JPH11308688A - Loudspeaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a loudspeaker system that has low frequency components expanded, a low frequency sound is emitted with high quality and rocking of a speaker box with a light weight is prevented by providing a movable vibrator to a baffle plate, while an internal pressure change in the speaker box is used for a driving force, so as to produce an operating force reversely in a sound radiation direction. SOLUTION: A movable vibrator 21 placed on a baffle plate 2 of a loudspeaker box 1 is moved simultaneously with air pressure fluctuations in the inside of the speaker box 1 through a volume VB of the speaker box 1. An active force F2 of the mobile vibrator 21 driven by a force of a pressure change is supported by a reaction force-F1 of a sound radiation force F1 of a speaker 3. Thus, rocking before and after the light weight speaker box 1 is suppressed simply, and the speaker system that powerfully reproduces a low sound frequency component is obtained. That is, a single speaker 3 is able to cancel or attenuate the reaction force-F1 of the sound radiation force by only arranging the movable vibrator 21 for the baffle plate 2 of the speaker box 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suitable speaker device in which a small and lightweight speaker is built in a speaker box. In particular, a pressure change in the speaker box when sound is emitted from the speaker is provided in the speaker box as a driving source. The present invention relates to a speaker device in which a vibrating body cancels or attenuates a reaction force of sound radiation from a speaker.

[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. 3, 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 loudspeaker device, the sound radiation force F ₁ due to the vibration of the diaphragm 10 of the loudspeaker 3 is equal to the acceleration α ₁ acting on the loudspeaker diaphragm 10 on the equivalent mass M ₁ of the loudspeaker 3, ie, F ₁ = M ₁ α Can be represented by 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 present applicant has previously proposed a speaker device as shown in FIG. 4. In FIG. 4, portions corresponding to those in FIG. 3 are denoted by the same reference numerals.

In FIG. 4, 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. 3 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 formed.

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. Are fixed to the rear panel 1B so as to face the speaker sound emission hole 2b, and the second duct 18b having a larger duct diameter than the first duct 18 overlaps within a predetermined length of the first duct 18. And planted integrally with the rear plate 1B so that a concentric cross section is formed,
And it is configured so as to increase the equivalent mass M _D and the equivalent resistance R _D of the air emitted through the opening 18c of the second duct 18b in the opening 18a of the first duct 18.

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 the two speakers, the higher the lowest resonance frequency f ₀ , the larger the resonance sharpness Q of the diaphragm 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. An object of the present invention is to use an inexpensive and relatively small-diameter diaphragm such as a fixed edge. It is an object of the present invention to obtain a speaker device that can expand a low frequency band and emit high-quality low frequency band by using one speaker, and can prevent swinging of a lightweight speaker box.

[0018]

A speaker device according to the present invention uses a speaker mounted on a baffle plate of a speaker box and a pressure change inside the speaker box caused by a reaction force in a direction opposite to a direction of sound emission from the speaker as a driving force. And a movable vibrator that is arranged on the baffle plate and generates an acting force in a direction opposite to the sound radiation direction.

According to the speaker device of the present invention, it is possible to obtain a device in which the reaction force of the sound radiation force can be canceled or attenuated by one speaker only by disposing the movable vibrator on the baffle plate of the speaker box. Can be

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a compact speaker device of the present invention will be described in detail with reference to FIGS. The parts corresponding to those of the speaker device shown in FIGS. 3 and 4 are denoted by the same reference numerals.

FIG. 1 is a side sectional view of the speaker device of this embodiment, in which a speaker 3 similar to that shown in FIG. 3 is disposed in a speaker box 1 having phase inversion type ducts 18 and 18b. Since the speaker box 1 has the same configuration as that of FIG. 4 except as described below, the description of the overlapping portions will be omitted.

In the speaker device shown in FIG. 1, a speaker box 1 is formed of an ABS resin or the like into a substantially rectangular parallelepiped shape, and a speaker sound hole 2a formed in a baffle plate 2 and a speaker sound hole 2a arranged opposite to the speaker sound hole 2a. A speaker 3 similar to that described in detail with reference to FIG.

Below the speaker 3, there are a duct 18 having a duct opening 18a having the same configuration as that described in detail in FIG. 4, and a duct 18b extending from the back plate 1B.

Further, in this embodiment, the speaker 3 of the baffle plate 2
An opening 19 is drilled on the upper side of the disk, and an outer peripheral portion of a disk-shaped movable plate 20 which is formed in a ring shape like an edge or a damper is inserted into the inner diameter of the opening 19, and is connected via an adhesive or the like. Are joined.

The weight 21a is located at the center of the movable plate 20.
Are joined to form a movable vibrating body 21. The mountain-shaped convex portion of the movable plate 20 is fixed so as to protrude toward the outside of the baffle plate 2. The movable plate 20 is made of cloth, synthetic resin, or the like.

[0026] In the above configuration, the sound radiation force F ₁ of the diaphragm 10 by driving the speaker 3 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.

[0027] 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.

Therefore, if the equivalent mass of the movable vibrating body 21 composed of the movable plate 20 and the weight 20a is M ₂ , and the acceleration of the movable vibrating body 21 is α ₂ , the above-mentioned V _B = S
The acting force of F ₂ = M ₂ α _{2 using} the variation of X as a drive source acts on the movable vibrator 21 based on the difference between the pressure in the speaker box 1 and the outside air (pressure outside the speaker box 1). Will be.

That is, when the effective area of the movable plate 20 of the movable vibrating body 21 is S ₁ , the driving source force F ₂ acting on the movable vibrating body 21 is If the sound radiation force F ₁ of the speaker 3 and the acting force F ₂ of the movable vibrator 21 satisfy the following expression (1), the reaction force −F ₁ of the speaker 3 and the mobility Vibrator 21
Can is to cancel or attenuate each other with the acting force F ₂ of the movable plate 20 of the speaker box 1 with respect to the change amount of volume V _B. F ₁ = M ₁ · α ₁ ≒ F ₂ = M ₂ · α _{2 Since} α ₂ = S / S ₁ · α ₁ , F ₁ = M ₁ · α ₁ ≒ F ₂ = M ₂ · S / S ₁ · α ₁ (1) Accordingly, the value of the equivalent mass M ₂ of the movable vibrating body 21 is M ₂ =
It is sufficient to select the S ₂ / S · M _1.

Note that the speaker box 1 shown in FIG.
Reaction force -F _D1 for sound radiation force F _D1 of 8 parts are balanced so as to cancel is performed together with the second duct 18b in the same manner as FIG. 4, lightweight speaker by the sound radiation force of the speaker 3 Since the swing of the box 1 in the front-rear direction (the direction of the baffle plate 2 and the rear plate 1B) is suppressed, the speaker device as a whole is disposed on the baffle plate 2 of the speaker box 1 by satisfying the expression (1). through the volume V _B of the vibrator 21 is the speaker box 1 mobility, pressure fluctuations in the air inside the speaker box 1 motion simultaneously acting force F ₂ of the mobility of the vibrator 21 driven by the force of this pressure change And the reaction force of the sound radiation force F ₁ of the speaker 3 −
Since F ₁ and has form as support each other strongly renewable speaker apparatus easily suppressed to low rocking back and forth lightweight speaker box 1 is obtained.

[0032] Incidentally, the diaphragm 10 and the diaphragm 10 of the effective area S ₁ of the diameter of the relationship between the diameter of each of the movable plate 20 of the movability of the vibration member 21 is a diaphragm 20 the speaker 3 of the above speaker 3 The movable plate 20 of the vibrating body 29 should be smaller than the effective area S as much as possible, for example, for a 65 mm aperture of the speaker 3.
By making the diameter of 1/10 about 6.5 mm, the sound pressure output loss of the speaker 3 can be reduced.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 2 shows a configuration in which an airtight container 22 is provided on the back side of the baffle plate 2 of the speaker box 1, and the above-described movable vibrator 21 is disposed in an opening of the airtight container 22.

In FIG. 2, portions corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted. In FIG.
The configuration of the first and second ducts 18 and 18b is shown in FIG.
For example, a cylindrical airtight container 22 is formed integrally with the baffle plate 2 on the upper side of the baffle plate 2 to which the speaker 3 is attached, and the opening of the cylindrical portion is described in detail in FIG. Weight 2 is provided at the center of movable plate 20 having the same configuration as
The movable vibrator 21 provided with Oa is provided.

The outer periphery of the movable plate 20 of the movable diaphragm 21 is joined to the inner periphery of the opening of the closed chamber container 22 via an adhesive. At this time the mountain-like protrusions of the movable plate 20 is attached as directed in box volume V _B side of the speaker box 1.

[0036] Therefore, with respect to the sound radiation forces in the direction indicated by F ₁ of the diaphragm 10 of the speaker 3 based on the pressure difference between the pressure and volume in the speaker box 1 in the closed room container 22, the mobility of the vibrating body 21 the movable plate 20 will be subjected to the action force of F ₂ directions.

Further, if necessary, a through hole 23 is formed at the center position of the baffle plate 2 constituting the closed chamber container 22, so that the load on the movable vibrating body 21 is reduced so as to facilitate movement. Good.

Also in the above-described configuration, the sound radiation force F of the speaker 3
The reaction force -F ₁ for ₁ by the action force F ₂ of the movability of the vibration member 21 (1) can be adjusted support as with expression.

Further, the closed chamber container 22 and the movable vibrator 2
By adjusting the resonance frequency constituted by 1 to the lowest resonance frequency f ₀ of the speaker 3, a more efficient speaker device can be obtained.

[0040]

According to the loudspeaker apparatus of the present invention, a single loudspeaker is disposed in a loudspeaker box, and a movable vibrator is provided at a predetermined position of a baffle plate, and the loudspeaker diaphragm reacts to the sound radiation force. The force can be canceled or damped. In particular, the movable vibrator is driven by the pressure change of the air in the speaker box, the bass is enhanced through the phase inversion duct, and the sound pressure output of the movable vibrator is reduced. By doing so, the configuration of the movable vibrating body is small and simple, so that a vibrator with no cost increase can be obtained.

[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 a side sectional view of a conventional speaker device.

FIG. 4 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
0a weight, 21mm movable vibrator, 22mm
Closed room container

Continuing from the front page (72) Inventor Tomohiro Ito 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Roshi Nakamura 6-35-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Inside the corporation

Claims (4)

[Claims] 1. A speaker attached to a baffle plate of a speaker box, and a pressure change inside the speaker box due to a reaction force in a direction opposite to a sound radiation direction from the speaker is provided on the baffle plate as a driving force, A speaker device, comprising: a movable vibrating body that generates an acting force in a direction opposite to the sound radiation direction. 2. The speaker device according to claim 1, wherein the movable vibrator is disposed so as to close a closed chamber having a volume of air provided on a back surface of the baffle plate. 3. The speaker device according to claim 2, wherein a through hole is formed in a baffle plate constituting the closed room. 4. The speaker device according to claim 1, wherein the outer periphery of the vibrating body is held via a movable plate such as an edge or a damper.