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JP2013012991

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Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2013012991
Abstract: To provide a speaker device whose directivity can be easily changed. A first speaker
unit (101) faces a diaphragm to the outside of a speaker device. The second speaker unit 102
faces the diaphragm outward, and is separated from the first speaker unit by a distance d of 0.17
m or more and less than 0.476 m in the first direction. The third speaker unit 103 has the
diaphragm directed outward, and is separated from the first speaker unit by a distance d in a
second direction orthogonal to the first direction. The fourth speaker unit 104 faces the
diaphragm outward, and is separated from the second speaker unit by a distance d in the second
direction. The supply unit 21 supplies an audio signal to the first speaker unit, and selectively
reverses the phase of the audio signal to supply the second speaker unit, the third speaker unit,
and the fourth speaker unit. Do. [Selected figure] Figure 1
Speaker device
[0001]
The present invention relates to a speaker device whose directivity can be changed.
[0002]
In public facilities such as stations and large-scale stores, commercial facilities, etc., PAs (Public
Address, broadcasting equipment) providing guidance broadcasting by voice are widely used.
In PA, when the guidance broadcast reaches the outside of the facility, it becomes a noise, so a
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speaker device having directivity is used so that the guidance broadcast can reach only the target
area.
[0003]
As a speaker device having directivity, there is known a dipole speaker device in which speaker
units having the same performance are provided on opposing baffle surfaces of a cabinet and
driven in opposite phase (for example, see Patent Document 1).
[0004]
Also, as a speaker device having directivity, there is also known a tone zone speaker in which a
plurality of speakers are linearly arranged.
(For example, refer to Patent Document 2).
[0005]
JP-A-8-19089 JP-A-2-239795
[0006]
By the way, depending on the installation place of the speaker device, there are cases where it is
desired to change the place where the voice of the guidance broadcast is transmitted.
For example, in a speaker apparatus installed in a hall, depending on the usage condition of the
hall, the place where the voice of the guidance broadcast is desired to be changed may be
desired, or the voice of the guidance broadcast may be desired to be transmitted to the entire
hall.
[0007]
However, the speaker devices of Patent Document 1 and Patent Document 2 can not easily
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change directivity. Therefore, there is a problem that when it is desired to change the location
where the voice of the guidance broadcast is to be transmitted, the installation direction of the
speaker device has to be changed or a new speaker device has to be added.
[0008]
Therefore, the problem to be solved by the present invention is to provide a speaker device
whose directivity can be easily changed.
[0009]
In order to solve the above problems, the present invention provides the following apparatus.
1) In the speaker device for amplifying an audio signal, the speaker device is a first speaker unit
(101) whose diaphragm is directed to the outside of the speaker device and a speaker unit whose
diaphragm is directed to the outside of the speaker device A second speaker unit (102) in which
the distance between the center of the first speaker unit and the diaphragm in the first direction
is separated by a distance of 0.17 m or more and less than 0.41 m, and the diaphragm outside
the speaker device A speaker unit directed to the third speaker, wherein a distance between the
diaphragm with the first speaker unit is separated by a distance of 0.17 m or more and less than
0.41 m in a second direction orthogonal to the first direction. A speaker unit (103) and a speaker
unit having a diaphragm directed to the outside of the speaker device, the second speaker unit in
the second direction Speaker unit (104) in which the distance between the diaphragms of the
first and second diaphragm units is separated by a distance of 0.17 m or more and less than 0.41
m, and the first speaker unit, the second speaker unit, and the third speaker unit And a supply
unit (21) for supplying to the fourth speaker unit, wherein the supply unit selectively selects the
phase of the audio signal supplied to the second speaker unit, the third speaker unit, and the
fourth speaker unit. A speaker device characterized by being inverted. 2) The speaker device
according to 1), wherein the distance is 0.24 m or more and less than 0.34 m. 3) The speaker
apparatus according to 1) or 2), wherein the first speaker unit, the second speaker unit, the third
speaker unit, and the fourth speaker unit are speaker units having the same characteristics. 4) A
band division unit (51) for dividing the input acoustic signal into a plurality of frequency bands,
and at least one pair of speakers (4Bn) for outputting the acoustic signal divided by the band
division unit, and one set of speakers The first speaker unit (4Bnfr) with the diaphragm directed
to the outside of the pair of speakers, and the wavelength of the acoustic signal at the center
frequency of the frequency band output by the pair of speakers is λ, one diaphragm A speaker
unit directed to the outside of the set of speakers, wherein a second center of the diaphragm with
the first speaker unit is separated by a distance of 0.25 λ or more and less than 0.6 λ in the
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first direction. A speaker unit (4Bnfl) and a speaker unit having a diaphragm directed to the
outside of a pair of speakers, the first speaker unit extending in a second direction orthogonal to
the first direction A third speaker unit (4Bnrr) in which the distance between the diaphragms of
the first and second diaphragms is equal to or greater than 0.25.lamda. And less than 0.6.lamda.,
And the speaker unit with the diaphragms facing the outside of the pair of speakers. The first
speaker unit (4Bnrl) has a diaphragm separated from the second speaker unit by a distance of
0.17 m or more and less than 0.41 m in the direction of d. Speaker unit, a second speaker unit, a
third speaker unit and a fourth speaker unit, and a supply unit (52n) for supplying to the second
speaker unit, the third speaker unit, and the A speaker device characterized by selectively
inverting the phase of an audio signal to the 4 speaker units.
5) The speaker device according to 4), wherein the distance is set to 0.35 λ or more and less
than 0.5 λ. 6) The speaker apparatus according to 4) or 5), wherein the first speaker unit, the
second speaker unit, the third speaker unit, and the fourth speaker unit are speaker units having
the same characteristics.
[0010]
According to the speaker device of the present invention, directivity can be easily changed.
[0011]
It is a perspective view of 1st Example of the speaker apparatus of this invention.
It is a block block diagram of 1st Example of the speaker apparatus of this invention. It is a figure
which shows directivity characteristics when the space | interval d of 1st Example of the speaker
apparatus of this invention is changed. It is a 1st perspective view of 2nd Example of the speaker
apparatus of this invention. It is a block block diagram of 2nd Example of the speaker apparatus
of this invention. It is a figure which shows directional characteristics when the phase of 1st
Example of the speaker apparatus of this invention is changed. It is a 2nd perspective view of
2nd Example of the speaker apparatus of this invention.
[0012]
Hereinafter, a speaker device of the present invention will be described based on an embodiment
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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, wherein FIG. 1a) is a perspective view showing an arrangement place of a speaker unit,
and FIG. It is a perspective view which shows the state which arrange | positioned the unit. In
order to facilitate understanding, in FIG. 1a, the speaker unit is not shown, and only the
positional relationship of the place where the speaker unit is arranged is shown. Further, in FIG.
1 b), the positional relationship of the location where the speaker unit is disposed, the casing of
the speaker device 1 and the circuit portion are not shown, and only the placement of the
speaker unit is shown.
[0013]
The speaker device 1 of the present embodiment is mainly used for the purpose of loud-speaking
such as an announcement in a PA, and loud-speaks and outputs human-generated speech in a
frequency band of 250 Hz to 600 Hz with a frequency of 500 Hz as a center. Do.
[0014]
In FIG. 1, SQ is a square whose center is X and whose side is d.
The front and right vertices of the square SQ are V1, the front and left vertices are V2, the rear
and right vertices are V3, and the rear and left vertices are V4. Also, let A be the front direction
of the speaker device 1 and let D be the left direction orthogonal to A. In this embodiment, four
speaker units are arranged such that the center of the diaphragm is at the apexes V1 to V4 of the
square SQ. Specifically, the direction of the diaphragm is directed to the opposite direction of the
center point X, that is, outward with respect to the center point X, so that the center of the
diaphragm is at the position of the apex V1 on the front side and the right side. Deploy. The
direction of the diaphragm is from the vertex V2 so that the center of the diaphragm is at the
position of the apex V2 of the front side and the left side of the first speaker unit 101 separated
by the distance d in the left side of the first speaker unit 101 In this case, it is arranged in the
opposite direction of the central point X, that is, outward. In addition, the direction of the
diaphragm is from the vertex V3 so that the center of the diaphragm is at the position of the
vertex V3 on the rear side on the right side with the third speaker unit 103 separated by the
distance d in the rear direction of the first speaker unit 101 In this case, it is arranged in the
opposite direction of the central point X, that is, outward. Furthermore, the direction of the
diaphragm is from the vertex V4 so that the center of the diaphragm is at the position of the
vertex V4 on the rear side and the left side, which is the distance d in the rear direction of the
second speaker unit 102. In this case, it is arranged in the opposite direction of the central point
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X, that is, outward.
[0015]
The first speaker unit 101, the second speaker unit 102, the third speaker unit 103, and the
fourth speaker unit 104 have substantially the same aperture, and have the same characteristics
with substantially the same frequency characteristics, and are attached to the enclosure Use in a
state where the sound from the back is blocked.
[0016]
FIG. 2 is a block diagram of the speaker device 1.
As shown in FIG. 2, the input unit 20 sends the input audio signal to the supply unit 21. The
supply unit 21 supplies the audio signal sent from the input unit 20 to the first speaker unit 101,
the second speaker unit 102, the third speaker unit 103, and the fourth speaker unit 104.
[0017]
Also, as shown in FIGS. 2a), 2b) and 2c), the supply unit 21 performs the first speaker on the
phase of the audio signal supplied to the second speaker unit 102, the third speaker unit 103,
and the fourth speaker unit 104. The audio signals supplied to the unit 101 can be respectively
inverted. <Operation when the interval d is changed> In the speaker device 1 of the present
embodiment, the first speaker unit 101, the second speaker unit 102, the third speaker unit 103,
and the fourth speaker unit 104 mutually cross each other. The directivity characteristics when
the distance d between the left and right and is changed are shown in FIG. Here, as shown in FIG.
2 a), the supply unit 21 supplies the audio signal sent from the input unit 20 to the first speaker
unit 101 and the second speaker unit 102 with the same phase, and To the speaker unit 103 and
the fourth speaker unit 104, an audio signal whose phase is inverted from that of the audio
signal supplied to the first speaker unit 101 and the second speaker unit 102 is supplied.
[0018]
FIG. 3 illustrates the sound pressure of the sound wave output in each direction of the speaker
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device 1 when the reference audio signal of the wavelength λ is input to the speaker device 1,
using the speaker unit as a point sound source and showing a circle graph. It is a thing. In FIG. 3,
the interval d is represented by a multiple of λ. In the circle graph of the directivity
characteristic of FIG. 3, the downward direction is the front direction of the speaker device 1.
Further, twice the sound pressure of the sound wave of the output when the reference audio
signal is input to one speaker unit is 0 dB (maximum value of the scale of the circle graph).
[0019]
As shown in FIG. 3a), when d <0.3λ, the waveform of the directivity characteristic is a widelyspread eight-shaped, and the directivity of the speaker device 1 is low. Also, the sound pressure
in the direction of arrow A (forward direction) is about -6 dB, and the efficiency as the speaker
device 1 is low.
[0020]
As shown in FIG. 3 b), c) and d), when 0.3 λ ≦ d <0.45 λ, the waveform of the directivity
characteristic is a somewhat wide eight-shaped one, and the speaker device 1 is It has directivity.
Further, the maximum sound pressure exceeds −2 dB, and the efficiency as the speaker device 1
is high.
[0021]
As shown in FIGS. 3e), f), g) and h), when the condition of 0.45λ ≦ d <0.65λ, the waveform of
the directivity characteristic is a figure of eight, and the speaker device 1 is high in the front-rear
direction It has directivity. Further, the maximum sound pressure exceeds −2 dB, and the
efficiency as the speaker device 1 is high.
[0022]
As shown in Fig. 3i) and j), when 0.65 λ 指向 d <0.75 λ, when looking at the waveform of the
directional characteristics, although it has some side lobes, it has a figure of eight, and the
speaker The directivity of the device 1 is high. Also, the maximum sound pressure exceeds -4 dB,
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and the efficiency of the speaker device 1 is within an allowable range.
[0023]
As shown in FIGS. 3 k) and l), when the waveform of the directivity characteristic is observed
when 0.75 λ ≦ d, a large side lobe is generated, and the directivity of the speaker device 1 is
low. Further, the maximum sound pressure is −6 dB or less, and the efficiency as the speaker
device 1 is low and the practicability is inferior.
[0024]
To summarize the above, the speaker device 1 of the present embodiment has low directivity
when d <0.3λ. When 0.3 λ ≦ d <0.75 λ, directivity is given in the front-rear direction.
Furthermore, when 0.45 λ ≦ d <0.65 λ, the directivity is high in the front-rear direction, and
the efficiency is high. When 0.75 λ ≦ d, directivity is low and efficiency is low.
[0025]
Further, as described above, the speaker device 1 of the present embodiment is mainly used for
the purpose of loud-speaking such as an announcement on the PA, and outputs the sound
composed of the sound wave signal of the frequency band centered on the frequency 500 Hz. .
When the sound velocity is 340 m / s, the wavelength of the sound wave with a frequency of 500
Hz is 0.68 m. At this time, 0.3 λ ≦ d <0.75 λ corresponds to 0.204 m ≦ d <0.51 m, and 0.45
λ ≦ d <0.65 λ corresponds to 0.306 m ≦ d <0.442 m.
[0026]
The speaker device 1 of the present embodiment is characterized in that the distance d between
the front and rear speaker units is 0.17 m ≦ d <0.51 m. More preferably, 0.306 m ≦ d <0.442
m.
[0027]
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In the speaker device 1 of the present embodiment, the first speaker unit 101 and the third
speaker unit 103 constitute a dipole speaker. Similarly, the second speaker unit 102 and the
fourth speaker unit 104 constitute a dipole speaker. Some conventional dipole speaker devices
have a shielding plate to avoid interference of sound waves between the speaker units in the
front-rear direction. On the other hand, the speaker device of this embodiment outputs the audio
signals of the same phase to two speaker units in which the directions of the diaphragms are
opposite to each other, and the distance between them is approximately one of the wavelength
that becomes the center of the output. It will be / 2. As a result, the phases of the outputs of the
two speaker units become the same in the front-rear direction, and the outputs of the two
speaker units increase. Therefore, not only the shielding plate is unnecessary but also directivity
can be further enhanced.
[0028]
In addition, the first speaker unit 101 and the second speaker unit 102 constitute a tone zone
speaker. Similarly, the third speaker unit 103 and the fourth speaker unit 104 constitute a tone
zone speaker. Since the tone snail type speaker device has high directivity in the front-rear
direction with respect to a signal having a wavelength approximately twice that of the left and
right unit interval, directivity can be further improved.
[0029]
Further, the speaker device 1 of the present embodiment exhibits high directivity by using four
speaker units, and only needs to have a width in which two speaker units are arranged at an
interval of 1/2 wavelength in the lateral direction. Miniaturization is possible compared with the
conventional speaker apparatus.
[0030]
In addition, the unit intervals between the front, rear, left, and right of the speaker units are not
necessarily the same as each other as long as they are within the ranges described above.
<Operation when phase is switched> Next, in the speaker device 1 of the present embodiment,
the directional pattern when the supply unit 21 switches the phase of the audio signal supplied
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to each speaker unit, the block configuration of FIG. This will be described using the diagram and
the diagram of the directivity characteristic of FIG. Here, the distance d between the first speaker
unit 101, the second speaker unit 102, the third speaker unit 103, and the fourth speaker unit
104 is defined as λ / 2. The other conditions similar to those in FIG. 3 will not be described.
[0031]
In FIG. 2a), the supply unit 21 supplies the audio signal sent from the input unit 20 to the first
speaker unit 101 and the second speaker unit 102 in the same phase. The supply unit 21 also
supplies, to the third speaker unit 103 and the fourth speaker unit 104, an audio signal obtained
by inverting the phase of the audio signal supplied to the first speaker unit 101. The directivity
characteristic at this time is shown in FIG. This is the same as the above-mentioned FIG. 3 f), and
at this time, the speaker device 1 has high directivity in the front-rear direction as described
above.
[0032]
In FIG. 2 b), the supply unit 21 supplies the audio signal sent from the input unit 20 to the first
speaker unit 101 and the third speaker unit 103 in the same phase. The supply unit 21 also
supplies, to the second speaker unit 102 and the fourth speaker unit 104, an audio signal
obtained by inverting the phase of the audio signal supplied to the first speaker unit 101. The
directivity characteristic at this time is shown in FIG. At this time, the first speaker unit 101 and
the third speaker unit 103, the second speaker unit 102 and the fourth speaker unit 104
respectively become speakers of the tone zone system, and further, the first speaker unit 101
and the second speaker unit 102, the second The three-speaker unit 103 and the fourth speaker
unit 104 each become a dipole speaker. Therefore, as apparent from FIG. 6 b), the speaker device
1 has high directivity in the left-right direction.
[0033]
In FIG. 2 c), the supply unit 21 supplies the audio signal sent from the input unit 20 to the first
speaker unit 101 and the fourth speaker unit 104 in the same phase. The supply unit 21 also
supplies, to the second speaker unit 102 and the third speaker unit 103, an audio signal in
reverse phase to the audio signal supplied to the first speaker unit 101. The directivity
characteristic at this time is shown in FIG. At this time, since the adjacent speaker units are
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driven in opposite phases, they have a dipole characteristic, and the sound pressure in the
diagonal direction increases. As apparent from FIG. 6 c), at this time, the speaker device 1 has an
X-shaped directivity characteristic in which the sound pressure in the oblique direction is high.
[0034]
Thus, the speaker device of this embodiment can easily change the directivity by switching the
phase of the audio signal supplied to each speaker unit. Second Embodiment <Configuration>
Next, a speaker device according to a second embodiment will be described. The second
embodiment is an example of a speaker device having high directivity over a wider frequency
band than the first embodiment. The speaker apparatus 4 of the second embodiment is provided
with n sets (n is an integer of 2 or more) of speaker sets 4Bn in which the distance between the
speaker apparatus 1 of the first embodiment is changed as a set of speaker sets. It is
[0035]
Hereinafter, an example in which n = 6 is described. FIGS. 4 and 7 are perspective views showing
a second embodiment of the speaker device according to the present invention, wherein FIG. 4 is
a perspective view showing an arrangement place of the speaker unit, and FIG. 7 is a perspective
view showing a state where the speaker unit is arranged. It is. In order to facilitate
understanding, in FIG. 4, the speaker units are not shown, but only the positional relationship of
the places where the speaker units are arranged. Further, in FIG. 7, the positional relationship of
the place where the speaker unit is arranged, the casing of the speaker device 4 and the circuit
portion are not shown, and only the arrangement of the speaker unit is shown.
[0036]
In FIG. 4 and FIG. 7, SQn is a square whose center is Xn and whose one side is dn. The front and
right vertices of the square SQn are Vn1, the front and left vertices are Vn2, the rear and right
vertices are Vn3, and the rear and left vertices are Vn4. Also, let C be the front direction of the
speaker device 1 and let E be the left direction orthogonal to C. In the present embodiment, in
order to prevent overlapping of the speaker units, as shown in FIGS. 4 and 7, the squares SQ1 to
SQ6 are arranged mutually offset in the vertical direction.
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[0037]
In this embodiment, four speaker units are arranged at the vertices Vn1 to Vn4 of the square
SQn. Specifically, the direction of the diaphragm is directed to the opposite direction of the center
point Xn, that is, to the outside, as viewed from the vertex Vn1, so that the center of the
diaphragm is at the position of the apex Vn1 on the front side and the right side. Deploy. The
direction of the diaphragm is from the apex Vn2 so that the center of the diaphragm is at the
position of the apex Vn2 of the front side and the left side separated by the distance dn in the left
side of the first speaker unit 4Bnfr. In this case, they are arranged in the opposite direction of the
central point Xn, that is, outward. In addition, the direction of the diaphragm is from the vertex
Vn3 so that the center of the diaphragm is at the position of the vertex Vn3 on the rear side and
the right side away from the third speaker unit 4Bnrr by the distance dn in the rear direction of
the first speaker unit 4Bnfr In this case, they are arranged in the opposite direction of the central
point Xn, that is, outward. Furthermore, the direction of the diaphragm is from the vertex Vn4 so
that the center of the diaphragm is at the position of the vertex Vn4 on the rear side and the left
side separated by the distance dn in the back direction of the second speaker unit 4Bnfl. In this
case, they are arranged in the opposite direction of the central point Xn, that is, outward.
[0038]
In each speaker set 4Bn, speakers having the same characteristics as the first speaker unit 4Bnfr,
the second speaker unit 4Bnfl, the third speaker unit 4Bnrr, and the fourth speaker unit 4Bnrl
having substantially the same aperture and substantially the same frequency characteristics It is
used as a unit with the sound from the back cut off by attaching it to an enclosure.
[0039]
FIG. 5 is a block diagram of the speaker device 4.
As shown in FIG. 5, the input unit 50 sends the input acoustic signal to the band division unit 51.
The band division unit 51 includes n sets of BPFs (Band Pass Filters) 51 n including capacitors
and coils. The BPF 51 n divides the frequency band of the input acoustic signal, and outputs the
band-divided acoustic signal to each speaker set 4 Bn.
[0040]
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The speaker set 4Bn (4B1, 4N2, 4B3, 4B4, 4B5, 4B6) includes a supply unit 52n (521, 522, 523,
524, 525, 526) not shown. The supply unit 52n supplies the acoustic signal sent from the BPF
51n to the first speaker unit 4Bnfr, the second speaker unit 4Bnfl, the third speaker unit 4Bnrr,
and the fourth speaker unit 4Bnrl. The supply unit 52 n also performs the phase of the acoustic
signal supplied to the second speaker unit 4Bnfl, the third speaker unit 4Bnrr, and the fourth
speaker unit 4Bnrl to the phase of the acoustic signal supplied to the first speaker unit 4Bnfr.
Each can be reversed. Inversion of the phase of the acoustic signal supplied to the second
speaker unit 4Bnfl, the third speaker unit 4Bnrr, and the fourth speaker unit 4Bnrl of the supply
unit 52n is such that all the n supply units 52n are interlocked and switched Do.
[0041]
In addition, an interval dn between front and rear and left and right of each speaker unit in each
speaker set is approximately 1/2 of the wavelength of the center frequency of the acoustic signal
divided for each speaker set by the band division unit 51.
[0042]
The speaker device 4 includes a first band speaker set 4B1, a second band speaker set 4B2, a
third band speaker set 4B3, a fourth band speaker set 4B4, a fifth band speaker set 4B5, and a
sixth band speaker It is equipped with 6 sets of speaker sets 4Bn of set 4B6.
[0043]
The input unit 50 sends the input acoustic signal to the band division unit 51.
The band division unit 51 includes six sets of BPFs 511 to 516, and divides the input acoustic
signal into six frequency bands whose center frequencies differ by 1/2 octave.
[0044]
The BPF 511 outputs an acoustic signal in a frequency band of center frequency 500 Hz to the
supply unit 521 of the first band speaker set 4B1.
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The supply unit 521 transmits the acoustic signals band-divided by the BPF 511 to the first
speaker unit 4B1fr, the second speaker unit 4B1fl, the third speaker unit 4B1rr, and the fourth
speaker unit 4B1rl in a phase as described later. Supply. In addition, an interval d1 between front
and rear and left and right of the first speaker unit 4B1fr, the second speaker unit 4B1fl, the
third speaker unit 4B1rr, and the fourth speaker unit 4B1rl is a half wavelength of the acoustic
signal of the center frequency 500 Hz. It is 0.34 m.
[0045]
The BPF 512 outputs, to the supply unit 522 of the second band speaker set 4B2, an acoustic
signal of a frequency band centered on a frequency 707 Hz which is 1⁄2 octave higher than the
center frequency 500 Hz of the BPF 511. The supply unit 522 transmits the acoustic signals
band-divided by the BPF 512 to the first speaker unit 4B2fr, the second speaker unit 4B2fl, the
third speaker unit 4B2rr, and the fourth speaker unit 4B2rl in a phase as described later. Supply.
In addition, an interval d2 between front and rear and left and right of the first speaker unit
4B2fr, the second speaker unit 4B2fl, the third speaker unit 4B2rr, and the fourth speaker unit
4B2rl is a half wavelength of an acoustic signal with a center frequency of 707 Hz. There is a
certain 0.24 m.
[0046]
The BPF 513 outputs, to the supply unit 523 of the third band speaker set 4B3, an acoustic
signal of a frequency band centered on 1 kHz, which is a half octave higher than the center
frequency 707 Hz of the BPF 512. The supply unit 523 transmits the acoustic signals banddivided by the BPF 513 to the first speaker unit 4B3fr, the second speaker unit 4B3fl, the third
speaker unit 4B3rr, and the fourth speaker unit 4B3rl in a phase as described later. Supply. In
addition, the distance d3 between the front and rear and left and right of the first speaker unit
4B3fr, the second speaker unit 4B3fl, the third speaker unit 4B3rr, and the fourth speaker unit
4B3rl is 0 which is a half wavelength of the 1 kHz acoustic signal It will be .17m.
[0047]
The BPF 514 outputs, to the supply unit 524 of the fourth band speaker set 4A4, an acoustic
signal of a frequency band centered at 1.4 kHz, which is a half octave higher than the center
frequency 1 kHz of the BPF 513. The supply unit 524 transmits the acoustic signals band-divided
09-05-2019
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by the BPF 514 to the first speaker unit 4B4fr, the second speaker unit 4B4fl, the third speaker
unit 4B4rr, and the fourth speaker unit 4B4rl in a phase as described later. Supply. In addition,
the distance d4 between the front and rear and the left and right of the first speaker unit 4B4fr,
the second speaker unit 4B4fl, the third speaker unit 4B4rr, and the fourth speaker unit 4B4rl is
1/2 of the acoustic signal with a center frequency of 1.4 kHz. The wavelength is 0.12 m.
[0048]
The BPF 515 outputs an acoustic signal of a frequency band centered on 2 kHz, which is 1⁄2
octave higher than the center frequency of 1.4 kHz of the BPF 514, to the supply unit 525 of the
fifth band speaker set 4B5. The supply unit 525 transmits the acoustic signals band-divided by
the BPF 515 to the first speaker unit 4B5fr, the second speaker unit 4B5fl, the third speaker unit
4B5rr, and the fourth speaker unit 4B5rl in a phase as described later. Supply. In addition, an
interval d5 between front and rear and left and right of the first speaker unit 4B5fr, the second
speaker unit 4B5fl, the third speaker unit 4B5rr, and the fourth speaker unit 4B5rl is a half
wavelength of an acoustic signal having a center frequency of 2 kHz. It will be 0.085 m.
[0049]
The BPF 516 outputs, to the supply unit 526 of the sixth band speaker set 4B6, an acoustic
signal of a frequency band centered on a frequency 2.82 kHz, which is a half octave higher than
the center frequency 2 kHz of the BPF 515. The supply unit 526 sends the acoustic signals banddivided by the BPF 516 to the first speaker unit 4B6fr, the second speaker unit 4B6fl, the third
speaker unit 4B6rr, and the fourth speaker unit 4B6rl in a phase as described later. Supply. In
addition, an interval d6 between the front and rear and left and right of the first speaker unit
4B6fr, the second speaker unit 4B6fl, the third speaker unit 4B6rr, and the fourth speaker unit
4B6rl is 1/2 of an acoustic signal with a center frequency of 2.82 kHz. The wavelength is 0.06 m.
<Operation> The supply unit 52n supplies the acoustic signal sent from the BPF 51n to the first
speaker unit 4Bnfr and the second speaker unit 4Bnfl in the same phase, to the third speaker unit
4Bnrr and the fourth speaker unit 4Bnrl. When a sound signal obtained by inverting the phase of
the sound signal supplied to the first speaker unit 4Bnfr is supplied, the speaker device 4 has
high directivity in the front-rear direction as in FIG.
[0050]
The supply unit 52n supplies the acoustic signal sent from the BPF 51n to the first speaker unit
4Bnfr and the third speaker unit 4Bnrr in the same phase, and the first speaker unit 4Bfrl and the
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fourth speaker unit 4Bnrl receive the first sound signal. When an acoustic signal obtained by
inverting the phase of the acoustic signal supplied to the speaker unit 4Bnfr is supplied, the
speaker device 4 has high directivity in the left-right direction as in FIG. 6 b).
[0051]
The supply unit 52n supplies the acoustic signal sent from the BPF 51n to the first speaker unit
4Bnfr and the fourth speaker unit 4Bnrl in the same phase, and the first speaker to the second
speaker unit 4Bnfl and the third speaker unit 4Bnrr. When an acoustic signal obtained by
inverting the phase of the acoustic signal supplied to the unit 4Bnfr is supplied, the speaker
device 4 has an X-shaped directional characteristic in which the sound pressure in the oblique
direction is high as in FIG.
[0052]
As described above, the speaker device according to the present embodiment can easily change
the directivity by selectively inverting and supplying the phase of the acoustic signal supplied to
each speaker unit.
[0053]
Even if the distance dn between the speaker units is not exactly λn / 2, as in the first
embodiment, the effects can be obtained as long as 0.3λn ≦ dn <0.7λn.
More preferably, if 0.45 λ n d d <0.65 λ n, a larger effect is obtained.
Furthermore, even if the distance between the front and back of the speaker units and the
distance between the left and right are not necessarily the same, an effect can be obtained as
long as each is within the range described above.
In addition, even if the speaker set as described above does not output the sound signals of all
the divided frequency bands, the sound signal of the frequency band for which high directivity is
desired is output as the speaker set as described above. Play.
[0054]
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In the n speaker sets 4Bn of the speaker device 4, the speaker units driven by the opposite phase
acoustic signals constitute the same dipole speaker as in the first embodiment. That is, the
respective speaker sets have high directivity because they cancel each other's acoustic signals in
the left and right direction and enhance the acoustic signals in the front and back direction.
[0055]
Further, in the n speaker sets 4Bn of the speaker device 4, the speaker units driven by the inphase acoustic signals constitute the same tone zone speaker as in the first embodiment. Since
the tone snail type speaker device has high directivity in the front-rear direction with respect to a
signal having a wavelength approximately twice that of the left and right unit interval, directivity
can be further improved.
[0056]
By changing the phase of the audio signal supplied to each speaker unit, it is possible to instantly
switch between the speaker unit constituting the dipole system and the speaker unit constituting
the tone zone system, so that the directivity can be easily changed. Can.
[0057]
In addition, n sets of speaker sets 4Bn of the speaker device 4 use the four speaker units to
exhibit high directivity, and in the lateral direction, it is only necessary to arrange the two
speaker units with a half wavelength width. Therefore, the size can be reduced as compared with
the conventional speaker device.
[0058]
Also, since each speaker set has a narrow frequency band, it has a sufficiently high directivity.
Furthermore, since n speaker sets in which the distance between the front and rear and the left
and right are changed are used for each appropriate frequency band, the speaker device as a
whole becomes a speaker device having high directivity over a wide frequency band.
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Therefore, even when it is desired to output a sound source in a wider frequency band such as
BGM (Back Ground Music), sufficient directivity can be obtained.
[0059]
The speaker device according to this embodiment not only has high directivity over a wide
frequency band, but also selectively reverses the phase of the acoustic signal supplied to each
speaker unit to make the direction with high directivity It can be in the direction, in the left or
right direction, or in the oblique direction.
[0060]
Thus, the speaker device of the present embodiment can easily change directivity by switching
the phase of the acoustic signal supplied to each speaker unit.
[0061]
1, 4 speaker device 20, 50 input unit 51, 51n band division unit 21, 52n supply unit 4Bn
Speaker set 101, 4Bnfr first speaker unit 102, 4Bnfl second speaker unit 103, 4Bnrr third
speaker unit 104, 4Bnrl fourth Speaker unit
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