JPH11308689A - Loudspeaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance low frequency sound components by providing a compliance to a duct in a loudspeaker box with respect to one speaker, so as to configure a simple vibrator thereby suppressing rocking of a light speaker box due to a reaction of a sound radiation force of the speaker. SOLUTION: A duct 18 provided to a baffle board 2 of a loudspeaker box 1, in which a speaker 3 is placed or to a rear face board 1B is formed to be freely rocked and a compliance component is provided to the duct 18 or a movable vibrator 25 is provided to the duct 18, an output change in air in the speaker box 1 by driving a diaphragm 10 is used for a drive source and an acting force to cancel a reaction force with respect to a sound radiation force of the diaphragm 10 of the speaker 3 is produced to a movable vibrator 25 or the duct 18 formed to be freely rocked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small and lightweight loudspeaker device, and more particularly to a device for canceling or attenuating a reaction force of a sound radiation force of a loudspeaker diaphragm via a vibrating body disposed in a loudspeaker box. The present invention relates to a loudspeaker device.

[0002]

2. Description of the Related Art Conventionally, as an effective means for extending the low-frequency reproduction limit of a speaker device, for example, an opening and a duct are provided in a baffle plate provided with a speaker, and a phase of a sound emitted from a back surface of a diaphragm of the speaker is adjusted. A bass reflex type (phase inversion type) speaker device which inverts and radiates to the outside through an opening through a duct to enhance the sound wave emitted from the diaphragm of the speaker to the front so as not to distort the bass range is well known. Have been.

In such a phase inversion type speaker device, a speaker 3 is fixed opposite a speaker sound emission hole 2a formed in a baffle plate 2 provided on a front surface of a speaker box 1 as shown in FIG.

For example, as shown in FIG. 6, the speaker 3 is provided with a ring-shaped magnet 4, a plate 5 and a yoke 6 mounted so as to sandwich the ring-shaped magnet 4, and an inner peripheral side of the plate 5 and a yoke. The magnetic gap 7 is formed between the center gap 6 and the center pole 6a. Plate 5
The frame 8 of the speaker 3 is attached to the
An edge 9 is provided on the outer peripheral portion of the diaphragm 8, and the outer peripheral portion of the cone-shaped diaphragm 10 is held on the frame 8 by the edge 9.

On the other hand, a voice coil bobbin 11 is mounted on the inner peripheral portion of the diaphragm 10, and a voice coil 12 is wound around the voice coil bobbin 11, and the voice coil 12 is fixed by a center pole 6a of the plate 5 and the yoke 6. It is designed to be inserted into the formed magnetic gap 7. Reference numeral 17 denotes a damper for holding the voice coil 12 in the magnetic gap 7.

An acoustic signal from an input terminal 13a provided at a predetermined position outside the speaker box 1 is connected to a connection line 1
4a to the terminal 15 of the speaker 3 via the terminal 15a.
Of the voice coil 12 via the tinsel wire 16
To supply.

[0007] Further, the speaker sound emission hole 2a of the baffle plate 2
A duct 18 having an opening 18a is provided on the same surface as the above, and the phase of the sound emitted from the back surface of the diaphragm 10 of the speaker 3 is inverted and radiated from the duct 18 to the outside of the speaker box 1. The bass range of the sound coming out from the front is expanded.

As described above, by using a phase inversion type speaker device, the bass reproduction limit can be lowered as compared with the sealed type, and about 80% of the bass resonance frequency f ₀ of the speaker 3 can be obtained.
It is said that the low-frequency reproduction range can be extended to a degree.

In such a speaker device, as shown in FIG. 6, sound radiation force F ₁ due to vibration of diaphragm 10 of speaker 3 is obtained.
Is the diaphragm 10 of the speaker 3 on the equivalent mass M ₁ of the speaker 3.
Acceleration α ₁ that is working in, expressed by _{F 1 = M 1 · α 1} . To such sound radiation force F _1, the reaction force -F ₁ toward the speaker box 1 from the rear side of the diaphragm 10 also becomes remarkable the smaller the volume of the speaker box 1 speaker device is small and light, The air in the speaker box 1 is repeatedly compressed and expanded by the vibration of the diaphragm 10, and this air acts as a force to return the diaphragm 10 to its original position. There was a problem that was hindered.

In order to solve such a problem, the applicant has previously proposed a speaker device as shown in FIG. 7. In FIG. 7, portions corresponding to those in FIG. 6 are denoted by the same reference numerals.

In FIG. 7, a speaker box 1 is formed of a synthetic resin into a box shape integrally with a baffle plate 2. The speaker 3 having the same configuration as that described in detail with reference to FIG. 6 is fixed to the speaker sound emission hole 2a formed on the upper side of the baffle plate 2. The first duct 18 and the opening 18a disposed below the baffle plate 2 are integrally formed when the baffle plate 2 is molded.

A speaker sound emission hole 2b is formed at a position opposite to the speaker sound emission hole 2a formed on the baffle plate 2 above the rear face plate 1B, so that the second speaker 3b, preferably the speaker 3 and the back surface, are connected to each other. Is fixed to the rear plate 1B so that the first
Second duct 18b having a larger duct diameter than the second duct 18
Are overlapped within a predetermined length of the first duct 18 and are planted integrally with the rear plate 1B so as to form a concentric cross section, and the first through the opening 18c of the second duct 18b.
Equivalent mass M of air radiating to the opening 18a of the duct 18
_D and the equivalent resistance _RD are configured to be large.

Further, the first and second speakers 3 and 3b
Are supplied with the same input acoustic signal via input terminals 13a and 13b and connection lines 14a and 14b disposed on the rear panel 1B.

According to the speaker device shown in FIG.
Radiation force F _D1 between the first and second ducts 18 and 18b
And _{F D2 / 2 + F D2 /} 2 of the reaction force -F _D1 and -F _D2 /
2 + (− F _D2 / 2) are canceled out, so that the first and second
Loudspeakers 3 and 3b reactive force -F ₁ and -F ₂ of radiation force F ₁ and F ₂ of F ₁ ≒ F ₂ Tosureba can each other to cancel.

[0015]

However, the above-described structure requires a pair of speakers 3 and 3b having substantially the same structure in the speaker box 1, making it difficult to reduce the size of the speaker box 1 and increasing the cost. There was a problem.

Further, the vibration system of the speaker was made equal.
In one loudspeaker, the higher the low-band resonance frequency f ₀ , the higher the resonance sharpness Q becomes in proportion to f ₀ , so that there is a problem that it is not suitable for low-frequency reproduction.

An object of the present invention is to provide a speaker device which has solved the above-mentioned problems.
A simple movable vibrator is arranged in the duct to counteract the reaction force of the sound radiation force of the speaker, thereby expanding the low frequency range and providing powerful low frequency radiation, while preventing the swing of the lightweight speaker box. It is intended to obtain a possible speaker device.

[0018]

SUMMARY OF THE INVENTION A speaker device according to the present invention is a speaker device having a speaker disposed in a speaker box and having a phase inversion type duct. It was done.

According to the loudspeaker apparatus of the present invention, it is possible to obtain a loudspeaker capable of canceling out or attenuating the reaction force of the sound radiation force of the loudspeaker only by adding compliance to the duct for phase inversion.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a small speaker device according to the present invention will be described below with reference to FIGS. FIG.
Parts corresponding to those of the speaker device shown in FIG. 7 are denoted by the same reference numerals.

FIG. 1 is a side sectional view showing one embodiment of the speaker device of the present embodiment, in which a speaker 3 described in detail in FIG. 6 is disposed in a speaker box 1 having the same configuration as that described in FIG. The baffle plate 2 of the speaker box 1 has the same structure except for the following description.

In the speaker device shown in FIG. 1, the speaker box 1 is formed of an ABS resin or the like into a substantially rectangular parallelepiped shape, and faces the speaker sound emission hole 2a formed in the baffle plate 2 as shown in FIG. The speaker 3 is fixed.

An opening 18a of a duct 18 is formed substantially at the center on the left and right sides of the baffle plate 2 on the lower side of the speaker 3. As shown in the perspective views of FIGS. 1 and 5A, the duct 18 is made of synthetic resin and integrated with the baffle plate 2 and has a corrugated concavity and valley having the same shape as a speaker damper or the like. The duct 18 is cantilevered via the movable portion 20 provided with the slab.

By arranging the flexible duct 18 in the speaker box 1 as described above, compliance can be given by the movable portion 20, but the stiffness is sufficiently large as compared with the speaker damper or the like. Serve as weights, are given an equivalent mass, and function as the vibrating body 25.

When the speaker 3 is driven in the above configuration, the sound radiation force F ₁ of the diaphragm 10 can be expressed as F ₁ = M ₁ · α ₁ .
Here, M ₁ is the equivalent mass of the vibration system of the speaker 3, and α ₁ is the acceleration of the diaphragm 10.

[0026] The reaction force -F to the sound radiation force F ₁ of the above-mentioned
₁ also operates as −F ₁ = M ₁ · α ₁ .

Now, assume that the volume of air in the speaker box 1 is V _B , the static pressure is P, and the diaphragm 10 of the speaker 3
The effective area of S, the amplitude of the vibration plate 10 as the X, when driving the diaphragm 10 of the speaker 3 sound radiation forces in the direction indicated by F _1, the volume of air in the speaker box 1 V _B = S
-It changes so that it may expand by X minutes.

Accordingly, if the equivalent mass of the vibrating body 25 composed of the movable part 20 and the duct 18 as the weight is M ₃ and the acceleration of the vibrating body 25 is α ₃ , the above-mentioned V _B = S · X
The acting force of F ₃ = M ₃ · α _{3 using} the variation of the driving force as the driving source is the pressure in the speaker box 1 and the outside air (the speaker box 1).
The pressure acts on the vibrating body 25 based on the difference between the pressure and the pressure.

That is, when the effective area of the duct 18 of the vibrating body 25 is S _D , the acting force F ₃ acting on the vibrating body 25 is The sound radiation force F ₁ of the speaker 3 and the vibrating body 25
If you ask the acting force F ₃ of satisfying the following equation (1), the acting force of the movable plate 20 and the reaction force -F ₁ of the speaker 3 for variation in the volume V _B of the speaker box 1 of the vibrator 25 F _Three
Can causes mutually offset or damping the reaction force -F ₃ against.

F ₁ + F _D1 ≒ F ₃ (1) where F ₁ = M ₁ · α ₁ , F _D1 = M _D1 · α _{D 1} , F ₃ =
M ₃ · α ₃ , so M ₁ · α ₁ + M _D1 · α _D1 ≒ M ₃ ·
α ₃ . Here, _MD1 is the equivalent mass of the duct 18 when the air is radiated, and _αD1 is the acceleration of the radiated air from the opening 18a of the duct 18. Therefore, α _D1 = S / S _D · α ₁ , α ₃ ≒
α _D1 Can be obtained as Therefore, the equivalent mass M ₃ of the vibrating body 25 is Is required.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 2 shows an arrangement in which a vibrating body 25 having an equivalent mass of the duct 18 is provided on the rear face plate 1B of the speaker box 1.

In this embodiment, the speaker 3 has the same structure as that of FIG. 6, and the speaker box 1 has a duct opening 18a formed through a movable portion 20 similar to the perspective view of FIG. The rear end of the rear plate 1B is provided with a cantilevered duct 18. The duct 18 is preferably provided on the back of the speaker 3, that is, the center pole 6 constituting a magnetic circuit.
They are arranged to face each other so that the center of a and the center of the duct 18 coincide.

Also in the above case, the diaphragm 10 of the speaker 3 is F
When driven in the direction indicated by _1, based on the pressure difference of the speaker box 1 and out, the vibrating body 25 is moved in the direction indicated by the arrow F _3. Accordingly, the reaction forces -F _{1 and} -F ₃ and -F _{3 of the} vibrating body 25 including the speaker 3 and the duct 18 respectively.
The balance condition for canceling or attenuating F _D1 is F ₁ ≒ F ₃ +
It is obtained as F _D1 .

That is, M ₁ · α ₁ = M ₃ · α ₃ + M _D1 · α
It becomes _D1 . α ₃ = α ₁ , α _D1 = S / S _D · α ₁
M ₁ · α ₁ = M ₃ · α ₁ + M _D1 · S / S _D · α ₁ to M
_{3 · α 1 = M 1 ·} α 1 -M D · S / S D · α 1 = M 1 -
M _D1 · S / S _D as can be obtained equivalent mass M ₃ of the vibrator 25.

FIG. 3 shows still another embodiment of the present invention. In the case of FIG. 3, the configurations of the speaker 3 and the speaker box 1 are the same as those in FIG.

In FIG. 3, a vibrating body 25 is added to the duct 18 at a position opposite to the opening 18a. Of course, the vibrating body 25 may be fitted at any position in the longitudinal direction of the duct 18.

As shown in the perspective views of FIGS. 3 and 5B, the vibrating body 25 has an inner peripheral ring 2 integrally formed of a synthetic resin or the like.
2 and a movable portion 20 such as a flexible radial or damper or edge protruding from a position where the outer peripheral angle of the inner peripheral ring 22 is equally divided into three.
And an outer ring 23 connected to the movable portion 20 on the inner periphery.
A ring-shaped weight may be fitted and joined to the outer periphery of the outer peripheral ring 23 as necessary.

The inner diameter of the inner peripheral ring 22 of the vibrating body 25 is selected to be substantially the same as the outer diameter of the duct 18, and is fitted to and joined to the outer diameter of the duct 18.

The loudspeaker device having the above-described configuration also includes the loudspeaker 3.
To F ₁ direction of the sound radiation force of the diaphragm 10 of the vibrating body 25
In can be generated in the direction of applied force indicated by F ₃ which mutually cancel a reaction force -F ₃ of the reaction force -F ₁ and vibrator 25 of the speaker 3.

The acting force F ₃ at the vibrating body 25 is equal to that of the duct 1
8 of the reaction force -F radiation force F _D1 of the air from the opening 18a
The acting force of F ₃ + F _D1 to which _D1 is added is applied, so that F ₃ ≒ F ₁ + F _D1 is satisfied as described with reference to FIG. 1, and the equivalent mass of the vibrating body 25 is M ₃ = S _D / S
-M ₁ + M _D1 may be selected.

FIG. 4 shows still another embodiment of the speaker device of the present invention. Since the configurations of the speaker 3 and the speaker box 1 are exactly the same as those in FIG. 1, the corresponding parts are denoted by the same reference numerals. Therefore, a duplicate description will be omitted.

In the configuration shown in FIG.
This is the case where is arranged. The structure of the movable diaphragm 25 pivotally mounted in the duct 18 will be described with reference to FIGS. 4 and 5C.

The vibrating body 25 of this embodiment has an outer ring 23 having an outer diameter substantially equal to the inner diameter of the duct 18 and an outer circumference of the center disk 26 of 3 mm.
It has a flexible and radial movable part 20 protruding radially from an equally divided angular position, the tip of this movable part 20 is connected to the inner periphery of the outer peripheral ring 23, and a through hole is formed at the center of the center disk 26. 2
7 are integrally formed as a ring-shaped member 28 with a synthetic resin or the like.

The outer peripheral ring 23 of the above-mentioned ring-shaped member 28
Are fitted to both open ends of the duct 18 and are bonded via an adhesive or the like, and a weight 21 such as a metal round bar having substantially the same length as the duct is inserted into the through hole 27 of the center disk 26. And
By bonding with an adhesive or the like, the weight 21 forms a vibrating body 25 that can swing in the front and rear directions (the baffle plate 2 and the rear plate 1B) of the speaker box 1 via the movable portion 20.

Even in the speaker device having the above configuration, FIG.
Similarly to the above, by the balance formula of F ₁ + F _D1 ≒ F ₃ , the reaction force −F ₁ of the sound radiation force F ₁ of the speaker 3 and the reaction force −F ₃ of the force F ₃ of the vibrating body 25 can be canceled each other. It is. Equivalent mass M ₃ of the weight 21 of the vibrator 25 in this case is 1
In the same manner as in the above, it is easily obtained by selecting S _D / S (M ₁ + M _D1 ).

[0046]

According to the loudspeaker apparatus of the present invention, one loudspeaker is disposed in the loudspeaker box, and compliance is imparted to the baffle plate or the duct provided at a predetermined position on the rear panel of the loudspeaker box, or the movable vibration is provided. The reaction force against the sound radiation force of the diaphragm of the speaker can be canceled or attenuated only by providing the body. In particular, since the movable vibrator is driven by the pressure change of the air in the speaker box and the bass is enhanced through the phase inversion duct,
The reaction force of the speaker can be supported simply by holding the duct with a movable part such as a spring member.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a speaker device of the present invention.

FIG. 2 is another side sectional view of the speaker device of the present invention.

FIG. 3 is still another side sectional view (I) of the speaker device of the present invention.

FIG. 4 is still another side sectional view of the speaker device of the present invention (I
I).

FIG. 5 is a perspective view of a vibrating body used in the speaker device of the present invention.

FIG. 6 is a side sectional view of a conventional speaker device.

FIG. 7 is another side sectional view of a conventional speaker device.

[Explanation of symbols]

1 speaker box, 2 baffle board, 3 speaker, 18, 18b duct, 20 movable plate, 2
1 ‥‥ weight, 25 ‥‥ vibrator

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuo Azami 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Masayuki Hirooka 6-7-1 Kita Shinagawa, Shinagawa-ku, Tokyo No. 35 Sony Corporation

Claims (4)

[Claims] 1. A speaker device having a speaker disposed in a speaker box and having a phase inversion type duct, wherein the duct is provided with compliance. 2. The speaker device according to claim 1, wherein the duct is disposed on a rear plate of the speaker box facing a back surface of the speaker. 3. The speaker device according to claim 1, wherein the duct is held by the speaker box via a movable plate for providing compliance. 4. The duct according to claim 1, wherein a vibrating body having a movable plate for giving compliance and a weight for giving an equivalent mass is fitted to an outer or inner periphery of the duct. Speaker device.