JP2014007554A - Speaker device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker device capable of attaining miniaturization while suppressing vibration.SOLUTION: A cabinet includes a front side baffle plate and a back side baffle plate that mutually face, where n (n is an integer of two or more) front side speaker units are attached to the front side baffle plate and n back side speaker units are attached to the back side baffle plate. A supply unit supplies the same signal at the same phase to the n front side speaker units and the n back side speaker units. The n front side speaker units and the n back side speaker units are arranged to be mutually deviated in two-dimensional arrangement when viewed from a sound output direction to thereby shorten a distance between the front side baffle plate and the back side baffle plate.

Description

The present invention relates to a speaker device that suppresses vibration.

  When an acoustic signal is reproduced by the speaker device, vibration is generated along with sound, and the sound is transmitted to the housing, floor, wall, etc. of the speaker device, and the sound quality may be impaired. In particular, in a speaker device that reproduces a low frequency range, the mass of a vibrating member such as a diaphragm is large, and the movement of the center of gravity due to the vibration is large, so that vibration often increases.

  In order to suppress such vibration of the speaker device, there is known a speaker device in which two speaker units are mounted in opposite directions and driven in the same phase (for example, see Patent Document 1).

JP 2006-352367 A

  In the speaker device described in Patent Document 1, a pair of speaker units are attached to a speaker box with sound emission directions opposite to each other. Therefore, the vibrations from the respective speaker units cancel each other and the vibrations are suppressed.

  However, when a pair of speaker units are attached in this manner, the thickness of the two speaker units is required, so that the speaker device is increased in size. As described above, the conventional speaker device has a problem that the speaker device becomes large when vibration is suppressed.

  Therefore, the problem to be solved by the present invention is to provide a speaker device capable of suppressing vibration and miniaturizing.

In order to solve the above problems, the present invention provides the following apparatus.
1) Enclosure (10) having a front baffle plate (102) and a back baffle plate (103) facing each other, and n (n is an integer of 2 or more) front surfaces attached to the front baffle plate Side speaker unit (101a, 101b), n back side speaker units (101c, 101d) attached to the back side baffle plate, input unit (31) for inputting an acoustic signal, and n front side speakers A supply unit (32) for supplying an acoustic signal input to the input unit to the unit and the n back side speaker units in the same phase, and includes n front side speaker units and n back side speaker units. Are arranged at positions where the vibrations of the n front speaker units and the vibrations of the n rear speaker units cancel each other. Both as to shorten the distance between the front side baffle plate of the enclosure and the rear side baffle plate, the speaker device, characterized in that arranged at positions offset from each other a two-dimensional arrangement when viewed from the output direction of the sound.
2) n front side speaker units and n back side speaker units so that vibrations by n front side speaker units and n back side speaker units are on the same straight line and in opposite directions. And the speaker device according to 1).
3) The speaker device according to 1), wherein a duct (504) that connects the inside and outside of the enclosure (50) and emits sound inside the enclosure is provided.
4) The cabinet (61) covering the enclosure (60) and the duct (604) for connecting the inside and outside of the cabinet and emitting sound inside the cabinet are provided. Speaker device.
5) The speaker device according to 4), further including a duct (605) that connects the inside of the enclosure (60) and the outside of the cabinet (61) and emits sound inside the enclosure.
6) A duct (604) that emits sound inside the cabinet (61) and a duct (605) that emits sound inside the enclosure (60) are slit-like ducts arranged on substantially the same straight line. 5) The speaker device according to 5).
7) The supply unit (72) sets the phase of the signal supplied to the n back side speaker units (101c, 101d) to the input unit to the acoustic signal supplied to the n front side speaker units (101a, 101b). The speaker device according to any one of 1) to 6), wherein the speaker device is delayed in accordance with the frequency of the acoustic signal input to.

  According to the speaker device of the present invention, it is possible to provide a speaker device that can be reduced in size while suppressing vibration.

It is a perspective view of 1st Example of the speaker apparatus of this invention. It is a schematic diagram which shows arrangement | positioning of the speaker unit of 1st Example of the speaker apparatus of this invention. It is a block block diagram of the 1st-3rd Example of the speaker apparatus of this invention. It is a schematic diagram which shows the vibration of the 1st-3rd Example of the speaker apparatus of this invention. It is a perspective view of 2nd Example of the speaker apparatus of this invention. It is a perspective view of 3rd Example of the speaker apparatus of this invention. It is a block block diagram of 4th Example of the speaker apparatus of this invention.

  Hereinafter, a speaker device of the present invention will be described based on an embodiment with reference to the accompanying drawings.

[First embodiment]
<Configuration>
FIG. 1 is a perspective view showing a speaker device 1 according to a first embodiment of the present invention. In FIG. 1, for easy understanding, the circuit portion of the speaker device 1 is not shown, and only the arrangement of the enclosure and the speaker unit is shown.

  In FIG. 1, reference numeral 10 denotes a rectangular parallelepiped enclosure that is flat in the sound output direction. N (n is an integer of 2 or more) front speaker units are arranged on the front baffle plate 102 of the enclosure 10. In this embodiment, n = 2 and two front speaker units 101a and 101b are arranged. Specifically, when the arrow A is the central axis of the speaker device 1, the center of the diaphragm is positioned so that the front speaker unit 101 a and the front speaker unit 101 b are symmetric with respect to A up and down. The front baffle plate 102 is disposed.

  Similarly, n (two in this embodiment) rear speaker units 101c and 101d are arranged on the rear baffle plate 103 facing the front baffle plate 102 of the enclosure 10. The rear-side speaker unit 101c and the rear-side speaker unit 101d are arranged so that the center of the diaphragm comes to a position that is symmetrical left and right about A. The front-side speaker units 101a and 101b and the rear-side speaker units 101c and 101d are all speaker units having the same characteristics with substantially the same aperture and substantially the same frequency characteristics.

FIG. 2 shows a two-dimensional arrangement of the front speaker units 101a and 101b and the rear speaker units 101c and 101d when viewed from the direction of the central axis A. As shown in FIG. 2, the front speaker units 101 a and 101 b are arranged vertically with respect to the central axis A, and the rear speaker units 101 c and 101 d are arranged right and left with respect to the central axis A. Thus, the front speaker units 101a and 101b and the rear speaker units 101c and 101d are arranged so as not to overlap each other when viewed from the direction of the central axis A. Thereby, the space | interval of the front side baffle board 102 and the back side baffle board 103 of the enclosure 10 can be shortened, and the speaker apparatus 1 can be reduced in size. In general, the diameter of the voice coil or magnet on the back side of the speaker unit is often smaller than the diameter of the cone paper on the sound output side, so that the voice coil or magnet does not interfere with the speaker unit. If the two-dimensional arrangement is slightly overlapped, the speaker device 1 can be miniaturized by shortening the distance between the front baffle plate 102 and the back baffle plate 103.
<Action>
FIG. 3 is a block diagram of the speaker device 1. As shown in FIG. 3, the input unit 31 sends the input acoustic signal to the supply unit 32. The supply unit 32 supplies the acoustic signal sent from the input unit 31 to the front speaker units 101a and 101b and the rear speaker units 101c and 101d in the same phase.

  FIG. 4 is a diagram showing the magnitude and direction of vibrations generated by the front speaker units 101a and 101b and the rear speaker units 101c and 101d. Arrows B and C in FIG. 4 indicate the magnitude and direction of vibration when the same signal having the positive phase is applied to each speaker unit. In FIG. 4, b is the center of gravity of the vibrating object such as cone paper or voice coil of the two front side speaker units 101a and 101b. An arrow A is the central axis of the speaker device 1 as in FIG. An arrow B indicates the magnitude and direction of vibration when the vibrations of the vibrating objects of the two front speaker units 101a and 101b are combined. c is the center of gravity of the vibrating object such as cone paper or voice coil of the two rear speaker units 101c and 101d. An arrow C indicates the magnitude and direction of the vibration when the magnitude and direction of the vibration when the vibrations of the vibrating objects of the two rear speaker units 101c and 101d are synthesized. As can be seen from FIG. 4, the arrow B and the arrow C are both on the central axis A and have the same size and opposite directions. Therefore, the vibration of the vibrating object of the front speaker units 101a and 101b and the vibration of the vibrating object of the rear speaker units 101c and 101d cancel each other. Thereby, the speaker apparatus 1 of 1st Example can be reduced in size, suppressing a vibration.

[Second Embodiment]
<Configuration>
Next, the speaker device of the second embodiment will be described. The speaker device 5 of the second embodiment is such that a duct is provided on the front baffle plate of the enclosure, and other parts are the same as those of the speaker device of the first embodiment.

  FIG. 5 is a perspective view showing a speaker device 5 according to a second embodiment of the present invention. As in FIG. 1, for ease of understanding, the circuit portion of the speaker device 5 is not shown, and only the arrangement of the enclosure and the speaker unit is shown.

  In FIG. 5, front speaker units 101 a and 101 b are arranged on the front baffle plate 502 of the enclosure 50, and rear speaker units 101 c and 101 d are arranged on the rear baffle plate 503 of the enclosure 50. The front-side speaker units 101a and 101b and the rear-side speaker units 101c and 101d are the same speaker units as those in the first embodiment, the arrangement is the same as in the first embodiment, and the block configuration diagram is also the same as in the first embodiment. In the speaker device 5 of the second embodiment, a duct 504 is further provided in the front baffle plate 502 of the enclosure 50. The duct 504 has a predetermined length set so that sound in a frequency band mainly reproduced by the speaker device 5 resonates, and connects the inside and the outside of the enclosure 50.

In general, a container having an opening and storing gas is called a Helmholtz resonator, and the resonance frequency is expressed by the following equation.
f = (v / 2π) × √ [S / [V (L + δ)]] Formula (1)
Where f: Helmholtz resonance frequency (Hz)
v: speed of sound (m / s)
S: Duct cross-sectional area (m ² )
V: Contents of the box (m ³ )
L: Duct length (m)
δ: Open end length correction (m)
However, when r = √ (S / π), δ = 0.6r
When the duct 504 of the present embodiment is calculated by the equation (1), for example, V = 0.06 × 0.3 × 0.4 = 7.2 × 10 ⁻³ (m ³ )
v = 340 (m / s)
S = 0.025 × 0.025 × π = 1.96 × 10 ⁻³ (m ² )
L = 0.25 (m)
F = 54.9 (Hz)
It becomes. Low-frequency bass reflex speakers often have a resonance frequency set to 10 Hz to several tens of Hz, so it is preferable to set such a value.
<Action>
In the speaker device 5 of the second embodiment, the sound inside the enclosure 50 resonates and is emitted to the outside through the duct 504. Thereby, like the speaker device of the first embodiment, it is possible to reduce the size while suppressing the vibration, and to output a larger sound.

[Third embodiment]
<Configuration>
Next, a speaker device according to a third embodiment will be described. The speaker device 6 of the third embodiment is provided with a cabinet outside the enclosure, and the other parts are the same as those of the speaker device of the second embodiment.

  FIG. 6 is a perspective view showing a speaker device 6 according to a third embodiment of the present invention. As in FIGS. 1 and 5, for ease of understanding, the circuit portion of the speaker device 6 is not shown, and only the arrangement of the cabinet, the enclosure, and the speaker unit is shown.

  In FIG. 6, front speaker units 101 a and 101 b are arranged on the front baffle plate 602 of the enclosure 60, and rear speaker units 101 c and 101 d are arranged on the rear baffle plate 603 of the enclosure 60. The front speaker units 101a and 101b and the rear speaker units 101c and 101d are the same speaker units as those in the first and second embodiments and are arranged in the same manner, and the block diagram is the same as those in the first and second embodiments. . In the speaker device 6 of the third embodiment, a cabinet 61 is provided outside the enclosure 60, and a slit-like duct 604 is provided in the cabinet 61. Similar to the second embodiment, the duct 604 has a predetermined length set so that sound in a frequency band mainly reproduced by the speaker device 6 resonates, and connects the inside and the outside of the cabinet 61.

In the speaker device 6, a duct 605 is provided on the front baffle plate 602 of the enclosure 60. The duct 605 penetrates the cabinet 61 and connects the inside of the enclosure 60 and the outside of the cabinet 61, and emits sound inside the enclosure 60 to the outside. FIG. 6 shows an example in which a slit-like duct 605 extending left and right is provided at the center of the front baffle plate 602. In this case, the length of the duct 605 cannot be sufficiently secured, but the duct 604 and the duct 605 can be arranged on the substantially same straight line by making the sound outlet into a slit shape. Such a speaker device 6 can be installed by embedding it in the wall only by providing one slit in the wall and exposing the duct 604 and the duct 605 from the slit provided in the wall.
<Action>
The speaker device 6 according to the third embodiment is provided with a cabinet 61, so that sound output from the rear speaker units 101c and 101d to the back and output from the front speaker units 101a and 101b to the front are output. Sound resonates in the cabinet 61. Further, the sound once resonated in the cabinet 61 is emitted from the duct 604.

Further, since the duct 605 of the enclosure 60 is connected to the outside of the cabinet 61, the sound inside the enclosure 60 is emitted to the outside through the duct 605.
As described above, in the speaker device 6 of the third embodiment, the sound output from the front speaker units 101a and 101b and the rear speaker units 101c and 101d is emitted to the outside through the duct 604, and the enclosure 60 Sound inside is released through the duct 605 to the outside. Therefore, like this, like the speaker device of the first embodiment, it is possible to reduce the size while suppressing the vibration, and to output a larger sound. Furthermore, the speaker device 6 can be embedded in the wall by providing one slit on the wall and exposing the duct 604 and the duct 605 from the slit provided on the wall, thereby making the speaker device 6 inconspicuous.

  Architectural designers tend to think that speaker devices are not suitable as interiors, so it has been desired to embed speaker devices in walls. However, in general stores and houses, the wall thickness is not so thick and the vibration shielding is often not sufficient. Conventional speaker devices are thick and difficult to embed in walls. Furthermore, when it was embedded in the wall, the vibration of the speaker device was transmitted, the sound became muddy and the sound quality deteriorated. On the other hand, the speaker device of this embodiment can be thinned and can be embedded in a wall. Further, since the sound outlet is slit-shaped, it is only necessary to provide a slit in the wall, and the presence of the speaker device can be made inconspicuous. Furthermore, since the vibration is suppressed, the sound quality is not deteriorated.

[Fourth embodiment]
<Configuration>
Next, a speaker device according to a fourth embodiment will be described. The speaker device 7 of the fourth embodiment is the same as the first embodiment except that the supply unit of the speaker device of the first embodiment is changed.

    FIG. 7 shows a block diagram of the speaker device 7. The acoustic signal input to the input unit 71 is sent to the supply unit 72. The supply unit 72 includes a phase shift unit 701, a power amplification unit A 702a, and a power amplification unit B 702b. The acoustic signal input to the input unit 71 is amplified by the power amplification unit A 702a and supplied to the front speaker units 101a and 101b. Further, the acoustic signal input to the input unit 71 is simultaneously supplied to the phase shift unit 701, and the phase is shifted by the phase shift unit 701. The phase shift unit 701 is a one-stage all-pass filter including, for example, an operational amplifier, a resistor, and a capacitor. The acoustic signal whose phase is shifted by the phase shifter 701 is amplified by the power amplifier B702b and supplied to the rear speaker units 101c and 101d. In the example of FIG. 7, the phase is changed by a phase shift unit 701 provided in front of the power amplification unit B 702b, amplified by two independent power amplification units, and supplied to two sets of speaker units. On the other hand, after amplifying by one power amplification unit, the phase of the two speaker units may be changed by changing the phase using an LC circuit or the like before the speaker unit.

  The phase shift unit 701 changes the phase delay amount according to the frequency of the input acoustic signal. In this embodiment, the constants of the resistor and the capacitor are such that the phase delay amount is 30 ° or less for an input acoustic signal having a frequency of 25 Hz or more, and the phase delay amount is less than an input acoustic signal having a frequency lower than 25 Hz. It is set to be larger than 30 °.

Note that the phase shift unit 701 shown in FIG. 7 allows the all-pass filter to pass through one stage, but the number of stages may be increased as necessary, or the phase may be shifted by a low-pass filter or digital signal processing. Further, a phase shift with a reverse characteristic may be performed on the power amplification unit A side.
<Action>
When an acoustic signal having a frequency lower than 25 Hz is input to the input unit 70, the power amplification unit A 702a amplifies and supplies the amplified signal to the front speaker units 101a and 101b, and the phase shift unit 701 delays the phase by more than 30 °. Then, it is amplified by the power amplifier B702b and supplied to the rear speaker units 101c and 101d. Now, assuming that 25 Hz is below the reproduction limit frequency of the speaker unit, the speaker device 7 does not output as sound, but vibration occurs. Since the phase lag is large, the vibrations of the front speaker unit and the rear speaker unit are not canceled each other, and the vibrations are generated. Vibration with a frequency below the reproduction limit frequency does not make the sound cloudy. On the other hand, since such low-frequency vibrations are transmitted to walls and floors, the vibrations can be experienced, thereby improving the deep bass feeling.

  Humans detect air vibrations and secondary vibrations caused by sound everywhere in the body. For example, the detection of vibrations by tactile sensation of the skin has a lower frequency band than the detection of sound by the eardrum. Are known. Therefore, by generating vibrations in a low frequency band below the reproduction limit frequency, it is possible to improve the heavy bass feeling due to tactile sensation.

  On the other hand, for an acoustic signal in a reproducible frequency band, the phase delay is 30 ° or less, and the vibrations of the front speaker unit and the rear speaker unit cancel each other. Thereby, like the first to third embodiments, vibration can be suppressed and sound turbidity can be prevented.

  Thus, the speaker device of the present embodiment can be miniaturized while suppressing vibrations, and can further improve the deep bass feeling.

  In the speaker devices of the second and third embodiments, the phase can be changed by replacing the supply section 32 with the supply section 72 of the fourth embodiment, and the fourth embodiment described above. Has the same effect as.

1, 5, 6 Speaker device 10, 50, 60 Enclosure 101a, 101b Front side speaker unit 101c, 101d Rear side speaker unit 102, 502, 602 Front side baffle plate 103, 503, 603 Rear side baffle plate 31, 71 Input section 32, 72 Supply unit 504, 604, 605 Duct 61 Cabinet 701 Phase shift unit 702a Power amplification unit A
702b Power amplification part B

Claims (7)

An enclosure having a front baffle plate and a back baffle plate facing each other;
N (n is an integer of 2 or more) front side speaker units attached to the front side baffle plate;
N back side speaker units attached to the back side baffle plate;
An input unit for inputting an acoustic signal;
A supply unit that supplies the acoustic signals input to the input unit to the n front speaker units and the n rear speaker units in the same phase;
The n number of front side speaker units and the n number of back side speaker units are arranged at positions where vibrations by the n number of front side speaker units and vibrations by the n number of back side speaker units cancel each other. And the two-dimensional arrangement when viewed from the sound output direction is shifted from each other so as to shorten the distance between the front baffle plate and the rear baffle plate of the enclosure. A speaker device. The n front speaker units and the n back sides are so arranged that vibrations by the n front speaker units and vibrations by the n back speaker units are on the same straight line and in opposite directions. The speaker device according to claim 1, further comprising a speaker unit.   The speaker device according to claim 1, further comprising a duct that connects the inside and the outside of the enclosure and emits sound inside the enclosure. A cabinet covering the enclosure;
The speaker device according to claim 1, further comprising a duct that connects the inside and the outside of the cabinet and emits sound inside the cabinet.   The speaker device according to claim 4, further comprising a duct that connects the inside of the enclosure and the outside of the cabinet and emits sound inside the enclosure.   6. The speaker according to claim 5, wherein the duct that emits sound inside the cabinet and the duct that emits sound inside the enclosure are slit-like ducts arranged on substantially the same straight line. apparatus. The supply unit is configured to change a phase of a signal supplied to the n back side speaker units with respect to an acoustic signal supplied to the n number of front side speaker units according to a frequency of the acoustic signal input to the input unit. The speaker device according to claim 1, wherein the speaker device is delayed.