panel of placing first transducer, the quality of voice output trends towards by negative effect (although being enforceable for some application undoubtedly).The result of discontinuous restriction/clamping is being to make us interested especially aspect the transition that shows potentially useful, and this transition is near wavelength dependence that is equivalent to the bending wave (equivalence) continuous restriction/be clamped to and the panel component of considering and the bigger relevant audio bandpass filter effect in interval.
Claims (26)
1. acoustic apparatus, depending on bending wave action also can work under coincidence frequency, comprise a sound components, sound by in this sound components, forming resonance bending wave mode, it is characterized in that also comprise the device that defines this sound components at least in part, this defines device and has limited characteristic for bending wave vibration, the described device that defines is positioned on the described parts edge on every side, and along occupying at least 25% of described edge on every side continuously.
2. acoustic apparatus, comprise a sound components, sound by in this sound components, forming resonance bending wave mode, it is characterized in that, also comprise a device that defines described sound components at least in part, this defines device bending wave vibration is had limited characteristic, transducer apparatus position on described sound components by with reference to and consider that this device that defines determines, the described device that defines is positioned on the described sound components edge on every side, and along occupying at least 25% of described edge on every side continuously.
3. according to the acoustic apparatus of claim 1 or 2, it is characterized in that define device and be used for and limit described acoustics active zone, this sound components is the part of a structure or this structure.
4. according to the acoustic apparatus of claim 1 or 2, it is characterized in that, define device and extend along the described zone of rectangle or a limit of panel component.
5. according to the acoustic apparatus of claim 4, it is characterized in that, define device and also extend along the relative parallel edges of described zone or panel component.
6. according to the acoustic apparatus of claim 1 or 2, it is characterized in that, define device and extend in the entire circumference at described zone or edge.
7. according to the acoustic apparatus of claim 1 or 2, it is characterized in that, define the integral rigidity that device obviously promotes these parts, this is effective in required acoustic operation.
8. according to the acoustic apparatus of claim 7, it is characterized in that the bending stiffness of these parts is below 5 Newton meters in described acoustics active zone.
9. acoustic apparatus according to Claim 8 is characterized in that, described bending stiffness is more than 0.001 Newton meter.
10. according to the acoustic apparatus of claim 9, it is characterized in that the superficial density of these parts is from 25g/m in described acoustics active zone
2Beginning.
11. the acoustic apparatus according to claim 1 or 2 is characterized in that, the described zone of described parts has isotropic bending stiffness.
12. the acoustic apparatus according to claim 1 or 2 is characterized in that, the described zone of described parts has two-way anisotropic bending stiffness.
13. the acoustic apparatus according to claim 1 or 2 is characterized in that, the described zone of described parts has the bending stiffness that is suitable for the needed vantage point of transducer apparatus and distributes.
14. the acoustic apparatus according to claim 1 or 2 is characterized in that, described zone is a rectangle, and its bending stiffness is isotropic, and has the shape ratio between 1: 1 to 1: 1.5.
15. the acoustic apparatus according to claim 1 or 2 is characterized in that, described zone is a rectangle, and its bending stiffness is isotropic, and has the shape ratio greater than 1: 1.5.
16. the acoustic apparatus according to claim 15 is characterized in that, described shape ratio is 1: 3 or bigger.
17. the acoustic apparatus according to claim 1 or 2 is characterized in that, defines device and is used for limiting at least the resonance mode of the bending wave action that relates to distortion.
18. the acoustic apparatus according to claim 1 or 2 is characterized in that, defines the near field that device is used for reducing at least voice output and offsets.
19. the acoustic apparatus according to claim 1 or 2 is characterized in that, defines device and is used for improving voice output from the energy of the resonance bending wave action in the described zone.
20. the acoustic apparatus according to claim 1 or 2 is characterized in that, these parts are tensioned.
21. the acoustic apparatus according to claim 20 is characterized in that, these parts are tensioned in a lateral direction at two.
22. the acoustic apparatus according to claim 21 is characterized in that, tensioning equates on both direction.
23. the acoustic apparatus according to claim 22 is characterized in that, the bending stiffness of these parts in the acoustics active zone is low.
24. the acoustic apparatus according to claim 20 is characterized in that, the superficial density of these parts in the acoustics active zone is low.
25. the acoustic apparatus according to claim 1 or 2 is characterized in that, defines device and this parts one.
26. the acoustic apparatus according to claim 25 is characterized in that, defines device and this parts one molding.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9806994.1 | 1998-04-02 | ||
| GBGB9806994.1A GB9806994D0 (en) | 1998-04-02 | 1998-04-02 | Acoustic device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1296720A CN1296720A (en) | 2001-05-23 |
| CN1143593C true CN1143593C (en) | 2004-03-24 |
Family
ID=10829678
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB998046930A Expired - Lifetime CN1143593C (en) | 1998-04-02 | 1999-03-30 | Acoustic device relying on bending wave action |
Country Status (27)
| Country | Link |
|---|---|
| EP (1) | EP1068770B1 (en) |
| JP (1) | JP4258696B2 (en) |
| KR (1) | KR20010042428A (en) |
| CN (1) | CN1143593C (en) |
| AR (1) | AR018832A1 (en) |
| AT (1) | ATE294492T1 (en) |
| AU (1) | AU746216B2 (en) |
| BG (1) | BG104810A (en) |
| BR (1) | BR9909901A (en) |
| CA (1) | CA2326161A1 (en) |
| CO (1) | CO4830489A1 (en) |
| CZ (1) | CZ300065B6 (en) |
| DE (1) | DE69924990T2 (en) |
| EA (1) | EA003215B1 (en) |
| GB (2) | GB9806994D0 (en) |
| HK (1) | HK1032504A1 (en) |
| HU (1) | HUP0102859A3 (en) |
| ID (1) | ID27055A (en) |
| IL (1) | IL138312A0 (en) |
| NO (1) | NO20004921L (en) |
| NZ (1) | NZ506731A (en) |
| PL (1) | PL343115A1 (en) |
| SK (1) | SK14552000A3 (en) |
| TR (1) | TR200002878T2 (en) |
| TW (1) | TW475340B (en) |
| WO (1) | WO1999052324A1 (en) |
| ZA (1) | ZA200004746B (en) |
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| CN1930910B (en) * | 2004-03-11 | 2012-09-05 | 新型转换器有限公司 | Loudspeakers |
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| US6826285B2 (en) | 2000-08-03 | 2004-11-30 | New Transducers Limited | Bending wave loudspeaker |
| GB0018996D0 (en) * | 2000-08-03 | 2000-09-20 | New Transducers Ltd | Bending wave loudspeaker |
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| SE523321C2 (en) * | 2002-06-20 | 2004-04-13 | Covial Device Ab | Method and apparatus for sensing and indicating acoustic emission |
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-
1999
- 1999-03-30 CO CO99019187A patent/CO4830489A1/en unknown
- 1999-03-30 DE DE69924990T patent/DE69924990T2/en not_active Expired - Lifetime
- 1999-03-30 AT AT99910539T patent/ATE294492T1/en not_active IP Right Cessation
- 1999-03-30 CZ CZ20003591A patent/CZ300065B6/en not_active IP Right Cessation
- 1999-03-30 EP EP99910539A patent/EP1068770B1/en not_active Expired - Lifetime
- 1999-03-30 PL PL99343115A patent/PL343115A1/en unknown
- 1999-03-30 HU HU0102859A patent/HUP0102859A3/en unknown
- 1999-03-30 IL IL13831299A patent/IL138312A0/en unknown
- 1999-03-30 TR TR2000/02878T patent/TR200002878T2/en unknown
- 1999-03-30 SK SK1455-2000A patent/SK14552000A3/en unknown
- 1999-03-30 EA EA200001016A patent/EA003215B1/en not_active IP Right Cessation
- 1999-03-30 NZ NZ506731A patent/NZ506731A/en not_active IP Right Cessation
- 1999-03-30 GB GB0020986A patent/GB2350008B/en not_active Expired - Lifetime
- 1999-03-30 ID IDW20001946A patent/ID27055A/en unknown
- 1999-03-30 KR KR1020007011016A patent/KR20010042428A/en active IP Right Grant
- 1999-03-30 CA CA002326161A patent/CA2326161A1/en not_active Abandoned
- 1999-03-30 BR BR9909901-2A patent/BR9909901A/en not_active IP Right Cessation
- 1999-03-30 AU AU29471/99A patent/AU746216B2/en not_active Ceased
- 1999-03-30 JP JP2000542953A patent/JP4258696B2/en not_active Expired - Lifetime
- 1999-03-30 WO PCT/GB1999/000848 patent/WO1999052324A1/en active IP Right Grant
- 1999-03-30 CN CNB998046930A patent/CN1143593C/en not_active Expired - Lifetime
- 1999-03-31 AR ARP990101512A patent/AR018832A1/en not_active Application Discontinuation
- 1999-04-02 TW TW088105320A patent/TW475340B/en not_active IP Right Cessation
-
2000
- 2000-09-08 ZA ZA200004746A patent/ZA200004746B/en unknown
- 2000-09-29 NO NO20004921A patent/NO20004921L/en unknown
- 2000-09-29 BG BG104810A patent/BG104810A/en unknown
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8054194B2 (en) | 2003-02-10 | 2011-11-08 | Autronic Plastics, Inc. | System and method for verifying a security status of a lockable container |
| CN1930910B (en) * | 2004-03-11 | 2012-09-05 | 新型转换器有限公司 | Loudspeakers |
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Address after: Cambridge County Patentee after: NVF Technology Co.,Ltd. Address before: Cambridge County Patentee before: HIWAVE TECHNOLOGIES (UK) LTD. Address after: Cambridge County Patentee after: HIWAVE TECHNOLOGIES (UK) LTD. Address before: Cambridge County Patentee before: NEW TRANSDUCERS Ltd. |
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