CN100433937C

CN100433937C - Loudspeakers

Info

Publication number: CN100433937C
Application number: CNB018173284A
Authority: CN
Inventors: 克里斯廷·埃利斯; 尼古拉斯·P·R·希尔
Original assignee: New Transducers Ltd
Current assignee: NVF Tech Ltd
Priority date: 2000-11-30
Filing date: 2001-11-14
Publication date: 2008-11-12
Anticipated expiration: 2021-11-14
Also published as: WO2002045460A3; JP2004515178A; HK1054483A1; EP1340407A2; TW515220B; MXPA03004732A; AU2002223800A1; AR031425A1; CN1554209A; BR0115753A; CZ20031501A3; DE60132357T2; DE60132357D1; GB0029098D0; EP1340407B1; WO2002045460A2

Abstract

A loudspeaker comprising a panel-form acoustic member adapted for operation as a bending wave radiator and an electrodynamic moving coil transducer having a voice coil mounted to the acoustic member to excite bending wave vibration in the acoustic member. The junction between the voice coil and the acoustic member is of sufficient length in relation to the size of the acoustic member to represent a line drive such that the acoustic member has a mechanical impedance which has a rising trend with bending wave frequency.

Description

Loud speaker

Technical field

The present invention relates to bending wave panel loudspeaker, this kind resonance bending wave panel loudspeaker of being demonstrated for example by WO 97/09842, and relate to the CD-ROM drive motor of this loud speaker.

Background technology

When making the vibration transducer of electrical bending corrugated plate loud speaker, it is moving coil, voice loop size of being considered at present and quality towards the voice loop system that uses minor diameter and little quality, are the size of the high pitch loudspeaker coil of known piston type loud speaker on the typical case all.In some applications, for example by driving bending wave panel or the barrier film shown in the WO 98/39947, it is for example by centre-driven, so its piston type and bending-type action simultaneously, this minor diameter voice loop can cause Power Processing and the relevant problem of skew.

For this minor diameter voice loop, this driving point impedance (Zm) is similar to a panel that drives on a single point.When frequency increased, Zm vibrated with modal structure, but on average constant, and be similar to by following formula given unlimited panel numerical value:

Zm = 8 \sqrt{Bμ}

The result of one given voice loop quality (Mc) has a high-frequency limitations (f (b)), and the rising impedance of this quality surpasses this constant driving point impedance when being higher than it.This frequency as shown in the formula:

f (b) = \frac{Zm}{2 πMc}

Therefore the voice loop quality on known bending wave bent plate promptly remains on low numerical value according to following formula.

This tangible mode is that increase Zm or reduction Mc remain on the high reversal frequency (turnover frequency) in this sound wave band.The voice loop diameter only once increased a little, only was found to this unit cover then, the drum pattern, and resonating becomes to take as the leading factor, and causes too early stopping (roll-off).

Other factor that can be unfavorable for the low quality voice loop of piston type driving panel is sensitiveness and frequency range.In order to keep a desirable low frequency bandwidth in the volume of desirability sealing, this diaphragm quality needs to improve.To keep high susceptibility, this B1 force factor will need to be height.High B1 driver increases this B1 product according to the pitch of the laps number usually, therefore increases the voice loop quality.

Another direction is to use hanging vibration excitation device design, and it increases this B1 product according to this magnet, and it is low keeping the voice loop quality with this.This has used a 25mm voice loop diameter to follow the trail of, and has the rigidity of increase on this drive point.But still can handle and skew by power-limiting.

Learnt that WO 97/09842 can provide a surface plate loud speaker, it is in the running of low frequency piston type, and at the high frequency low-resonance.It also learns patent US-A-4, and 532,383 provide the loud speaker with a moving coil transducer and barrier film, and it is similar diameter, and this voice loop is configured to drive this barrier film around it.

Summary of the invention

The invention provides a kind of loud speaker, it comprises: the acoustic assembly of the flat type of a circle is used for as a bending wave radiator and as the gamut device; One electronic moving coil transducer, it has a voice loop, be installed to this acoustic assembly and with the concentric bending wave vibration that excites in this acoustic assembly of this acoustic assembly, and move this acoustic assembly with one-piece pattern; One framework, its part is around this acoustic assembly, and another part supports this electrodynamic transducer; And be used for being connected suspension apparatus between this acoustic assembly and this framework, so that elasticity is suspended this acoustic assembly in midair on this framework; Wherein the face that connects between this voice loop and this acoustic assembly is for circular, the enough length that has with respect to the size of this acoustic assembly is used as a gleam of driver, make this acoustic assembly have a mechanical impedance, this mechanical impedance has the ascendant trend with the bending wave frequency; The position that connects face between this voice loop and this acoustic assembly is to be positioned at or near the nodal circle of second resonance of this acoustic assembly, to be transformed into resonance bending wave behavior in higher-frequency smoothly to reach by the mass motion at low frequency.

According to the present invention, it provides a kind of loud speaker, it comprises a panel form acoustic assembly, it is as a bending wave irradiator, an and electronic moving coil transducer, it has a voice loop and is installed to this acoustic assembly and comes to excite bending wave vibration in this acoustic assembly, wherein this between this voice loop and this acoustic assembly connects mask has with respect to the sufficient length of the size of this acoustic assembly and represents a gleam of driver, make this acoustic assembly have a mechanical impedance, it on average rises with the bending wave frequency.The face that connects of this voice loop and this barrier film can be circle, and this connects face and can be continuous in fact.

The voice loop of sufficient length connects face and connects its diameter under the planar condition for this length wherein or a circle in this article, equal at the face that connects by this defined or by this voice loop around the part of this acoustic assembly in the length of at least one bending wave, and be the highest operation frequency at this loud speaker.

The strength that the mechanical impedance of one panel equals to apply at a single point is for putting the ratio of resulting speed at this.Wherein this panel is to be driven by the strength of moving on a line, and this effective mechanical impedance is the ratio in the whole strength that applies on this line average resultant speed on for the length at this line.In this explanation and claim, the use of this noun mechanical impedance is this ratio that is used to describe two kinds of drive arrangements.

It will recognize that for some drive plates or barrier film, it is only for having the unlimited barrier film of a real constant Zm.One limited barrier film has a Zm, and it vibrates around this unlimited barrier film numerical value.Similarly,, will vibrate, rise but will on average go up with frequency with modal structure by the mechanical impedance that a big regional voice loop on this barrier film is seen.

This acoustic assembly by this voice loop around part can have with this voice loop outside the different thickness of acoustic assembly part.

This transducer is configurable to move this acoustic assembly with whole subject mode simultaneously, and applies the bending wave energy to this acoustic assembly.The size of the face that connects between this voice loop and this acoustic assembly, shape and position can be adjusted with respect to the modal distribution of this barrier film or acoustic assembly, to reach in low frequency be transformed into the resonance bending wave behavior under upper frequency level and smooth by molar behavior.For example, under the situation of a circular diaphragm, be driven usually, this second resonance can cause the scrambling in this output.By a circular drives line, but effective girth opsition dependent of this drive wire and size Selection are positioned at or approach the nodal circle of this second resonance.In this literary composition, this first resonance is this integral body or piston equivalence resonance.By coupling or near the nodal circle of this second resonance, its effect can reduce, and this pattern is by faint or drive.Therefore this designer can adjust this driving parameters cause should low piston frequency increase the mode close quarters of this second quality to this medium frequency.

Quality is carried this acoustic assembly within the diameter that can be applied to this voice loop.This acoustic assembly can be non-circular shape.The geometric center of this transducer voice loop and this acoustic assembly is common center.

One second transducer can be coupled to by this voice loop around its part within acoustic assembly, and be used for causing the high frequency bending wave activity of this part.This second transducer can deviate from the main shaft of this voice loop.

Coupling device can be used to fix this voice loop to this acoustic assembly, and this coupling device has the footprint of non-circular shape.

By this voice loop around the part of the comparable acoustic assembly outside this voice loop of part of this acoustic assembly want hard.The flexural rigidity of this acoustic assembly can be anisotropic.Flexible or the depression of this acoustic assembly, or formation increases its flexural rigidity in addition.

This loud speaker can comprise a framework, and it has the part around this acoustic assembly, reaches another and supports the part of this electrodynamic transducer, can comprise the device that is connected between this acoustic assembly and this frame part in addition, and elasticity is suspended this acoustic assembly in midair on this framework.This suspension apparatus can be connected between the border of this framework and this acoustic assembly.This elasticity suspention can be used to quality and carries this acoustic assembly.This elasticity suspention can be used to this acoustic assembly of vibration damping.This elasticity suspention can be formed to the epidermis of small part by this acoustic radiator.

This acoustic assembly can be by the front side of this acoustic energy institute radiation, and can comprise place by this voice loop around this acoustic assembly part on the sound shield device, this shade device has defined a sound cavity.

This electronic moving coil transducer can deviate from the geometric center of this acoustic assembly, and provides an anti-balance mass on this acoustic assembly.

The action of big regional voice loop can produce the distribution of an excitation mode on this barrier film, and it causes the obvious transmission on this radial axis, at least on some frequency ranges.In some applications, for example differentiation of this output sound, this has benefit, but in some applications, needs the power of off-axis.A kind of mode of improving off-axis power is the panel that excites in the bending wave vibration, its frequency near or greater than this coincidence frequency.

This coincidence frequency equals the frequency of speed of sound in the air for the bending wave speed in this flat board.On this frequency, the speed in flat board can surpass airborne speed, and this ultrasonic waves vibration can cause the off-axis radiation of strong directivity.In fact when this coincidence frequency, radiation is the transmission of direct off-axis, and it transmits angle and can move when frequency increases near the direction on this.The coincidence frequency of one flat board is determined by its flexural rigidity (B) and mass density (mu).These parameters can be changed the additional energy that can be transmitted by this bending wave vibration institute off-axis on this coincidence frequency at least to a certain degree that narrows that makes by the radial pattern that this big regional voice loop caused and be compensated.

Loud speaker of the present invention can be used to as a FR device.

Description of drawings

The present invention will illustrate graphically with the example in the appended drawing, wherein:

Figure 1 shows that the front view of a loudspeaker drive motor;

Figure 2 shows that the cross-sectional side view of the CD-ROM drive motor of Fig. 1;

Figure 3 shows that the front view of a speaker housings;

Figure 4 shows that the end view of this speaker housings;

Figure 5 shows that a frequency response;

Figure 6 shows that near the field domain bass frequencies and respond;

Fig. 7 to 9 is depicted as the front view of barrier film specific embodiment, its each all have one and replenish vibration excitation device;

Figure 10 to 13 is depicted as the front view of the further specific embodiment of barrier film;

Figure 14 shows that the perspective view of the further specific embodiment of barrier film;

Figure 15 to 18 is depicted as the cross-sectional view of the specific embodiment of barrier film;

Figure 19 to 21 be depicted as diaphragm ring around or the cross section of specific embodiment of suspention;

Shown in Figure 22 is the cross-sectional view of the specific embodiment of a speaker drive motor;

Shown in Figure 23 is the front view of a specific embodiment of barrier film;

Shown in Figure 24 is the cross-sectional view of a specific embodiment of barrier film;

Shown in Figure 25 is the pole figure that compares the response of a known piston type loud speaker and loud speaker of the present invention; And

Figure 26 and 27 is the front view that voice loop/barrier film line drives the further specific embodiment of the face that connects.

Embodiment

It shown in Fig. 1 and 2 the speaker drive motor 1 that is used for being installed to a sound panel, for example in a shell, please refer to following Fig. 3 and 4, it comprises the circular flat barrier film of rigidity light material, for example comprise the core between the epidermis that is clipped in high drawing plate material, it forms an acoustic assembly or radiator, is used for piston type simultaneously, and bends under the bending wave resonance device of upper frequency and operate.Mode according to this, drive motor of the present invention can operate as a gamut device, it is contained substantially and has the whole of sound spectrum that wide sound disperses, it similarly is not known piston type driver, its frequency band or at least its dispersion angle be subject to this diaphragm diameter in high-frequency, please refer to down Figure 25, and a bending wave driver, it is to stop in the frequency that is lower than under the 200Hz, unless a very large diaphragm size.

Generally speaking, this barrier film 2 is to support with a framework or basket 3 in the known manner, for example metallic, form an annular flange 4 at its front end, it has several fixing holes 5 at interval, can be fixed on this this framework in the speaker housings in a suitable cavity, please refer to down Fig. 3 and 4.The suspention 6 of one waveform, for example the material of rubber like is made, it is fixed to barrier film around its circumference by a binding agent, and this suspention can be clipped in this annular flange 4 by the help of a clamp ring 7, with this this barrier film can be with respect to this framework and piston type move.

This framework can support an electronic mobile coil transducer 8, moves this barrier film with being used for piston type, and be used to apply the bending wave energy to this barrier film make its resonance, for example use the mode described in the WO 97/09842.This transducer comprises a magnet assemblies 9, it is fixed in this framework, and defined an annular gap 10 concentric with this barrier film, and a voice loop and the former combination 11 be installed in and be used to move axially in this annular gap, and it is fixed in this barrier film with one heart by a coupling loop 12.In known manner commonly used, waveform suspention tripod 13 is to be fixed between this voice loop combination and this framework, to guarantee this voice loop suitably moving axially in this annular gap.

This voice loop diameter is big with respect to this bending wave length, and this effect is that a gleam of driver arrives this barrier film, but not some drivers, it has the minor diameter voice loop for the bending wave radiator of the electronic exciter of use usually.This line drive provides tangible Mechanical Driven impedance to increase for this voice loop, and this higher mechanical impedance makes the quality voice loop that this system's tolerable is quite high, and can not stop too early at high frequency.Simultaneously because the major diameter of this voice loop, its might handle this barrier film panel rigidity allow by this voice loop around diaphragm portion assign to have multiplex mode, but not single main bulging pattern has as same minor diameter voice lines.The interior section 16 of this barrier film can by this voice loop around, as shown in Figure 1, when the exterior section 17 of this barrier film is radially to extend to outside this voice loop.

Shown in Fig. 1 and 2,

little quality

14,15 is fixed to the barrier film within the voice loop diameter, with the frequency response of adjustment and/or this acoustic radiator of smoothing.This quality is not necessary forever, but needs usually.These quality are shown as the quality of dispersion, but might not disperse.Its mass range can be 0.5g to 100g, and scope basically is 2 to 20g.It can provide one or more this quality.

Fig. 1 and 2 loudspeaker drive specific embodiment be optimization, is used for a high fax loud speaker, and when being coupled to an amplifier, it has a plane voltage conversion function in whole sound wave band.With this part as the design condition of this specific embodiment, following design parameter can use.

This transducer has a big 75mm diameter voice loop, and it is installed in according to having in the low inductance motor system of a steam vent 18, and it has a bronze medal vortex flow and covers 19 on this utmost point piece or header board 20.Figure 2 shows that the cross section of the magnet ring 21 of a neodymium system, it is installed in the central authorities of a magnet circuit, and it comprises a magnetic cup 22 and this header board 20, causes the B field domain of an average 0.8T.These voice loop 11 outstanding these magnetic header boards 20 are to constitute an outstanding structure.This voice loop comprises an aluminium winding height 14.5mm, on the thick aluminum coil frame of a 0.1mm.This voice loop parameter is as follows:

Axle or bobbin diameter=75mm

Coil layer number=2

Linear diameter=0.3mm

Pitch of the laps number=71

This coupling loop 12 is used for providing a fixing interface between this voice loop and this barrier film.This overlaps this voice loop inboard.It provides a 2.5mm an overlapping good combination zone that allows between this coupler and this voice loop bobbin.This coupling loop extends the effective length 1.7mm of this voice loop, provides the ring width of 3.5mm to be coupled in this barrier film.This is to be presented at Fig. 2.The material of this coupling loop is the thermoplasticity or the thermosetting resin of class of trade, ABS for example, and its quality is 3.4g.For the combination between this voice loop and the coupler, use a heat resistance cyanogen acrylic acid (Loctite 4212).This also is used in conjunction with this coupler and this barrier film.

Dynamic parameter with this motor system of this coupling loop shows below:

Mms=11g (moving mass of this voice loop combination)

Rms=1.95Ns/m (mechanical impedance of suspention)

B1=8.1Tm (motor conversion factor)

Re=6.5ohm (the DC resistance of voice loop)

Fs=40Hz (the quality spring resonance of system)

Le=0.2mH (in the inductance factor of the voice loop of 1kHz)

Employed diaphragm material and parameter thereof are as follows:

Material=Rotrex Lite 51LS (trade name) 3.5mm (it is thermoplastic expanded that the 51LS level that 3.5mm is thick is not compressed the solid-state closed cell polypropylene acrylic acid (polymethacrylimide) of Rohacell (trade name) core, and it has glass curtain/thermoplasticity epidermis).Diameter=120mm.

System of parameters is listed in table 1

Table 1

Quality region density	M	0.35	Kg/m ²
Quality region density	M	0.35	Kg/m ²	The Poisson ratio	N	0.11
Flexural rigidity	D1	2.4	Nm	The Poisson ratio	N	0.11
Flexural rigidity	D1	2.4	Nm	Flexural rigidity	D2	1.8	Nm
Damping D	D	0.02		Flexural rigidity	D2	1.8	Nm
Damping D	D	0.02		Shearing rate in the plane	Shr	0.36
Thickness	T	3.5mm	M	Shearing rate in the plane	Shr	0.36

Modulus in shear	Gz	19M	Pa
Modulus in shear	Gz	19M	Pa	Damping Gz	D	1
Coincidence frequency	Fc	7.7	kHz	Damping Gz	D	1

In the parameter that table 1 provided, the wavelength of this panel can calculate with the highest frequency of running, i.e. 20kHz.This calculates and provides wavelength based on average flexural rigidity 2.1Nm is 28mm.Therefore this voice loop diameter is the wavelength of this highest frequency running of 2.7 times.In the bending wave loudspeaker of prior art, this first cavity resonance is corresponding to a half-wavelength of this voice loop.

The coincidence blade of this panel provides approaching or the strong voice output off-axis on coincidence frequency, as above shown in the table 1.As shown in the indicator diagram of Figure 25, wherein this fine rule or trace 45 are for having the figure of the loud speaker of a 300mm diameter barrier film, reach this thick trace 44 the piston type barrier film that is a known 250mm diameter according to the present invention.

This framework comprises an aluminum backboard 23 and supports this transducer 8, and it is to be connected to this preceding bead 4.Alan's bolt (not shown) is to be used for fixing this clamp ring 7 to this bead 4.

The pairing of being fixed in the

quality

14,15 of this barrier film is used for the first eardrum formula of inside part of this barrier film of smoothing, and it is greatly about 2kHz.

This motor drive unit parameter is as follows:

DD=14cm (diameter of radiation areas (is the center with this peripheral center))

Mms=27g (moving mass of this voice loop and barrier film combination)

Rms=2.4Ns/m (mechanical impedance of suspention)

B1=8.1Tm (motor conversion factor)

Re=6.5ohm (the DC resistance of voice loop)

Fs=33Hz (the quality spring resonance of system)

Le=0.2mH (in the inductance factor of the voice loop of 1kHz)

Fig. 3 and 4 is depicted as the speaker housings 24 of the driver element of Fig. 1 and 2, and it has a front side 25 and a side 26 that tilts.One cavity 27 is provided at this front side 25 and receives this driver element or motor 1.This shell has designed provides the planar alignment of one 17 liters volume as a maximum.This shell form is selected to destroy the inner shell standing wave, though it is not this speaker design and running institute necessity.This shell is by the construction of 18mm medium-density fiberboard (MDF) institute.This contact is by gluing (using the PVA wood glue), and rotation provides an airtight sealing.

Next the measurement for above loud speaker specific embodiment is to carry out in an anechoic room, and its microphone is positioned at 1m place (on the axle of this barrier film), output 2.83v.As shown in Figure 5, can take place inaccurately being lower than about 200Hz, be shown in Fig. 6 near the field domain measurement so show one of this low frequency usefulness for measuring.

When the specific embodiment of Fig. 1 and 2 used a single major diameter voice loop driver, it is accurate and/or extend that an excitation apparatus that replenishes can be used to improve this high frequency position, and the direction usefulness of this loud speaker.Should replenish exciter and can place on the barrier film Anywhere, so that less radiation areas to be provided.Similarly be the device of big regional piezoelectricity, can use the form of zonule or bar shaped, or littler moving coil device.This is shown in Fig. 7 to 9.In Fig. 7, it can find out that a circular piezoelectric video disc vibration excitation device 28 has been installed in the center of this barrier film 2, and the inboard of these voice loop 11 diameters.In the specific embodiment of Fig. 8, a piezoelectricity bar shaped vibration excitation device 29 has been installed on this barrier film 2, center common with it, and the position is in the diameter inboard of this voice loop 11.In Fig. 9, a circular video disc vibration excitation device 30 has been installed on the barrier film 2 of inboard of this voice loop diameter 11, but off-center.

It can find out that this voice loop moving mass expands the effect with a little for the high frequency of this loud speaker.Therefore the present invention is not limited to the voice loop of light weight.The scope of moving magnet motor system is used in this representative, and/or the quite high quality coupling loop between this voice loop combination and this barrier film, and its point that can get rid of at present at little drive area or bending wave loudspeaker drives outside the design.This can allow complicated coupler design to change this voice loop ring to other preferable shape, to improve usefulness.Triangle, the coupling loop example of square and elliptical shape are to be shown in Figure 10 to 12 respectively, and it is respectively with reference to 31 to 33.These shapes are represented the distribution of the pattern that is excited, and have therefore represented the meaning of direction.For example, as shown in figure 13, if a triangle barrier film 34 is selected, together with the rectangle coupler loop 32 with respect to this barrier film sideway swivel one angle, it can provide in the barrier film a more unusual mode pattern.This also can further improve, and axle is gone up and the frequency response of off-axis.

In the specific embodiment of Fig. 1 and 2, this voice loop diameter is 75mm.This can increase or reduce according to this design specification.If this design specification need can use a bigger voice loop promptly to be coupled to a low velocity of wave panel for distinguishing the narrower directivity of using, promptly has a very high Fc.On the contrary, wide directionality can use a less voice loop if desired, and it is under the condition of line drive.But this needs electrical high-frequency to pressurize to keep the fixation pressure in the whole sound wave band.

As above shown in Figure 13, the present invention is not limited to the round panel shape shown in the specific embodiment of Fig. 1 and 2.May be preferable for directivity and/or other shape of frequency response, because can cause different model shapes by the geometry of this panel.It can be expected at model shape more complicated in this panel, makes that the directivity in the voice output is less.Example comprises square, rectangle, and hexagon panel.

Simultaneously, as shown in figure 14, the present invention is not limited to the pure piston behavior of barrier film at low frequency, and the class eardrum behavior under low frequency.This barrier film 34 can be a large radiation panel.This can provide a kind of device of self-dividing plate, and a bipolar bass response is provided, shown in relative arrow.This face plate edge can be freedom or clamps.

The present invention is not limited to a planar separator or is limited to a homogenous material form.The profile of this barrier film and shape can be used for changing this mode behavior.For example, by this voice loop around membrane portions can be by different material construction, or use same material but thicker or thinner.Exemplary specific embodiment is shown in Figure 15 to 18.Rigidity can put on this barrier film by contoured.But variation in rigidity also tropism such as materials used realizes.Therefore in Figure 15, the interior section 16 of this barrier film 2 is to come attenuation by its lower epidermis of depression.In Figure 16, the interior section 16 of this barrier film is thickeied.In Figure 17, the interior section 16 of this barrier film 2 is thinner equably than the exterior section 17 of this barrier film.In Figure 18, the exterior section 17 of this barrier film 2 little by little reduces towards this interior section on thickness, until the left side of drawing, and can find out that by the right side of drawing it forms the crooked outline of a variable thickness.

It can find out that this diaphragm ring is around having influenced acoustic performance.This piston and mode zone all can by change this around material character change.Particularly, if quality is applied to the circumference of this barrier film, shown in label among Figure 19 36, can improve high frequency usefulness.The edge vibration damping of this barrier film can be used to control its mode behavior.This can be surface treatment or the limit form than vibration damping, and it can be by should be around footprint, shown in 37 among Figure 20.This panel epidermis, or one of them can be used to form should around, as shown in Figure 21.In this specific embodiment, this barrier film comprises a core 38, and covers the

epidermis

39,40 of this core.This lower epidermis 40 be extended form this around or suspend 6 in midair.This can provide the benefit on the cost.The low-loss that benefit also can comprise this barrier film stops.

Being used in this preferred embodiment greater than the radiation under the frequency of this coincidence frequency (fc), to widen directivity at high frequency near reaching.But repeatability can be set in arbitrary end of this frequency spectrum.Increasing this panel rigidity/this coincidence frequency of reduction should still provide the directivity of broad, and improves mode area sensitive degree.

Use and wait to barrier film, for example be about twice Fc, it will provide the lateral lobe sheet at the same position place in two planes.When using the anisotropic panel, repeatability can independently be set in the plane at interval, so that more level and smooth overall power response to be provided.

Mechanical organ for example is coupled in the quality or the voice loop of this panel, and it can provide a mechanical filter.By between this voice loop coupler and this panel, placing an interface, can revise this frequency response.Passive device electrically tilting (shelving) or amplifier translation function be tilting/and the high frequency pressurization also can be used to revise the voice output of this device.

In the specific embodiment of Fig. 1 and 2, interference sound is by this annular region radiation, and wherein this voice loop is fixed to this barrier film.This can be owing to transmission is caused in the zone of significantly penetrating with respect to airborne wavelength when high frequency.As shown in figure 22, in order to widen this directivity at high frequency, one has a little shade of empty 42 41 can be placed on the interior section 16 of this barrier film 2 in the support 43 that is installed on this framework 3, this is transformed into less radiation areas.This effect is being found out when being measured by this device rear.In the specific embodiment of Fig. 1 and 2, the exhaust outlet 18 in this motor system forms this shade cavity, and it is to consider the back radiation.

If necessary, as shown in figure 23, this voice loop 11 can place on this barrier film 2 eccentric position to improve the distribution of the resonance mode that is excited at this barrier film, and it has an anti-balance mass 35 and places and prevent vibration on this barrier film.

As shown in figure 24, this barrier film 2 does not need to be the plane, and can cave in or form in addition and increase its rigidity.This can utilize the form of the curvature that changes across this barrier film, so this rigidity becomes big towards the edge of this barrier film, as shown in the figure.The curvature of this barrier film or contoured can be assisted this barrier film of convergent-divergent, and keep fc to fix, and help this piston of smoothing and come MODAL TRANSFORMATION OF A, particularly for bigger barrier film.

In Figure 26, it is depicted as a circular diaphragm 2, it is that voice loop by a transducer drives, it is also not shown, it has the coupler 46 that a straight line constitutes, it is equal to the coupler loop 12 of the specific embodiment of Fig. 1 and 2, and it is connected between this voice loop and this barrier film, drives the face that connects so that a straight line to be provided.This coupler 46 is to arrange and be configured on the diameter of this barrier film, and its end in the opposite edges of this barrier film uniformly-spaced.

In Figure 27, it shows that it is not shown by a rectangle barrier film 2 of the voice loop driving of a transducer, and its coupler 46 with straight line formation is connected between this voice loop and this barrier film, drives the face that connects so that a straight line to be provided.This coupler 46 is to place to be eccentric in this barrier film, and with respect to the side of this barrier film at angle.

Industrial applicability

The present invention can provide an effective mode to increase the frequency frequency range of a bending wave loudspeaker with this.

Claims

1. loud speaker, it comprises: the acoustic assembly of the flat type of a circle is used for as a bending wave radiator and as the gamut device; One electronic moving coil transducer, it has a voice loop, this voice loop be installed to this acoustic assembly and with the concentric bending wave vibration that excites in this acoustic assembly of this acoustic assembly, and move this acoustic assembly with one-piece pattern; One framework, its part are around this acoustic assembly, and another part supports this electronic moving coil transducer; And be used for being connected suspension apparatus between this acoustic assembly and this framework, so that elasticity is suspended this acoustic assembly in midair on this framework; Wherein the face that connects between this voice loop and this acoustic assembly is for circular, the enough length that has with respect to the size of this acoustic assembly is used as a gleam of driver, make this acoustic assembly have a mechanical impedance, this mechanical impedance has the ascendant trend with the bending wave frequency; The position that connects face between this voice loop and this acoustic assembly is to be positioned at or near the nodal circle of second resonance of this acoustic assembly, to be transformed into resonance bending wave behavior in higher-frequency smoothly to reach by the mass motion at low frequency.

2. loud speaker as claimed in claim 1, wherein the face that connects between this voice loop and this acoustic assembly is essentially continuously.

3. loud speaker as claimed in claim 2, wherein by this voice loop around the rigidity of acoustic assembly part be different from this acoustic assembly part outside this voice loop.

4. as each described loud speaker among the claim 1-3, it is characterized in that it comprises a device and packs quality into to this acoustic assembly in the diameter of this voice loop.

5. as each described loud speaker among the claim 1-3, it is characterized in that it comprises one second transducer, its be coupled in by this voice loop around its part in acoustic assembly, and in order to cause the high frequency bending wave activity of this part.

6. loud speaker as claimed in claim 5, wherein this second transducer deviates from the axle of this voice loop.

7. as each described loud speaker among the claim 1-3, wherein this acoustic assembly by this voice loop around part harder than the part of this acoustic assembly outside this voice loop.

8. as each described loud speaker among the claim 1-3, wherein the flexural rigidity of this acoustic assembly is an anisotropic.

9. as each described loud speaker among the claim 1-3, wherein this suspension apparatus is connected between the edge of this framework and this acoustic assembly.

10. as each described loud speaker among the claim 1-3, wherein this elasticity suspention is used to pack into quality to this acoustic assembly.

11. as each described loud speaker among the claim 1-3, wherein this suspension apparatus is used for this acoustic assembly of vibration damping.

12. as each described loud speaker among the claim 1-3, wherein this suspension apparatus to the epidermis of small part by this acoustic assembly forms.

13. as each described loud speaker among the claim 1-3, wherein this acoustic assembly has a front side, gives off acoustic energy by it, and comprises the sound shield device, its be positioned at this acoustic assembly by this voice loop around this part on, this shade device defines a sound cavity.

14. as each described loud speaker among the claim 1-3, wherein this acoustic assembly is caved in or bending increases its rigidity.

15. as each described loud speaker among the claim 1-3, this acoustic assembly by frequency near or excite greater than the bending wave vibration of coincidence frequency.