CN2774059Y - Four-order bandpass speaker system with passive radiator - Google Patents

Abstract

The utility model relates to a four-order band pass speaker system with a passive radiator, which comprises a resonance box and an active speaker. The utility model is characterized in that a passive radiator is arranged on the resonance box, the passive radiator is fixed on the resonance box, a fixed position is sealed and the passive radiator and the resonance box are formed into a sealed whole body. The utility model having large radiation area reduces the velocity of air vibration under the condition of the same output sound pressure, and the phenomenon of low-frequency radiating distortion is improved; the passive radiator is used for separating the resonance box from outside air, the influence of the normal mode of sound waves in the resonance box on the sound radiation of the system is effectively restrained, and the non-linear distortion of the system is effectively reduced.

Description

Fourth-order band-pass with passive radiator

Technical field

The utility model relates to a kind of speaker system that can carry out electric energy and acoustic energy conversion, exactly, relates to a kind of fourth-order band-pass type speaker system of utilizing the auxiliary low frequency radiation of passive radiator.

Background technology

The speaker system acoustic construction of traditional fourth-order band-pass formula is by the active loud speaker as shown in Figure 1, forward and backward resonance box, and the phase-reversing tube three parts are formed.After the vibrating membrane of loud speaker is driven, produce vibration, and by with resonance box in the coupling of air, make air generation vibration in the resonance box, air and the coupling of phase-reversing tube be to the space radiation sound wave in the case, owing to the acoustic resonance in parallel system that preceding resonance box and phase-reversing tube are formed, has the acoustic characteristic of low pass, add upper speaker and form high way system, thereby realize the response of fourth-order band-pass type with the back resonance box.Its acoustic analog line map as shown in Figure 2, in the accompanying drawing 2, Pg is the equivalent sound potential source, Ma is the equivalent sound quality of active loud speaker, Ca is that the equivalent sound of initiatively loud speaker is suitable, and Ra is the equivalent acoustic resistance of active loud speaker, and Cbf is that the equivalent sound of preceding resonance box is suitable, Mp is the equivalent sound quality of phase-reversing tube, and Cbr is that the equivalent sound of back resonance box is suitable.Analyze accompanying drawing two, the pressure frequency response function that can draw this system is:

$P_v=\frac{\mathrm{\ρ}{P}_g}{4\mathrm{\πr}{M}_a}\left|G_v\left(\mathrm{jw}\right)\right|$

$G_v\left(\mathrm{jw}\right)=\frac{\frac{{\left(\mathrm{jw}\right)}^2}{{{\mathrm{<figure-callout\; id="2"\; label="W\; bs"\; filenames="Y20052005398900121.png,Y20052005398900122.png"\; state="\{\{state\}\}">W</figure-callout>}}_{\mathrm{bs}}}^2}}{1+\frac{\mathrm{jw}}{(1+\mathrm{\&alpha;})W_s{Q}_t}+{\left(\mathrm{jw}\right)}^2(\frac{1}{(1+\mathrm{\&alpha;}){{\mathrm{<figure-callout\; id="2"\; label="W\; s"\; filenames="Y20052005398900121.png,Y20052005398900122.png"\; state="\{\{state\}\}">W</figure-callout>}}_s}^2}+\frac{1+\mathrm{\&beta;}}{\mathrm{\&beta;}{W_p}^2})+\frac{{\left(\mathrm{jw}\right)}^3}{{W_p}^2(1+\mathrm{\&alpha;})W_s{Q}_t}+\frac{{\left(\mathrm{jw}\right)}^4}{(1+\mathrm{\&alpha;}){W_p}^2{W_s}^2}}$

Wherein: $\mathrm{\&alpha;}=\frac{C_a}{C_{\mathrm{br}}};C_{\mathrm{ab}}=\frac{C_a}{1+\mathrm{\&alpha;}};C_{\mathrm{bf}}=\mathrm{\&beta;}{C}_{\mathrm{ab}};W_s=\frac{1}{\sqrt{M_a{C}_a}};Q_t=\frac{W_s{M}_a}{R_a};W_p=\frac{1}{\sqrt{M_p{C}_{\mathrm{bf}}}};$

Its frequency response is typical fourth-order band-pass type response characteristic as can be seen, as the response characteristic or the respond style that will obtain to expect, then can determine box body parameter and phase-reversing tube size and loud speaker parameter according to the parametric equation of system function.

The tuned frequency of phase-reversing tube and resonance box coupling has determined the bound of system responses, for given speaker system, and tuned frequency F _BBe certain, the volume of resonance box also is certain, by following formula:

$F_B=1/2\mathrm{\&pi;}\sqrt{M_p{C}_b}$ ----------Mp is the phase-reversing tube acoustic mass, and Cb is that the resonance box equivalent sound is suitable,

M _p=ρ L/S _p---------------L is a phase-reversing tube length, and Sp is a phase-reversing tube equivalence swept area,

P=(ρ f/2r) U _p-----------P is a sound radiation pressure, and Up is a volume of air speed,

U _p=V _pS _p---------------Vp is the air velocity in the pipe,

As can be seen, improve the low frequency radiation acoustic pressure, then must guarantee or increase the volume of air speed of transmitting in the pipe, and volume of air speed is the sectional area product of inner air tube vibration velocity and phase-reversing tube, because the sectional area value of phase-reversing tube has certain limitation (common effective radiating area much smaller than the active loud speaker), so, improve the low frequency radiation acoustic pressure, will cause the air vibration speed in the phase-reversing tube very high, this will inevitably bring the windage noise; Therefore; we do not wish that air vibration speed is too big; on the contrary; hope descends in the situation that guarantees acoustic pressure output and hangs down the air vibration velocity; thereby the reduction low-frequency distortion so then must increase the phase-reversing tube size, will inevitably cause tube length to become very long; the length and the area of pipe are inversely proportional to, this structurally regular meeting run into certain difficulty (especially obvious in the small size loudspeaker enclosure).On the other hand, the air of this System cabine inside and outside directly is communicated with by phase-reversing tube, so the influence of sound wave normal-mode is just inevitable in the case, shows that the nonlinear distortion of system is bigger.

Summary of the invention

The purpose of this utility model provides the fourth-order band-pass that always has passive radiator, this system utilizes passive radiator to replace phase-reversing tube in traditional fourth-order band-pass formula speaker system, excellent performance, low distortion, and convenient feasible aspect the structure installation.

The technical solution of the utility model is:

A kind of fourth-order band-pass with passive radiator, comprise resonance box, the active loud speaker, it is characterized in that: on resonance box, install and be provided with passive radiator, passive radiator is fixed on the resonance box, and, make passive radiator become the integral body of sealing with the resonance box-shaped with bearing's sealing.After initiatively loud speaker is driven, produce vibration and by with resonance box in the coupling of air, make air generation vibration in the resonance box, air and usefulness are seal-installed on the coupling of the passive radiator on the resonance box in the resonance box, cause passive radiator to do the piston vibration, to the space radiation sound wave, thereby realize the fourth-order band-pass response.

Described active loud speaker is traditional direct radiator type electrodynamic loudspeaker, the particular location of its installation is on the middle dividing plate of resonance box front and back cavity, after being driven, difference is the cavity radiative acoustic wave forwards, backwards, it is installed must be firmly, mechanical oscillation can not appear, and cotton with the sealing of dividing plate junction cushioning, as the EVA cotton.

Described resonance box is made up of former and later two resonance boxes, and on the resonance box, two resonance boxes were by initiatively loud speaker connection before described passive radiator was installed on, and the tank material of resonance box must select firm difficult vibrations material to make the sheet material as MDF, requires sealing.

Described passive radiator is made by composite material, is connected the vibration sounding device of a plane or the conical surface by the good ring of elasticity; Ring must have good elasticity, is difficult for producing inelastic deformation simultaneously; The vibration sounding device must possess enough rigidity, can not produce deformation during with the assurance vibration, vibrates to be piston vibration.

Above-mentioned passive radiator, its concrete structure is: the centre is the vibration sounding device, and this vibration sounding device is slab construction or pyramidal structure, and the outer rim of vibration sounding device has ring, ring is to being externally connected with support, and the vibration sounding device is connected on the resonance box by support.

The utility model adopts passive radiator to replace traditional pipe of falling the case, and swept area is big, exports on an equal basis under the acoustic pressure situation, has reduced air vibration speed, and has improved the low frequency radiation distortion, and the system that shows significantly reduces doing low frequency playback time windage noise; The adjustment of the major parameter of passive radiator and physical dimension do not have inevitable relation, and the physical dimension degree of freedom compares higher, therefore have bigger flexibility on structural design, are particularly suitable for the design of small-sized sound system; Simultaneously, passive radiator separates resonance box and outside air, can effectively suppress the influence of the interior sound wave normal-mode of resonance box to system's acoustic radiation, effectively reduces the nonlinear distortion of system.

Description of drawings

The speaker system acoustic construction figure of the fourth-order band-pass formula that Fig. 1 is traditional,

The speaker system acoustic analog line map of the fourth-order band-pass formula that Fig. 2 is traditional,

Fig. 3 acoustic construction schematic diagram of the present utility model,

Fig. 4 acoustic analog line map of the present utility model,

Fig. 5 is the structural representation of passive radiator,

Fig. 6 is the side schematic view of passive radiator.

Embodiment

Further introduce architectural feature of the present utility model and enforcement below in conjunction with accompanying drawing:

Acoustic construction of the present utility model and scheme of installation are as shown in Figure 3, the fourth-order band-pass formula speaker system that the utility model is implemented with passive radiator, comprise resonance box, the active loud speaker, it is characterized in that: on resonance box, install and be provided with passive radiator, passive radiator is fixed on the resonance box, and with bearing's sealing, makes passive radiator become the integral body of sealing with the resonance box-shaped.

Wherein, initiatively loud speaker is traditional direct radiator type electrodynamic loudspeaker, the particular location of its installation is on the middle dividing plate of resonance box front and back cavity, after being driven, difference is the cavity radiative acoustic wave forwards, backwards, it is installed and must firmly mechanical oscillation can not occur, and cotton with dividing plate junction cushioning EVA sealing.

Resonance box is made up of former and later two resonance boxes, and on the resonance box, two resonance boxes were by initiatively loud speaker connection before above-mentioned passive radiator was installed on, and the tank material of resonance box must select firm difficult vibrations material to make the sheet material as MDF, and requires sealing.

In conjunction with Fig. 5, Fig. 6, passive radiator is made by composite material, is specifically connected the vibration sounding device 1 on a plane by the good ring 2 of elasticity; The outer rim of vibration sounding device 1 has ring 2, and ring 2 is to being externally connected with support 3, and vibration sounding device 1 is connected on the resonance box by support 3.Ring 2 must have good elasticity, is difficult for producing inelastic deformation simultaneously; Vibration sounding device 1 must possess enough rigidity, can not produce deformation during with the assurance vibration, and simultaneously, passive radiator and preceding resonance box fixed position make whole system airtight by screw and glue fixing seal.

Passive radiator can separate the air inside and outside the case as can be seen, can effectively suppress the influence of the interior sound wave normal-mode of case to system's acoustic radiation, effectively reduces the nonlinear distortion of system.

According to the acoustic analog principle acoustic analog line map of the present utility model that can draw, as shown in Figure 4.Wherein Pg is the equivalent sound potential source, Ma is the equivalent sound quality of active loud speaker, Ca is that the equivalent sound of initiatively loud speaker is suitable, Ra is the equivalent acoustic resistance of active loud speaker, Cbf is that the equivalent sound of preceding resonance box is suitable, Mp is the equivalent sound quality of passive radiator, and Cp is that the equivalent sound of passive radiator is suitable, and Cbr is that the equivalent sound of back resonance box is suitable.The pressure frequency response function that can derive the radiation of sound system of the present utility model institute thus is as follows:

$P_{\mathrm{pr}}=\frac{\mathrm{\&rho;}{P}_g}{4\mathrm{\&pi;r}{M}_a}\left|G_{\mathrm{pr}}\left(\mathrm{jw}\right)\right|$

$C_{\mathrm{pr}}\left(s\right)=\frac{{\left(\frac{\mathrm{jw}}{W_0}\right)}^2\frac{W_p{C}_p}{W_{\mathrm{bs}}\sqrt{(C_p+C_{\mathrm{ab}}+C_{\mathrm{bf}})C_{\mathrm{bf}}}}}{\left\{\begin{array}{c}1+s\sqrt{\frac{W_p}{W_{\mathrm{bs}}}}\frac{(C_p+C_{\mathrm{bf}})}{Q_{\mathrm{bt}}\sqrt[4]{C_{\mathrm{bf}}{(C_p+C_{\mathrm{ab}}+C_{\mathrm{bf}})}^3}}+s^3\sqrt{\frac{W_p}{W_{\mathrm{bs}}}}\frac{\sqrt[4]{C_{\mathrm{bf}}}}{Q_{\mathrm{bt}}\sqrt[4]{C_{\mathrm{bf}}{(C_p+C_{\mathrm{ab}}+C_{\mathrm{bf}})}^3}}+s^4\\ +s^2[\frac{W_p}{W_{\mathrm{bs}}}\frac{C_p+C_{\mathrm{bf}}}{\sqrt{(C_p+C_{\mathrm{ab}}+C_{\mathrm{bf}})C_{\mathrm{bf}}}}+\frac{W_{\mathrm{bs}}}{W_p}\frac{C_{\mathrm{bf}}+C_{\mathrm{ab}}}{\sqrt{(C_p+C_{\mathrm{ab}}+C_{\mathrm{bf}})C_{\mathrm{bf}}}}]\end{array}\right\}}$

Wherein: $\mathrm{\&alpha;}=\frac{C_a}{C_{\mathrm{br}}};C_{\mathrm{ab}}=\frac{C_a}{1+\mathrm{\&alpha;}};W_s=\frac{1}{\sqrt{M_a{C}_a}};Q_t=\frac{W_s{M}_a}{R_a};W_p=\frac{1}{\sqrt{M_p{C}_p}};$

$\frac{W_{\mathrm{bs}}}{W_s}=\frac{Q_{\mathrm{bt}}}{Q_t}=\sqrt{1+\mathrm{\&alpha;}};W_0=\sqrt[4]{{W_{\mathrm{bs}}}^2{W_p}^2\frac{C_p+C_{\mathrm{ab}}+C_{\mathrm{bf}}}{C_{\mathrm{bf}}}};s=\frac{\mathrm{jw}}{W_0}$

As can be seen, the characteristic of the system function of the system function characteristic that this use is novel and traditional fourth-order band-pass system is closely similar, is typical fourth-order band-pass function, and fourth-order band-pass responding system function has following general form:

$G\left(s\right)=\frac{\frac{A_1}{b_1{Q}^2}{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="Y20052005398900121.png,Y20052005398900122.png"\; state="\{\{state\}\}">s</figure-callout>}}^2}{1+\frac{a_1}{b_{1}Q}s+(2+\frac{1}{b_1{Q}^2}){\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="Y20052005398900121.png,Y20052005398900122.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+\frac{a_1}{b_1\mathrm{<figure-callout\; id="3"\; label="Q\; s"\; filenames="Y20052005398900121.png,Y20052005398900122.png"\; state="\{\{state\}\}">Q</figure-callout>}}{s}^{}{}^3+s^4}$

Wherein: A ₁Be system function gain, passband quality factor q=1/ Δ s; Δ s=s _H-s _L $\mathrm{\&Delta;s}=s_H-s_L;s_L=\sqrt{1+4Q^2}-1/2Q,s_H=1/s_L;$ s _LAnd s _HThe corresponding passband central frequency point amplitude decline 3dB of difference, pairing frequency; a ₁And b ₁For second order is low with the pairing coefficient value of function, (as Butterworth, Chebyshev) value is certain in several typical responses.Separating the coefficient equation can get:

Box body parameter: $C_{\mathrm{br}}=\frac{C_a}{{\left(\frac{b_{1}Q}{a_1{Q}_t}\right)}^2\left(\frac{A_1{b}_1{\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="Y20052005398900121.png,Y20052005398900122.png"\; state="\{\{state\}\}">Q</figure-callout>}}^2+A_1-b_1{Q}^2}{A_1{b}_1{Q}^2}\right)-1};C_{\mathrm{bf}}=A_1{C}_a{\left(\frac{a_1{Q}_t}{b_{1}Q}\right)}^2$

The passive radiator parameter: $W_p=W_s\frac{\sqrt{b_1(b_1{Q}^2-A_1)}}{a_1{Q}_t};C_p={\left(\frac{a_1{Q}_t}{b_{1}Q}\right)}^2\left(\frac{{A_1}^2}{b_1{Q}^2-A_1}\right)C_a$

Parameter for specific intended response passive radiator is certain, and just the compliance value of the resonance frequency of passive radiator and passive radiator can be by drawing Analysis of response.The resonance frequency of passive radiator is given by the following formula:

$f_p=\frac{1}{2\mathrm{\&pi;}\sqrt{M_{\mathrm{mp}}{C}_{\mathrm{mp}}}}=\frac{1}{2\mathrm{\&pi;}\sqrt{M_p{C}_p}};M_p=\frac{M_{\mathrm{<figure-callout\; id="2"\; label="mp\; S\; p"\; filenames="Y20052005398900121.png,Y20052005398900122.png"\; state="\{\{state\}\}">mp</figure-callout>}}}{{S_p}^{}};C_p=C_{\mathrm{<figure-callout\; id="2"\; label="mp\; S\; p"\; filenames="Y20052005398900121.png,Y20052005398900122.png"\; state="\{\{state\}\}">mp</figure-callout>}}{S_p}^{}{{}_{}}^2;$

LLM _MpBe the equivalent mass of passive radiator, unit is Kg, M _pEquivalent sound quality for passive radiator

LLC _MpBe the equivalent force of passive radiator, unit is m/N, C _pFor the equivalent sound of passive radiator suitable

As can be seen, the resonance frequency of adjusting passive radiator can realize by the weight of change vibration sounding device and the coefficient of elasticity of ring, this is very easy to realize in actual use, the adjustment of passive radiator resonance frequency simultaneously can be carried out under the situation that does not change its physical dimension fully, and this has it and installs and advantage easy to adjust.

Simultaneously as can be seen under the situation of conditions permit, the area of vibration sounding device can be done greatly (general all greater than the effective radiating area of active loud speaker) as much as possible, as long as guarantee that equivalent sound quality and equivalent sound are along constant, then can not change the resonance frequency of passive radiator, area increases a weight that needs adjustment vibration sounding device and the compliance of ring gets final product, can not cause not having the increase that influences the longitudinal size of installing, compared to six traditional rank bandpass systems, the utility model has advantageous advantage in the mini-system design.

And sound radiation pressure and swept area and vibration velocity have such relation:

$P=\frac{\mathrm{\&rho;f}}{2r}{V}_p{S}_p$ ------P is a sound radiation pressure, and Vp is the radiator vibration velocity, and Sp is the radiator effective radiating area

The increase of swept area means under the situation of the same sound pressure level of output, the speed of the passive radiator institute driven air that the utility model adopted will greatly reduce, and the effective radiating area of passive radiator is much larger than the area of traditional phase-reversing tube, this just means under the situation of the same sound pressure level of output, the vibration velocity of air that the utility model promotes is far below traditional six rank band general formula systems, therefore the utility model can effectively reduce the low frequency radiation distortion, and the system that shows significantly reduces doing low frequency playback time windage noise.

In sum, the utility model has following advantage:

1, with passive radiator swept area big feature, export on an equal basis under the acoustic pressure situation, reduced air vibration speed, and improved the low frequency radiation distortion, the system that shows significantly reduces doing low frequency playback time windage noise;

2, because the adjustment of the major parameter of passive radiator and physical dimension do not have inevitable relation, the enough size degrees of freedom of knot compare higher, therefore have bigger flexibility on structural design, are particularly suitable for the design of small-sized sound system;

3, because passive radiator separates resonance box and outside air, can effectively suppress of the influence of the interior sound wave normal-mode of resonance box to system's acoustic radiation, effectively reduce the nonlinear distortion of system;

4, have and the similar Frequency Response of traditional fourth-order band-pass formula speaker system.

Claims (6)

1, a kind of fourth-order band-pass with passive radiator, comprise resonance box, the active loud speaker, it is characterized in that: on resonance box, install and be provided with passive radiator, passive radiator is fixed on the resonance box, and, make passive radiator become the integral body of sealing with the resonance box-shaped with bearing's sealing.

2, the fourth-order band-pass with passive radiator as claimed in claim 1, it is characterized in that initiatively loud speaker is traditional direct radiator type electrodynamic loudspeaker, the particular location of its installation is that difference is the cavity radiative acoustic wave forwards, backwards on the middle dividing plate of resonance box front and back cavity.

3, the fourth-order band-pass with passive radiator as claimed in claim 2 is characterized in that initiatively loud speaker adds with the dividing plate junction to be lined with the sealing cotton.

4, the fourth-order band-pass with passive radiator as claimed in claim 1, it is characterized in that the initiatively described resonance box of loud speaker, be made up of former and later two resonance boxes, on the resonance box, two resonance boxes were by initiatively loud speaker connection before described passive radiator was installed on.

5, as claim 1 or 4 described fourth-order band-pass with passive radiator, it is characterized in that the initiatively described passive radiator of loud speaker, make by composite material, connect the vibration sounding device of a plane or the conical surface by the good ring of elasticity; Ring has good elasticity, and the vibration sounding utensil is prepared enough enough rigidity.

6, the fourth-order band-pass with passive radiator as claimed in claim 5, it is characterized in that the initiatively above-mentioned passive radiator of loud speaker, its concrete structure is: the centre is the vibration sounding device, this vibration sounding device is slab construction or pyramidal structure, the outer rim of vibration sounding device has ring, ring is to being externally connected with support, and the vibration sounding device is connected on the resonance box by support.

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