JPH11150782A - Speaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the increase of lowest resonance frequency by providing an airtight box with one aperture or a duct in a speaker box thereby suppressing the change of the stiffness of air in the speaker box. SOLUTION: At a rear surface board 19 a speaker unit 3 is opposed to in the speaker box 1, the airtight box 21 which is a rectangular parallelopiped of a small capacity, is provided with an opening 21a and constitutes the resonator of Helmoholtz is provided continuously to this board 19. In this case, the direction of the opening 21a of the box 21 is made equal to the driving direction of the oscillation board 10 of this unit 3 and the direction of the force of air injected from this aperture 21a is made equal to the direction of the driving direction of the board 10. Thus, the change of the volume in the box 1 due to the oscillation of the board 10 of the unit 3 is absorbed by the box 21 provided with one opening 21a to absorb pressure change in the speaker box 1, thereby prevent the stiffness of the air from increasing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker device suitable for being applied to a small and lightweight speaker device.

[0002]

2. Description of the Related Art Conventionally, a small and lightweight speaker device as shown in FIG. 8 has been proposed. In FIG. 8, reference numeral 1 denotes a small and lightweight speaker box made of synthetic resin or the like, and a speaker unit 3 is fixed to a speaker mounting hole 2a formed on the upper side of a baffle plate 2 fixed to the front of the speaker box 1.

The speaker unit 3 is configured, for example, as follows. As shown in FIG. 8, a ring-shaped magnet 4, a plate 5 and a yoke 6 mounted so as to sandwich the ring-shaped magnet 4 are provided, and a magnetic field is provided between the inner peripheral side of the plate 5 and the center pole 6a of the yoke 6. The void 7 is formed. Also, this plate 5
A frame 8 of a speaker is attached to the frame 8, and an edge 9 is provided on an outer peripheral portion of the frame 8, and the outer peripheral portion of the cone-shaped diaphragm 10 is held 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.
a so as to be inserted into the magnetic gap 7 formed by a. Reference numeral 17 denotes a damper for holding the voice coil 12 in the magnetic gap 7.

An audio signal from an input terminal 13 provided at a predetermined position outside the speaker box 1 is transmitted to a connection line 14.
To the terminal 15 of the speaker unit 3, and the audio signal from the terminal 15 is supplied to the voice coil 12 via the tinsel wire 16.

Further, a tubular body constituting a bass reflex duct 18 having an opening 18a on the same surface as the speaker mounting hole 2a of the baffle plate 2 is provided, and a sound emitted from the rear surface of the diaphragm 10 of the speaker unit 3 is provided. The phase is inverted so that it is radiated from the duct 18 to the outside of the speaker box 1 so as to expand the bass range of the sound coming out of the front surface of the diaphragm 10.

[0007]

In a small speaker device using such a small speaker box 1, the lowest resonance frequency of the speaker unit 3 rises due to the stiffness of air in the speaker box 1, There is an inconvenience that low-frequency sounds cannot be obtained.

That is, if the change in the stiffness of the air in the speaker box 1 does not affect the speaker unit 3, the original lowest resonance frequency is obtained without changing the original resonance frequency of the speaker unit 3.

However, when the diaphragm 10 of the speaker unit 3 vibrates, for example, when the diaphragm 10 moves inside the speaker box 1, the stiffness of the air in the speaker box 1 is reduced by the vibration of the speaker unit 3. The stiffness is determined by the caliber of the plate 10 and the volume of the speaker box 1. The stiffness of the air is added to the stiffness of the support system of the diaphragm 10 of the speaker unit 3, and the lowest resonance frequency of the speaker device is increased.

That is, the stiffness of the support system of the diaphragm 10 of the speaker unit 3 is So, and the stiffness of the air is S.
c, and when the mass of the vibration system of the speaker unit 3 is m ₀ , the lowest resonance frequency f ₀ is It is.

Conventionally, a duct 18 is provided as shown in FIG. 8 to provide a bass reflex structure in order to eliminate the rise of the lowest resonance frequency f ₀ of the speaker device as much as possible. However, a speaker having a bass reflex structure as shown in FIG. also in apparatus, due to the influence of stiffness Sc of air of the speaker box 1, the lowest resonance frequency f ₀ of the speaker apparatus is a disadvantage to rise.

In view of the above, the present invention proposes a speaker device which does not raise the lowest resonance frequency in the speaker box due to the stiffness of air.

[0013]

According to the speaker device of the present invention, an airtight box having one opening or a duct is provided in a speaker box to which a speaker unit for emitting sound is mounted, and air in the speaker box is removed. The stiffness does not change.

According to the present invention, since the airtight box having one opening or duct is provided in the speaker box, the change in the volume in the speaker box due to the vibration of the diaphragm of the speaker unit is reduced. The airtight box having a plurality of openings or ducts absorbs, the pressure change in the speaker box is absorbed, the stiffness of the air in the speaker box does not change, and the lowest resonance frequency f ₀ of the speaker device is air. , The stiffness Sc does not increase, and accordingly, the low-frequency reproduction band is expanded.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a speaker device according to the present invention will be described below with reference to FIG. In FIG. 1, parts corresponding to those in FIG. 8 are denoted by the same reference numerals.

FIG. 1 is a longitudinal sectional view of a speaker device according to this embodiment. In this embodiment, a baffle plate 2 is provided on the front of a small and lightweight speaker box 1 formed of a synthetic resin or the like. 2, a speaker mounting hole 2a is formed on the upper side of the baffle plate 2.
The speaker unit 3 is fixed inside.

The speaker unit 3 is configured, for example, as shown in FIG. That is, the ring-shaped magnet 4,
A magnetic circuit is formed by providing a plate 5 and a yoke 6 which are attached so as to sandwich the ring-shaped magnet 4, and an inner peripheral side of the plate 5 and a center pole 6 a of the yoke 6.
And a magnetic gap 7 is formed between them.

A funnel-shaped frame 8 made of steel or the like for the speaker is attached to the plate 5.
An edge 9 is provided on the outer peripheral portion of the diaphragm, and the outer peripheral portion of the cone-shaped diaphragm 10 is held 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 mounted on the center pole 6 of the plate 5 and the yoke 6.
a so as to be inserted into the magnetic gap 7 formed by a. The voice coil 12 is held in the magnetic gap 7 by a damper 17.

In addition, a voice signal is transmitted from an input terminal 13 provided at a predetermined position outside the speaker box 1, in the illustrated example, on the outer surface of the rear panel 19 of the speaker box 1.
The audio signal is supplied to the terminal 15 of the speaker unit 3 via the terminal 4 and the voice signal from the terminal 15 is supplied to the voice coil 12 via the tinsel wire 16.

Further, a tubular body 20 constituting a bass reflex duct 18 having an opening 18a on the same surface as the speaker mounting hole 2a of the baffle plate 2 is provided.
The phase of the sound emitted from the rear surface of the diaphragm 10 is inverted and radiated from the duct 18 to the outside of the speaker box 1 so as to expand the bass range of the sound emitted from the front surface of the diaphragm 10.

In the present embodiment, a rectangular opening 21a having a relatively small volume is formed in a rear plate 19 of the speaker box 1 facing the speaker unit 3 and connected to the rear plate 19.
An airtight box 21 constituting a Helmholtz resonator having the following is provided.

In this case, the opening 2 of the hermetic box 21
The direction of 1a is set to the same direction as the driving direction of the diaphragm 10 of the speaker unit 3, and the force of the air radiated from the opening 21a is set to the same direction as the driving direction of the diaphragm 10.

As described above, according to this embodiment, since the airtight box 21 having one opening 21a is provided in the speaker box 1, the diaphragm 10 of the speaker unit 3 is provided.
The change in volume in the speaker box 1 due to the vibration of the air is absorbed by the hermetic box 21 having the one opening 21a, and the change in pressure in the speaker box 1 is absorbed. Since the stiffness Sc does not increase, there is an advantage that the low-frequency reproduction band is expanded accordingly.

For example, when the diaphragm 10 of the speaker unit 3 moves forward and there is no airtight box 21 constituting the Helmholtz resonator, the pressure of the air inside the speaker box 1 becomes weak. A large air pressure is applied to the diaphragm 10 of the unit 3 from the outside, and the lowest resonance frequency f ₀ of the speaker unit 3 rises.
When there is an airtight box 21 that constitutes a Helmholtz resonator having the following equation, air instantaneously flows out of the airtight box 21 and the pressure of the air inside the speaker box 1 returns to the original equilibrium state.

That is, since the pressure of the air inside the speaker box 1 is always in an equilibrium state even when the diaphragm 10 of the speaker unit 3 vibrates, the volume inside the speaker box 1 and the diameter of the diaphragm 10 The stiffness Sc of the air determined by
₀ does not rise as it is.

When the volume in the speaker box 1 is actually divided into two equal to the volume of the hermetic box 21,
The balance between the pressures of these two volumes is increased, which is equivalent to doubling the volume of the speaker box 21, so that the effect is very large in a small speaker device.

In this embodiment, the airtight box 21
Direction of the opening 21a of the diaphragm 10 of the speaker unit 3
And the force of the air radiated from the opening 21a is the same as the driving direction of the diaphragm 10, so that the driving force of the diaphragm 10 of the speaker unit 3 is
The radiation power of the opening 21a is added, and if the speaker box 1 is fixed, the radiation power of the sound becomes stronger than usual and the sound quality is improved.

FIG. 7 shows an equivalent circuit of the example shown in FIG. 7, A is an audio signal source, m ₀ is the effective mass of the vibration system of the speaker unit 3, R ₀ is the resistance of the speaker unit 3, So is the stiffness of the support system of the speaker unit 3, and Sc is the speaker box 1. Air stiffness,
m _B is the mass of the airtight box 21, R _B is airtight box 2
1, S _B is the stiffness of the air in the airtight box 21, m _D is the mass of the opening 21a, m _D1 is the radiation mass of the opening 21a, and R _D is the radiation resistance of the opening 21a.

FIG. 2 is a cross-sectional view showing another example of the embodiment of the present invention. 2 will be described. In FIG. 2, parts corresponding to those in FIG.
The detailed description is omitted.

In the example shown in FIG. 2, a baffle plate 2 is provided on the front surface of a small and lightweight speaker box 1 made of synthetic resin or the like, and a speaker mounting hole 2a is formed at a predetermined position of the baffle plate 2. The speaker unit 3 is fixed inside the second speaker mounting hole 2a.

In the example shown in FIG. 2, the rear panel 19 of the speaker box 1 facing the speaker unit 3
A semi-cylindrical hermetic box 2 constituting a Helmholtz resonator having a cylindrical duct 22 continuously to the rear face plate 19
3 is provided.

In this case, the duct 22 of the hermetic box 23 is provided at a position facing the speaker unit 3, and the direction of the duct 22 of the hermetic box 23 is set as the driving direction of the diaphragm 10 of the speaker unit 3. An opening 22 a of the diaphragm 22 is provided so as to face the rear surface of the speaker unit 3 so that the force of the air radiated from the duct 22 is in the same direction as the driving direction of the diaphragm 10.

One and the other side plates 24a and 24b of the speaker box 1 and a semi-cylindrical airtight box 23
And openings 25a and 26 in the rear plate 19, respectively.
a to form ducts 25 and 26 having a.

The ducts 25 and 26 each constitute a bass reflex, inverting the phase of the sound emitted from the rear surface of the diaphragm 10 of the speaker unit 3, and radiating the sound from the ducts 25 and 26 to the outside of the speaker box 1 respectively. The bass range of the sound emitted from the front surface of the diaphragm 10 is expanded. Other configurations are the same as in the example of FIG.

It can be easily understood that the same effect as that of the example of FIG. 1 can be obtained in the example of FIG. The equivalent circuit of FIG. 2 is the same as that of FIG.

FIG. 3 is a cross sectional view showing another example of the embodiment of the present invention. 3 will be described. In FIG. 3, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the example shown in FIG. 3, a baffle plate 2 is provided on the front surface of a small and lightweight speaker box 1 made of synthetic resin or the like, and a speaker mounting hole 2a is formed at a predetermined position of the baffle plate 2. The speaker unit 3 is fixed inside the second speaker mounting hole 2a.

In the example shown in FIG. 3, a cylindrical duct 30 is provided behind the speaker unit 3 in the speaker box 1.
A hermetic box 31 having a square cylindrical shape and constituting a Helmholtz resonator having

In this case, the duct 30 of the hermetic box 31 is provided on the surface opposite to the speaker unit 3 and the direction of the duct 30 of the hermetic box 31 is set as the driving direction of the diaphragm 10 of the speaker unit 3. The opening 30a of the duct 30 is provided on the surface of the airtight box 31 opposite to the speaker unit 3 so that the force of the air radiated from the duct 30 is opposite to the driving direction of the diaphragm 10. .

In the example of FIG. 3, the speaker box 1 is of a closed type, and the other components are configured in the same manner as in FIG.

According to the example of FIG. 3, the airtight box 31 having one duct 30 is provided in the speaker box 1 as in the example of FIG.
The change in volume in the speaker box 1 due to the vibration of zero is absorbed by the hermetic box 31 having the one duct 30, the change in pressure in the speaker box 1 is absorbed, and the air in the speaker box 1 is absorbed. Since the stiffness Sc does not increase, there is an advantage that the low-frequency reproduction band is expanded accordingly.

In the example shown in FIG. 3, the direction of the duct 30 of the airtight box 31 is set to the same direction as the driving direction of the diaphragm 10 of the speaker unit 3, and the opening 30 of the duct 30 is opened.
Since the force of the air radiated from a is made opposite to the driving direction of the diaphragm 10, the direction of the driving force of the diaphragm 10 of the speaker unit 3 and the direction of the radiation force of the duct 30 are different. On the contrary, the small and lightweight speaker boxes 1 support each other and are hard to move, and the power of low-frequency radiation is very strong, which has the advantage of improving the sound quality.

FIG. 4 is a cross sectional view showing another example of the embodiment of the present invention. To explain this example of FIG.
In FIG. 4, the portions corresponding to FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the example of FIG. 4, a baffle plate 2 is provided on the front surface of a small and lightweight cylindrical speaker box 1 formed of synthetic resin or the like, and a speaker mounting hole 2a is formed at a predetermined position of the baffle plate 2. The speaker unit 3 is fixed inside the speaker mounting hole 2a of the baffle plate 2.

In the example of FIG. 4, the speaker unit 3 constituting the Helmholtz resonator having the cylindrical duct 40 is substantially flat at the rear of the speaker unit 3 in the cylindrical speaker box 1. A cylindrical airtight box 41 is provided.

In this case, the duct 40 of the hermetic box 41 is provided on the side opposite to the speaker unit 3, the direction of the duct 40 of the hermetic box 41 is set as the driving direction of the diaphragm 10 of the speaker unit 3,
The opening 40a of 0 is provided on the opposite side of the airtight box 41 from the speaker unit 3 so that the force of the air radiated from the duct 40 is opposite to the driving direction of the diaphragm 10.

In the example of FIG. 4, the speaker box 1 is of a closed type as in the example of FIG. 3, and the rest is configured in the same manner as in FIG. It can be easily understood that the same operation and effect as in the example of FIG. 3 can be obtained in the example of FIG.

FIG. 5 is a cross sectional view showing still another example of the embodiment of the present invention. 5 will be described. In FIG. 5, parts corresponding to those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 5 shows the speaker box 1 of FIG.
Openings 3 on the rear panel 19 on both sides of the airtight box 31 inside
This is provided with cylindrical ducts 32 and 33 having 2a and 33a.

The ducts 32 and 33 constitute a bass reflex, respectively, invert the phase of the sound emitted from the rear surface of the diaphragm 10 of the speaker unit 3 and radiate the sound from the ducts 32 and 33 to the outside of the speaker box 1, respectively. The bass range of the sound emitted from the front surface of the diaphragm 10 is expanded.

The example of FIG. 5 is otherwise the same as the example of FIG. It can be easily understood that the example of FIG. 5 has the same operation and effect as the example of FIG.

FIG. 6 is a cross sectional view showing another example of the embodiment of the present invention. 6 will be described. In FIG. 6, parts corresponding to those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The example shown in FIG. 6 is located at a predetermined symmetrical position with respect to a line connecting the center line between the speaker unit 3 and the duct 40 on the rear side of the cylindrical speaker box 1 shown in FIG. A cylindrical duct 42 and 43 having openings 42a and 43a on the side are provided.

The ducts 42 and 43 constitute a bass reflex, respectively, inverting the phase of the sound emitted from the back of the diaphragm 10 of the speaker unit 3 and radiating the sound from the ducts 42 and 43 to the outside of the speaker box, respectively. The bass range of the sound emitted from the front of the plate 10 is expanded.

In this embodiment, the ducts 42 and 43 are connected to the speaker unit 3 behind the speaker box 1 and the duct 4.
This duct 4 is provided symmetrically with respect to the line connecting the center line with zero.
The radiation powers of 2 and 43 are balanced, and the speaker box 1 does not move.

The configuration of FIG. 6 is otherwise the same as that of FIG. It can be easily understood that the example of FIG. 6 has the same operation and effect as the example of FIG. 3 like the example of FIG.

The speaker unit 3 is not limited to the above example, and various speaker units such as a magnetic shield type speaker unit and a magnetic shield type speaker unit provided with a shield cover can be used.

Further, the present invention is not limited to the above-described example, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0060]

According to the present invention, since the airtight box having one opening or duct is provided in the speaker box, the change in the volume in the speaker box due to the vibration of the diaphragm of the speaker unit can be reduced by this one. The airtight box having an opening or duct absorbs the change in pressure in the speaker box, the stiffness of air in the speaker box does not change, and the lowest resonance frequency f ₀ of the speaker device is Since the stiffness Sc does not increase, there is an advantage that the low-frequency reproduction band is expanded accordingly.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of an embodiment of a speaker device of the present invention.

FIG. 2 is a cross-sectional view showing another example of the embodiment of the present invention.

FIG. 3 is a cross-sectional view showing another example of the embodiment of the present invention.

FIG. 4 is a cross-sectional view showing another example of the embodiment of the present invention.

FIG. 5 is a cross-sectional view showing another example of the embodiment of the present invention.

FIG. 6 is a cross sectional view showing another example of the embodiment of the present invention.

FIG. 7 is a diagram showing an equivalent circuit of FIG. 1;

FIG. 8 is a longitudinal sectional view showing an example of a conventional speaker device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Speaker box, 2 ... Baffle board, 3 ... Speaker unit, 21, 23, 31, 41 ... Airtight box, 2
1a, 22a, 30a, 40a ... opening, 22, 30, 4
0 ... duct

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiro Akihiro 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo In-house Sony Corporation (72) Inventor Naoki Watanabe 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo In-house Sony Corporation (72) Inventor Kenji Tokushige 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo In-house Sony Corporation

Claims (3)

[Claims] An airtight box having one opening or a duct is provided in a speaker box to which a speaker unit for sound emission is attached, so that the stiffness of air in the speaker box does not change. A speaker device characterized by the above-mentioned. 2. The speaker device according to claim 1, wherein the direction of the opening or the duct of the airtight box is the same as the driving direction of the diaphragm of the speaker unit, and the force of air radiated from the opening or the duct. Is the same as the driving direction of the diaphragm. 3. The speaker device according to claim 1, wherein the direction of the opening or the duct of the airtight box is the same as the driving direction of the diaphragm of the speaker unit, and the force of air radiated from the opening or the duct. A direction opposite to the driving direction of the diaphragm.