JPH1066193A - Speaker and speaker unit using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker which can realize an superior sound reproduction low tones, even in a speaker box of small capacity about a speaker which is used for various acoustic devices. SOLUTION: A front diaphragm 29 and a rear diaphragm 31 are connected to a voice coil 33, edges 28 and 30 are also connected to the diaphragms 29 and 31 respectively, and one end of each edge 28 and 30 is connected to a frame 27. The speaker consists of these two diaphragms 29 and 31. Even when it is connected to a speaker box of small capacity, the rise in the lowest resonance frequency (f0 ) is restrained and superior low tone reproduction can be realized by making the vibration area of the diaphragm 31 smaller than the one of the diaphragm 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker used for audio equipment and the like and a speaker device using the same.

[0002]

2. Description of the Related Art FIG.
This will be described with reference to FIG. FIG. 10 is a sectional view of a conventional speaker, and FIG. 11 is an equivalent circuit diagram of the speaker.

First, the structure of a speaker will be described with reference to FIG. Numeral 1 denotes a magnetic circuit in which a ring-shaped magnet 4 and a ring-shaped upper plate 5 are laminated and connected on a lower plate 3 provided with a center pole 2, and a frame 6 is connected to the magnetic circuit 1, 6
A cone-shaped diaphragm 8 is coupled to the peripheral portion of the diaphragm via an edge 7, and a voice coil 10 and a dust cap 11 that fit into the magnetic gap 9 of the magnetic circuit 1 are coupled to a central portion of the diaphragm 8. A damper 12 having a peripheral portion coupled to the frame 6 is coupled to an intermediate portion of the voice coil 10, and a terminal 13 provided on the frame 6 has one end of a flexible wire 14 such as a tinsel wire for providing input coupling to the voice coil 10. The other end is connected to the lead wire of the voice coil 10 at the middle part of the diaphragm 8.

When an input signal, which is an electric signal, is input to the terminal 13 in such a configuration, the input signal flows to the voice coil 10 via the flexible wire 14, and the voice coil 10 performs a piston movement in accordance with the input signal.
This operation is transmitted to the diaphragm 8 to obtain an acoustic output from the diaphragm 8.

FIG. 11 shows an equivalent circuit of the loudspeaker. Reference numeral 15 denotes a driving force, 16 denotes a motional impedance, 17 denotes a mechanical resistance of a vibration system, 18 denotes a vibration system mass, 19 denotes a vibration system compliance, Reference numeral 20 denotes a radiation resistance applied before and after the diaphragm, and reference numeral 21 denotes an additional mass applied before and after the diaphragm.

The minimum resonance frequency (f ₀ ) of the speaker is determined by the mechanical resistance 17 of the vibration system, the mass 18 of the vibration system, the compliance 19 of the vibration system, the mass 21 added to the front and back surfaces of the diaphragm, and the radiation resistance 20. However, when a speaker is actually used, some kind of acoustic load (such as a speaker box) is used.

[0007]

However, it is difficult to incorporate a conventional speaker into a small-capacity speaker box to realize sufficient bass reproduction. It is the compliance (capacitor) of the box in the equivalent circuit of Figure 11.
Are inserted in series, and the lowest resonance frequency (f ₀ )
Will rise.

Conventionally, in order to lower the minimum resonance frequency (f ₀ ), a method of increasing the compliance 19 of the vibration system or a method of increasing the mass 18 of the vibration system has been adopted, but a problem that sufficient characteristics cannot be obtained. Had.

The present invention eliminates such conventional disadvantages,
It is an object of the present invention to provide a speaker having a good bass reproduction capability and a speaker device using the same.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a speaker according to the present invention comprises at least two diaphragms whose peripheral parts are connected to a frame connected to a magnetic circuit, and the at least two diaphragms are provided. The area of the rear diaphragm is smaller than that of the front diaphragm, and a voice coil that fits into the magnetic gap of the magnetic circuit is coupled to the diaphragm.

With this configuration, the rise in the lowest resonance frequency (f ₀ ) when incorporated in the speaker box is minimized, and excellent bass reproduction can be realized.

[0012]

DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, a frame connected to a magnetic circuit is provided with at least two diaphragms whose peripheral portions are connected to each other. In this configuration, the area of the diaphragm on the rear side is made smaller than that of the diaphragm, and a voice coil that fits into the magnetic gap of the magnetic circuit is coupled to the diaphragm. With this configuration, the voice coil is incorporated in a speaker box. Then, it is possible to suppress the rise of the lowest resonance frequency (f ₀ ), and to achieve excellent low-frequency range reproduction.

According to a second aspect of the present invention, the space formed between at least two diaphragms is sealed, and the front and rear diaphragms operate in synchronization with each other to achieve excellent reproduction. Make it possible.

According to a third aspect of the present invention, at least two diaphragms are directly connected to the voice coil, respectively, and the two diaphragms operate with the voice coil and operate reliably in synchronization. Will be.

According to a fourth aspect of the present invention, of the at least two diaphragms, the rear diaphragm is coupled to the voice coil, and the front diaphragm is coupled to the rear diaphragm. Thus, reproduction in which the treble range is cut can be performed.

According to a fifth aspect of the present invention, a voice coil is combined with a diaphragm for a high-frequency range different from the at least two diaphragms. Become.

The invention according to claim 6 relates to a speaker device in which the above-described speaker is incorporated in a closed box, and excellent sound reproduction in a low sound range can be achieved.

According to a seventh aspect of the present invention, the above-mentioned speaker is incorporated in a bass reflex box, so that good bass reproduction can be realized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a speaker according to the first embodiment of the present invention, and FIG. 2 is an equivalent circuit diagram of the speaker.

In FIG. 1, reference numeral 22 denotes a magnetic circuit. The magnetic circuit 22 is formed by laminating a ring-shaped magnet 25 and a ring-shaped upper plate 26 on a lower plate 24 having a center pole 23 and bonding them by bonding or the like. It is configured.

On the upper surface of the magnetic circuit 22, a frame 27 is provided.
Are connected to each other, and an edge 28 is
The diaphragm 29 on the front side is attached via the
7 has a diaphragm 31 on the rear side through an edge 30
Is installed. The vibration area of the front diaphragm 29 and the rear diaphragm 31 is about 2: 1 and the rear diaphragm 31 is formed small.

At the center of the two diaphragms 29 and 31, a voice coil 33 in which a coil portion is fitted in the magnetic gap 32 of the magnetic circuit 22 is directly coupled. By coupling the voice coil 33 to the diaphragms 29, 31, the two diaphragms 29, 31 and the frame 2
The space 34 surrounded by the voice coil 7 and the voice coil 33 is sealed.

An inner peripheral portion of the damper 35 is connected to an intermediate portion of the voice coil 33, and an outer peripheral portion of the damper 35 is connected to the frame 27. Further, a dust cap 3 is provided at the center of the front surface of the vibration plate 29 on the front side.
6 are connected.

The frame 27 has a terminal 3
The terminal 37 is connected to one end of a flexible wire 38 made of a tinsel wire or the like. Is connected to the voice coil 3
3

With such a configuration, when an input signal is applied to the terminal 37, the input signal flows to the voice coil 33, and a driving force corresponding to the input signal is applied to the magnetic gap 32 of the magnetic circuit 22. The vibration is generated in the voice coil 33 that is stuck, and the diaphragms 29 and 31 coupled to the voice coil 33 are vibrated.
A sound is radiated from the 31 vibration surface.

FIG. 2 shows an equivalent circuit of a speaker having such a configuration. In FIG. 2, 39 is the driving force, 4
0 is the motional impedance, 41 is the mechanical resistance of the vibration system, 42 is the mass of the vibration system, 43 is the compliance of the vibration system, 44 is the mechanical resistance of the diaphragm edge on the back side, 45
Is the mass of the rear diaphragm, 46 is the compliance of the rear diaphragm edge, 47 is the radiation resistance of the front diaphragm, 48 is the added mass to the front diaphragm, 49 is the rear diaphragm The radiation resistance 50 is the added mass to the diaphragm on the back side.

This equivalent circuit is obtained by adding a mechanical resistance 44 and a mass 4 of the diaphragm 31 and the edge 30 on the rear side to the conventional speaker.
5. Compliance 46 is inserted in series. Further, since the radiation mass and the radiation resistance value added to the respective diaphragms 29 and 31 differ depending on the diaphragm area, the radiation masses (additional mass) 48 and 50 and the radiation resistance
The values of 7,49 are different. The radiation resistance indicates the density of air as ρ ₀ ,
Assuming that the effective radius of the diaphragm is a, the radiation mass M _MA is represented by M _MA = 8/3 · ρ ₀ a ³ .

The speaker of the present invention changes the area of the front and rear diaphragms 29 and 31 so that the lowest resonance frequency (f ₀ ) of the speaker box is lower than that of the conventional speaker when combined with a small-capacity speaker box. Can be lower. For example, when combined with a closed box, the acoustic capacity is inserted in series in the equivalent circuit of FIG. 2 due to the relationship between the box capacity and the vibration area, and the lowest resonance frequency (f ₀ ) is higher than that of a single speaker.

Assuming that the capacity of the closed box is V, the density of air is ρ ₀ , the effective vibration radius of the speaker is a, the sound velocity is c, and the pi is π, the acoustic capacity C _MB is C _MB = V / (Ρ ₀ c ² π ² a ⁴ ). That is, since the capacitance C _MB decreases in inverse proportion to the effective vibration radius, the lowest resonance frequency (f ₀ ) increases as the speaker has a larger vibration area.

However, small-diameter loudspeakers have problems such as efficiency and margin of amplitude, so that a very small-diameter speaker cannot be used.

In the loudspeaker of the present invention, the rise of the lowest resonance frequency (f ₀ ) is reduced by the diaphragm 31 having a small area on the rear side without reducing the vibration area of the diaphragm 29 on the front side, and a good bass range is improved. Reproduction can be realized.

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to FIG.

The speaker shown in FIG. 3 is basically the same as that shown in the first embodiment, and the same portions are denoted by the same reference numerals and only different points will be described.

That is, the inner peripheral end of the front-side diaphragm 29 is bent downward and connected to an intermediate portion of the rear-side diaphragm 31.
The voice coil 33 is connected to the center of the diaphragm 31 on the back side. Also, the diaphragm 29 on the front side
The point that the dust cap 36 is connected to the central portion of the second embodiment is the same as that of the first embodiment.

By adopting such a configuration, it is possible to realize reproduction in which a treble range as a speaker is cut off.

(Embodiment 3) Next, a third embodiment of the present invention will be described with reference to FIG. Since the third embodiment also has the same basic configuration as the first embodiment,
The same portions are denoted by the same reference numerals, and description thereof will be omitted.
Only the differences will be described.

That is, the feature is that a diaphragm 51 for a high frequency range, which also serves as a dust cap, is connected to the upper part of the voice coil 33.

According to this configuration, the loudspeaker has an improved reproduction capability in a high-frequency range, and a loudspeaker having a full-range reproduction band can be realized.

(Embodiment 4) Next, a speaker device according to a fourth embodiment of the present invention will be described with reference to FIGS. First, in FIG. 5, 52 is the speaker described in any of the first to third embodiments, and 53 is a closed box. As the speaker 52, one having the configuration of the first embodiment using a front diaphragm having a diameter of 16 cm and a rear diaphragm having a diameter of 12 cm was manufactured and assembled in a closed box 53. is there.

FIG. 6 is an equivalent circuit diagram of the speaker device, in which the compliance 54 of the closed box 53 is inserted in the equivalent circuit of the speaker shown in FIG. As can be seen from this equivalent circuit diagram, the closed box 53
Of the minimum resonance frequency (f ₀ ) can be reduced.

FIG. 7 shows a speaker device according to the fourth embodiment.
FIG. 6 is a sound pressure / frequency characteristic diagram of a speaker device in which a conventional speaker is incorporated in a closed box, and the present embodiment (shown by a solid line) has a lower resonance frequency (f) than the conventional device (shown by a broken line). ₀ ) can be reduced, and good bass reproduction can be realized.

(Embodiment 5) Next, as a speaker device, a fifth embodiment of the present invention will be described with reference to FIGS. First, in FIG. 8, 52 is a speaker,
Reference numeral 55 denotes a bass reflex box having a bass reflex port 56. FIG. 9 is an equivalent circuit diagram of the speaker device. A box mechanical resistance 57, a box compliance 58, an acoustic converter 59, a bass reflex port 56 when a bass reflex box 55 is used in the equivalent circuit of the speaker shown in FIG.
The additional mass 60 and the radiation resistance 61 are inserted.

Also in this configuration, the bass reflex box 55
, The rise of the lowest resonance frequency (f ₀ ) is suppressed, and good bass reproduction can be achieved.

[0044]

As described above, the present invention suppresses the rise of the lowest resonance frequency (f ₀ ) and realizes good reproduction of the low-frequency range even when incorporated in a small-capacity box with at least two diaphragms. Can be done.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a speaker according to a first embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of the speaker according to the embodiment.

FIG. 3 is a sectional view showing a configuration of a speaker according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a configuration of a speaker according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing a configuration of a speaker according to a fourth embodiment of the present invention.

FIG. 6 is an equivalent circuit diagram of the speaker device.

FIG. 7 is a frequency characteristic diagram of the speaker device and a conventional speaker device.

FIG. 8 is a sectional view showing a configuration of a speaker device according to a fifth embodiment of the present invention.

FIG. 9 is an equivalent circuit diagram of the speaker device.

FIG. 10 is a sectional view showing a configuration of a conventional speaker.

FIG. 11 is an equivalent circuit diagram of a conventional speaker.

[Explanation of symbols]

 22 Magnetic Circuit 27 Frame 28 Edge 29 Front Diaphragm 30 Edge 31 Rear Vibration Plate 32 Magnetic Gap 33 Voice Coil 34 Space 35 Damper

Claims (7)

[Claims] A frame coupled to a magnetic circuit is provided with at least two diaphragms each having a peripheral portion coupled thereto, and the area of a rear-side diaphragm relative to a front-side diaphragm is determined as the at least two diaphragms. A loudspeaker in which a voice coil is fitted to the diaphragm and fitted into the magnetic gap of the magnetic circuit. 2. The speaker according to claim 1, wherein a space formed between at least two diaphragms is sealed. 3. The loudspeaker according to claim 1, wherein at least two diaphragms are respectively directly connected to the voice coil. 4. The loudspeaker according to claim 1, wherein, of the at least two diaphragms, the rear diaphragm is coupled to the voice coil, and the front diaphragm is coupled to the rear diaphragm. 5. The loudspeaker according to claim 1, wherein a diaphragm for a high-frequency range different from said at least two diaphragms is connected to the voice coil. 6. A speaker device in which the speaker according to claim 1 is incorporated in a closed box. 7. A speaker device comprising the speaker according to claim 1 incorporated in a bass reflex box.