JPH03129998A - Speaker device - Google Patents

Abstract

PURPOSE:To execute effective acoustic reproduction over a wide frequency band including a low frequency band by forming a part of a speaker storing part by an acoustic resistor and connecting the inside of the speaker storing part to the inside of an outer case body through an air duct. CONSTITUTION:The speaker device is provided with a speaker unit 1 and the outer case body 2 having the speaker storing part 4 covering the rear side of the speaker unit 1 and storing and supporting the front side of the unit 1 so as to direct the front side to the outside. A part of the speaker storing part 4 is formed by the acoustic resistor 5 and the inside of the storing part 4 is connected to the inside of the outer case body 2 through the air duct 7. Thereby, the resonance frequency and attenuation characteristics of the inside of the outer case body 2 are reduced by the resistor 5 and the air duct 7 and the resonance peak of the low frequency band is suppressed. Consequently, effective acoustic reproduction can be executed over the wide frequency band including the low frequency band.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a speaker device that is supplied with an audio signal and reproduces sound.

B1 Summary of the Invention The present invention provides a speaker device comprising a speaker unit and an outer casing, in which the rear side of the speaker unit is covered in the outer casing and the front side of the speaker unit is placed outward to accommodate and support the speaker. A housing section is provided, at least a part of the speaker housing section is formed of an acoustic resistor, and the inside of the speaker housing section and the outer housing are communicated through an air duct, so that the resonance frequency inside the outer housing is low. In this way, good sound reproduction can be performed over a wide frequency band including a low frequency band.

Furthermore, in the above-described speaker device, at least a part of the speaker accommodating portion is formed of an acoustic resistor, and a passive radiator is interposed between the inside of the speaker accommodating portion and the outer casing. By lowering the resonance frequency within the housing, good sound reproduction can be performed over a wide frequency band including a low frequency band.

C1 Prior Art Conventionally, a speaker device has been proposed that includes a speaker unit that is an electroacoustic transducer and is configured to reproduce sound by supplying an acoustic signal that is an electric signal to the speaker unit. .

In such a speaker device, it is radiated to the front side and the back side of the speaker unit with mutually opposite phases of IT, so it is necessary to prevent interference between these sounds. Therefore, in this speaker device, as shown in FIG. 9, the speaker unit 101 is housed and supported in a so-called closed cabinet 102 with only the front side facing outward.
The sound radiated from the back side of the cabinet 102
A type that is sealed inside is used.

In the speaker device including the cabinet 102 as described above, the acoustic characteristics of the speaker device are expressed by the resonance frequency ``.'', the damping characteristic Q0, the equivalent mass m0, the diaphragm radius a, etc. of the speaker unit 101. It is determined by the vibration characteristics and the internal volume of the cabinet 102.

That is, in such a speaker device, since the air sealed in the cabinet 102 does not exert an elastic force on the diaphragm of the speaker unit 101, the resonance frequency of this speaker device is equal to the resonance frequency f0 of the speaker unit 101. tends to be higher. Therefore, in this speaker device, in order to lower the resonant frequency to a practically acceptable level and reproduce good sound over a wide frequency band, the cabinet 202 needs to have a sufficient internal volume. be.

D1 Problems to be Solved by the Invention By the way, in an acoustic circuit that equivalently shows the acoustic characteristics of the speaker device as described above, as shown in FIG.
Above speaker unit ION: Equivalent quality IJMd
, the compliance Cd and the acoustic resistance Rd, and the compliance cb of the cabinet 102,
It is connected in series to signal #103 to form a closed loop.

Therefore, in this speaker device, if the device configuration is downsized to reduce the internal volume of the cabinet 102, the compliance cb value of the cabinet 102 cannot be made sufficient, and good sound reproduction cannot be achieved. I can't. That is, if the value of compliance cb for the cabinet 102 is not sufficient, the resonance frequency of the speaker device will be higher than the resonance frequency 10 of the speaker unit 101, and
The attenuation characteristic is also the attenuation characteristic Q0 of the speaker unit 101.
As a result, as shown in FIG. 11, the frequency characteristics of the reproduced sound have a resonance peak in the low frequency band.

Further, when the speaker unit 101 is miniaturized, the resonance frequency r and the damping characteristic Q0 of the speaker unit 101 have a resonance peak in the low frequency band /Il:
If the resonant frequency and damping characteristics of the speaker device are increased to such an extent that the resonant frequency and damping characteristics of the speaker device cannot be lowered, no matter how large the volume of the closed cabinet 102 as described above is.

Therefore, conventionally, in a speaker device with a miniaturized device configuration, the inside of the cabinet is communicated with the outside by providing multiple through holes on the rear side of the cabinet as described above, and radiation is emitted from the front side of the speaker unit. The resonance peak in the low frequency band is suppressed by causing the sound emitted from the speaker unit to interfere with the sound emitted from the rear side of the speaker unit.

However, in a speaker device that prevents resonance in the low frequency band with such a configuration, sounds with opposite phases to each other are radiated outward, and these sounds cause interference, so that all frequencies are audibly distorted. It is difficult to perform good sound reproduction across a band.

Therefore, the present invention is proposed in view of the above-mentioned circumstances, and provides a speaker device that can reproduce good sound over a wide frequency band including a low frequency band without increasing the size of the device configuration. The purpose is to provide.

E1 Means for Solving Problems In order to solve the above-mentioned problems and achieve the above objects, a speaker device according to the present invention includes a speaker unit, a back side of this speaker unit is covered, and a front side of this speaker unit is removed. an outer casing having a speaker accommodating portion that is housed and supported on one side, the speaker accommodating portion being at least partially formed of an acoustic resistor;
It is communicated with the inside of the outer casing via an air duct.

Further, the speaker device according to the present invention includes a speaker unit and an outer casing that includes a speaker housing that covers the back side of the speaker unit and stores and supports the front side of the speaker unit from the outside. The speaker accommodating portion is at least partially formed of an acoustic resistor, and a passive radiator is interposed between the inside and the outer casing.

F1 action In the speaker device according to the present invention, the acoustic resistance body constituting the speaker housing and the air duct or pansive radiator interposed between the inside of the speaker housing and the outer casing are used to increase the noise inside the outer casing. The resonant frequency and damping characteristics are lowered, and a resonant peak in the low frequency band is observed.

G. Examples Specific examples of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the speaker device according to the present invention provides an electric sound W in which an acoustic signal, which is an electric signal, is supplied via a power supply line (not shown) and converts the acoustic signal into sound.
The speaker unit 1 includes a speaker unit 1 which is a converter, and an outer cabinet 2 which is an outer casing to which the speaker unit 1 is attached.

The subica unit (1) has a substantially disk-shaped diaphragm, and is configured to vibrate the diaphragm and radiate sound to the front side and the back side.

The outer cabinet 2 is made of a predetermined material such as synthetic resin or wood, and has a sound emitting port 2a through which a diaphragm surface on the front side of the speaker unit 1 faces outward. That is, the above speaker unit) 1
The inside of the outer periphery is joined to the periphery of the sound emitting port 2a,
It is housed and supported within the outer cabinet 2.

The outer cabinet 2 is formed in such a size that the compliance cb within the outer cabinet 2, which is determined by the internal volume, becomes a predetermined value in the acoustic circuit described later with reference to FIG.

Further, a net member 2b formed in a net shape from a material such as synthetic resin or metal is attached to the outer cabinet 2 so as to cover the diaphragm on the front side of the speaker unit (I).

In the outer cabinet 2, there is provided a speaker housing section 4 which is constituted by the outer cabinet 3 and an acoustic resistance member 5 serving as an acoustic resistance body.

The outer cabinet 3 is made of the same material as the outer cabinet 2, and is attached to the outer cabinet 2 so as to cover the speaker unit 1 from the back side. That is, the inner cabinet 3 is formed to a size that can accommodate the speaker unit 1, and the front side corresponding to the front side of the speaker unit 1 is open. The front end 3a of the inner cabinet 3 is joined to and supported by the outer circumferential side of the sound emitting port 2a in the outer cabinet 2. This inner cabinet 3 has a plurality of transparent elements on a rear surface part 3b facing the rear side of the speaker unit 1, so that the sound emitted from the rear side of the speaker unit 1 can be appropriately released to the rear side. A hole 3d is bored.

The acoustic resistance member 5 is made of a sound-absorbing material such as urethane foam or cotton, and is interposed between the rear side of the speaker unit 1 and the rear surface portion 3b of the inner cabinet 3. There is. That is, inside the speaker housing section 4, the acoustic resistance member 5 is
It communicates with the inside of the outer cabinet 2 via.

Note that the internal volume of the speaker storage section 4 is set to a predetermined value so that the compliance Ct for the inside of the speaker storage section 4 is smaller than the compliance Cd for the speaker unit 1 in the acoustic circuit described later with reference to FIG. It is formed smaller than its volume.

Furthermore, an opening 6 is formed in the inner cabinet 3 at a side surface 3C facing the side surface of the speaker unit 1. An air duct 7 is integrally provided in the inner cabinet 3 so as to extend from the opening 6. That is, the inside of the speaker storage section 4 is communicated with the inside of the outer cabinet 2 via the air duct 7. This air duct 7
is formed to be bent rearward from the side surface 3C of the inner cabinet 3, and the open end that fits into the outer cabinet 2 is directed rearward.

The air duct 7 is formed to have a size such that the air within the air duct 7 has a desired equivalent mass ML in the acoustic circuit described later with reference to FIG. The air duct 7 may be formed into a right cylindrical shape without being bent, as long as the air within the air duct 7 has a desired equivalent quality i1Mt.

As shown in FIG. 3, an acoustic circuit equivalently showing the acoustic characteristics of the speaker device according to the present invention configured as described above has the equivalent lllMd for the speaker unit 1,
Compliance Cd, acoustic resistance Rd, compliance cb of the outer cabinet 2, and acoustic resistance RL of the acoustic resistance member 5 are connected in series to the signal source S to form a closed loop. An equivalent mass gate in the air duct 7 is connected in parallel to the acoustic resistance Rt. Further, the compliance Ct for the inside of the speaker storage section 4 is connected in parallel to the acoustic resistance R[, the equivalent X iJtMt, and the compliance cb.

In this acoustic circuit, as described above, the compliance Ct within the speaker storage section 4 is smaller than the compliance Cd for the speaker unit l, so the resonant frequency 11 of this speaker device is the resonance frequency for the speaker unit l. It is lower than the frequency f0.

Further, the attenuation characteristic Q of this speaker device is the attenuation characteristic Q of the above-mentioned speaker unit 1.

has been made lower than that. Therefore, the frequency characteristics of the sound reproduced by this speaker device are as shown in Fig. 4.
The resonance peak in the low frequency band is suppressed to a low level. Therefore, in this speaker device,
Good sound reproduction can be performed over a wide frequency band including a low frequency band without increasing the size of the device configuration, that is, without changing the compliance cb of the outer cabinet 2.

In the above-described speaker device, if the entire inner cabinet 3 is made of a material with appropriate sound absorption properties, such as a sintered material made of synthetic resin such as polyethylene, the entire inner cabinet 3 will be acoustically sound. Since it plays the role of a resistor, the speaker storage section 4 is configured without providing the through hole 3d and the acoustic resistance member 5, and it is possible to perform good sound reproduction similarly to the above-described speaker device.

The speaker device according to the present invention is not limited to the above embodiment, but as shown in FIG. 5, the outer cabinet 2 is provided with a bass reflex duct 8 that communicates the inside of the outer cabinet 2 with the outside. may be configured. The bass reflex duct 8 is formed into a cylindrical shape with both ends open, and extends inward of the outer cabinet 2 in correspondence with the bass reflex opening 8a bored in the front side of the outer cabinet 2. It is integrally formed with the outer cabinet 2 as shown in FIG.

As shown in FIG. 6, an acoustic circuit that equivalently shows the ffv characteristics of the speaker device provided with the bass reflex duct 8 has an equivalent i for the speaker unit 1.
1 [iMcl, Compliance Cd.

The acoustic resistance Rd, the compliance cb of the outer cabinet 2, and the acoustic resistance Rt of the acoustic resistance member 5 are connected in series to the signal source S to form a closed loop. An equivalent mass 11Mt for the inside of the air duct 7 is connected in parallel to the acoustic resistance Rt. Further, the compliance Ct for the inside of the speaker storage section 4 is connected in parallel to the acoustic resistance R1, the equivalent one total, and the compliance cb. Furthermore, the equivalent mass Mp within the bass reflex duct 8 is connected in parallel to the compliance cb.

Also in this speaker device, the resonance frequency 11 of this speaker device is made lower than the resonance frequency f0 of the speaker unit 1, and the damping characteristic Q of this speaker device is lower than the damping characteristic Q0 of the speaker unit 1. This makes it possible to perform good sound reproduction in a wide frequency band including a low frequency band without increasing the size of the device configuration.

Further, as shown in FIG. 7, the speaker device according to the present invention allows the inside of the speaker storage section 4 to communicate with the inside of the outer cabinet 2 via the acoustic resistance member 5, and the inside of the inside cabinet 3. A passive radiator 9 having a diaphragm may be attached, and the passive radiator 9 may be interposed between the speaker storage section 4 and the outer cabinet 2. In this speaker device, the air duct 7 is not provided, and the diaphragm of the pansive radiator 9 is installed so as to close the opening 6. The pansive radiator 9 is configured so that the diaphragm is vibrated by sound radiated to the rear side of the speaker unit 1.

In this way, even in a speaker device configured using the passive radiator 9, the resonance frequency l! lr is made lower than the resonant frequency 10 of the speaker unit 1, and the damping characteristic Q of this speaker device is made lower than the damping characteristic Q0 of the speaker unit 1, thereby increasing the size of the device configuration. Good sound reproduction can be performed over a wide frequency band including a low frequency band. In addition,
Even in a speaker device constructed using this passive radiator 9, the bass reflex duct 8 may be provided in the outer cabinet 2.

Furthermore, as shown in FIG. 8, the speaker device according to the present invention allows the inside of the speaker housing section 4 to communicate with the outside through the acoustic resistance member 5 and the through hole 3d, and the speaker housing section 4 The inside of the outer cabinet 2 may be configured to be communicated with the inside of the outer cabinet 2 through an opening 6 and an air duct 7.

That is, in this speaker, the inner cabinet 3 extends rearward, and the rear surface portion 3b of the inner cabinet 3 faces outward from the rear surface side of the outer cabinet 2.

Also in the speaker device constructed by communicating the speaker storage portion 4 outwardly, the resonance frequency r1 of the speaker device is lower than the resonance frequency f0 of the speaker unit 1, and the resonance frequency r1 of the speaker device is lower than the resonance frequency f0 of the speaker unit 1. The attenuation characteristic Q of the speaker unit 1 is made lower than the attenuation characteristic Q0 of the speaker unit l. Also,
The sound radiated to the back side of the speaker unit l is
Since the sound is radiated outward through the through hole 3d and the acoustic resistance member 5, interference with the sound radiated to the front side of the speaker unit 1 is reduced. Therefore,
In this speaker device, good sound reproduction can be performed over a wide frequency band including a low frequency band without increasing the size of the device configuration.

In addition, in the speaker device in which the speaker storage portion 4 is communicated with the outside in this way, the passive radiator 9 may be attached to the bottom of the tank so as to close the opening 6 without providing the air duct 7. good. Further, even in a speaker device in which the speaker storage section 4 is communicated with the outside in this manner, the bass reflex duct 8 may be provided in the outer cabinet 2.

! 11 Effects of the Invention As mentioned above, in the speaker device according to the present invention,
The resonance frequency and damping characteristics inside the outer casing are reduced by the acoustic resistor forming at least a part of the speaker accommodating part and the air duct or passive radiator interposed in the communication part between the inside of the speaker accommodating part and the outer casing. This suppresses the resonance peak in the low frequency band.

Therefore, in this speaker device, sound reproduction in the low frequency band can be performed satisfactorily without increasing the volume of the outer casing.

In other words, the present invention eliminates the need to increase the size of equipment usurpation.
It is possible to provide a speaker device that can reproduce sound well over a wide frequency band including a low frequency band.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing the configuration of the speaker device according to the present invention as seen from the side, FIG. 2 is a vertical cross-sectional view showing the configuration of the speaker device as seen from the back side, and FIG. is an acoustic circuit equivalently showing the acoustic characteristics of the above speaker device, and FIG. 4 is a graph showing the frequency characteristics of reproduced sound of the above speaker device. FIG. 5 is a longitudinal cross-sectional view of the speaker device according to the present invention configured with a bass reflex duct, as seen from the side, and FIG. 6 shows equivalent acoustic characteristics of the speaker device configured with a bass reflex duct. This is the acoustic circuit shown in . FIG. 7 is a longitudinal cross-sectional view of a speaker device according to the present invention constructed using a pansive radiator, viewed from the side. FIG. 8 is a longitudinal cross-sectional view of the speaker device according to the present invention, which is configured with a speaker storage portion communicating with the outside, as viewed from the side. FIG. 9 is a vertical cross-sectional view showing the configuration of the conventional speaker device, FIG. 10 is an acoustic circuit equivalently showing the acoustic characteristics of the conventional speaker device, and FIG. 11 is a longitudinal cross-sectional view showing the configuration of the conventional speaker device. It is a graph showing frequency characteristics of reproduced sound. 1 ・・・・・・・・・・・・・・・ 2・・・・・・・・・・・・・・・ 3・・・・・・・・・・・・・・・ 4・・・・・・・・・・・・・・・・・・・ 5・・・・・・・・・・・・ Speaker unit outer cabinet Inner cubicle speaker storage area acoustic resistance member 7...・・・・・・・・・ Air duct 9・・・・・・・・・・・・ Passive radiator

Claims (2)

[Claims] (1) comprising a speaker unit and an outer casing having a speaker housing that covers the rear side of the speaker unit and stores and supports the speaker unit so that the front side of the speaker unit faces outward; A speaker device, at least a portion of which is formed of an acoustic resistor, and which is communicated within the outer casing via an air duct. (2) comprising a speaker unit and an outer casing having a speaker housing that covers the back side of the speaker unit and stores and supports the speaker unit with the front side facing outward; A speaker device, at least a part of which is formed of an acoustic resistor, and a passive radiator is interposed between the inside and the outer casing.