JP2017046309

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DESCRIPTION JP2017046309
Abstract: The present invention provides an acoustic device capable of securing a sufficient
sound pressure / reproduction band even when using a small and lightweight speaker unit, and
capable of localizing a sound image at an intended position. A sound device comprising three or
more main speaker units (SF1, SF2, SF3...) Aligned outside the display screen 60 and reproducing
input signals of a plurality of channels, comprising two or more sub-speaker units (SL1, SL2...),
Each sub-speaker unit is disposed in a gap between two adjacent main speaker units, and in each
sub-speaker unit, a main speaker signal corresponding to each two adjacent main speaker units A
signal obtained from frequency components below the threshold of is reproduced. [Selected
figure] Figure 2
Acoustic device
[0001]
The present invention relates to an acoustic device, and more particularly to an acoustic device
having a multi-channel acoustic reproduction function.
[0002]
BACKGROUND ART In recent years, an audio device has been generalized in which sound is
recorded with multiple channels and reproduced from a speaker disposed so as to surround the
periphery of a viewer to obtain a high sense of reality.
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Services for distributing 5.1 ch and 7.1 ch audio via recording media such as broadcasting and
optical disks, networks, etc. are provided. These surround the viewer with five or seven speakers
and perform sound reproduction from behind. Furthermore, a three-dimensional multi-channel
acoustic system has also been proposed, in which speakers are provided above and below and
sound is reproduced also from above and below.
[0003]
As shown in FIGS. 10 (a) to (d) and FIG. 11, the three-dimensional multi-channel acoustic system
(hereinafter abbreviated as 22.2 ch) has 9 top layers, 10 middle layers, 3 bottom layers, and a
bass It is a system consisting of two sound channels, and is defined in ARIB STD-B 59 standard
(hereinafter ARIB standard) of Non-Patent Document 1. In 22.2 ch, a total of 11 sound channels,
3 top, 5 middle and 3 bottom layers shown in Fig. 10 and Fig. 11, are reproduced in front of the
viewer, especially in front of the viewer. When displayed, an expression in which the image and
the sound image coincide with each other can be made, and the sense of immersion can be
enhanced.
[0004]
However, when displaying an image in front, the positional relationship between the three
acoustic channels FLc, FC, FRc included in the middle layer and the display device becomes a
problem. When an image is displayed on a sound transmission type screen and a speaker unit for
reproducing these three sound channels FLc, FC, FRc is installed on the back of the screen, sound
image presentation meeting ARIB standards is possible, for example Since a general liquid crystal
display is not of the sound transmission type, a speaker can not be arranged on the back surface,
and a speaker for reproducing the three sound channels FLc, FC, FRc can not be arranged at an
appropriate position.
[0005]
In order to solve this, as shown in FIG. 12, 12 speaker units are arranged so as to surround the
liquid crystal display LCD, and three sound channels FLc, FC, FRc included in the middle layer are
placed above the screen and There has been proposed a technology in which sound reproduction
is perceived as being performed from the top of the screen by reproduction from both of the
speaker units provided below (see Patent Document 1 and Non-patent Document 2).
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[0006]
JP 2008-109209 (May 8, 2008 publication)
[0007]
ARIB STD-B59 3D multi-channel audio system studio standard 12-Loudspeaker System for ThreeDimensional Sound Integrated with Flat-Panel Display Satoshi Oode, Kentaro Matsui, Satoshi
Ooishi, Takehiro Sugimoto, and Yasushige Nakayama, Japan Broadcasting Corporation (NHK) ...
NAB Broadcast Engineering Conference Proceedings 2014 ... 184-189
[0008]
According to the method of FIG. 12, the sound image of the middle layer arranged forward can
also be reproduced using 12 speaker units, and if the height constraints of the listener are
satisfied, 11 sound source positions with respect to the front Everything can be reproduced.
Furthermore, if the virtual surround method is used in combination, sound reproduction of 22.2
channels becomes possible in a specific listening area.
[0009]
However, when the 12 speaker units are mounted around the television, the installation of the
speaker units is restricted due to the weight, the design, and the like.
Due to limitations in weight and design, small-diameter, lightweight speaker units must be
selected, but small-diameter speaker units are generally inferior in sound pressure that can be
generated to large-diameter ones and tend to be inferior in bass reproduction ability The sound
pressure and the reproduction band are both insufficient.
[0010]
Furthermore, when using the above-mentioned virtual surround method in combination, less
distortion is required at the time of reproduction, but if the speaker unit is operated with large
amplitude, distortion increases, so it is necessary to reduce the reproduction sound pressure. It
can not be reproduced with a sound pressure that is sufficiently sufficient.
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[0011]
Even if the speaker unit with a small aperture is limited to the low frequency reproduction band,
it is possible to secure the bass reproduction capability. Therefore, these 12 speaker units have a
multi-way system such as a 2-way configuration, and dedicated speaker units for each band By
providing this, the reproduction band can be expanded even if a small aperture speaker unit is
used.
However, the number of speaker units to be used increases, and a problem arises that the sound
image is dispersed for each of the speaker units constituting the multiway.
[0012]
The present invention has been made in view of the above problems, and an object thereof is to
provide an acoustic device capable of securing a necessary sound pressure and a reproduction
band even if a small and lightweight speaker unit is used.
[0013]
An audio apparatus comprising three or more main speaker units arranged outside the display
screen and reproducing input signals of a plurality of channels, comprising two or more sub
speaker units, each sub speaker unit comprising two adjacent main speakers The sub-speaker
units are disposed in the gaps between the units, and each sub-speaker unit is characterized in
that a signal obtained from a frequency component less than a threshold value of an output
signal corresponding to each of two adjacent main speaker units is reproduced.
[0014]
In the audio apparatus according to one aspect of the present invention, a sub speaker unit that
reproduces a signal obtained from a frequency component less than a threshold value of an
output signal corresponding to each of two main speaker units in a gap between two adjacent
main speaker units. As a result, even if a small and light speaker unit is used as the main speaker
unit, the necessary sound pressure and reproduction band can be secured, and the sound image
can be localized at the intended position.
[0015]
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FIG. 1 is a block diagram showing a configuration of an acoustic device of Embodiment 1.
FIG. 2 is a front view showing a configuration of a speaker unit of Embodiment 1;
It is a table | surface which shows the relationship between the output channel of the acoustic
apparatus of Embodiment 1, and an acoustic channel of 22.2 ch.
(A) and (b) are tables showing the filter system of each output channel.
FIG. 6 is a block diagram showing the configuration of an acoustic device of a second
embodiment. FIG. 10 is a front view showing the configuration of the speaker unit of
Embodiment 2; FIG. 16 is a front view showing another configuration of the speaker unit of
Embodiment 2. FIG. 7 is a schematic view showing a filter configuration of Embodiment 2. It is a
table | surface which shows the relationship between the output channel of the audio equipment
of Embodiment 2, and an acoustic channel of 22.2ch. (A)-(d) is a schematic diagram which shows
arrangement | positioning of a 22.2 ch sound source (sound channel). It is a table showing sound
channel names of 22.2 ch and their labels. It is a schematic diagram which shows the
reproduction | regeneration method of 22.2ch disclosed by the nonpatent literature 2. FIG.
[0016]
It will be as follows if embodiment of this invention is described based on FIGS. 1-12.
[0017]
Hereinafter, embodiments of the present invention will be described in detail.
However, the configuration described in this embodiment is not intended to limit the scope of the
present invention to that alone, unless specifically described, and is merely an illustrative
example. In the following description, "voice" is a general voice handled by an acoustic product,
and includes human voice, background sound, and musical tones.
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[0018]
Embodiment 1 (Configuration of Sound Device) FIGS. 1A and 1B are block diagrams showing the
configuration of a sound device according to Embodiment 1. FIG. As shown in FIG. 1A, the
acoustic device 20 controls the input unit 21, the signal processing unit 22, the amplification
unit 23, the speaker unit 25, the input unit 21, the signal processing unit 22, and the
amplification unit 23. The control unit 28 performs an audio output by reproducing an output
signal obtained by performing signal processing or the like on an input signal from the external
device 70. As shown in FIG. 1B, the signal processing unit 22 includes a volume adjustment unit
31, a virtual surround processing unit 32, a mixing unit 33, and a filter unit 34.
[0019]
As shown in FIG. 2, the speaker unit 25 includes 12 full-range speaker units (main speaker units)
SF1 to SF12 and 12 bass speaker units (sub-speaker units) SL1 to SL surrounding the periphery
of the rectangular display screen 60. It has SL12. Note that the full-range speaker unit is
configured to be able to reproduce low to high tones with one speaker unit, and the low-pitch
speaker unit is configured to be able to suitably reproduce low tones, for example, The aperture
of the bass speaker unit is designed to be larger than the aperture of the full range speaker unit,
or the diaphragm weight of the bass speaker unit is designed to be larger than the diaphragm
weight of the full range speaker unit, resulting in the lowest resonance of the speaker unit. It is
assumed that the frequency (F0) is designed to be low. Also, the bass speaker unit does not
necessarily have to have the diaphragm installed in the forward direction. For example, the
diaphragm may be installed in the back direction, and a duct or the like may be installed in the
forward direction. In this case, even if one having a larger diameter as the bass speaker unit is
used, the forward apparent area of the speaker portion can be reduced.
[0020]
In FIG. 2, speaker units SF1, SF8, SF12, and SF5 are disposed clockwise around the four corners
of the display screen 60. In addition, speaker units SF2, SF3 and SF4 are arranged in order from
the speaker unit SF1 side in a region which is the gap between the speaker units SF1 and SF5
and is on the outside of one of the two long sides of the display screen 60. Speaker units SF9,
SF10, and SF11 are arranged in order from the side of the speaker unit SF8 in a region that is the
gap between SF8 and SF12 and is on the other side of the other of the two long sides of the
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display screen 60. A speaker unit SF6 is disposed in an area which is a gap between SF8 and one
of the two short sides of the display screen 60 and is a gap between the speaker units SF5 and
SF8, and the other outside of the two short sides of the display screen 60. The speaker unit SF7 is
disposed in the area where Furthermore, one bass speaker unit is disposed between two adjacent
full-range speaker units.
[0021]
As described above, around the display screen 60, the speaker units SF1 (corner), SL1, SF2, SL2,
SF3, SL3, SF4, SL5, SF5 (corner), SL6, SF7, SL8, SF12 (corner) turn clockwise. , SL12, SF11, SL11,
SF10, SL10, SF9, SL9, SF8 (corner), SL7, SF6, SL5. Note that although it is preferable that the
bass speaker unit is disposed in the middle between adjacent full-range speaker units, two bass
speaker units may be disposed at positions equidistant from the full-range speaker unit. It is not
necessary to arrange in the middle of adjacent full range speaker units.
[0022]
Returning to FIG. 1, the input unit 21 receives an input signal from the external device 70 by
wire or wirelessly, and outputs the input signal to the signal processing unit 22. The input signal
is a digital signal of 24 channels (see FIGS. 10 and 11) of a three-dimensional multi-channel
acoustic system (hereinafter abbreviated as 22.2 ch) format defined in ARIB STD-B 59 standard
of Non-Patent Document 1 , In the upper layer (top layer) of the listener's head (top layer), 9
channels corresponding to 9 sound sources equidistant from the head, and in the same layer
(middle layer) of the listener's head 10 channels corresponding to 10 sound sources equidistant
to 2nd, 3 channels lower than the head of the listener (bottom layer), 3 channels corresponding
to 3 sound sources equidistant from the head, 2 corresponding to the bass effect It consists of a
channel.
[0023]
The nine channels on the top layer of 22.2 ch are the three channels of TpFL, TpFC, and TpFR
corresponding to the sound sources in the upper left, upper front, upper right, upper front and
upper left of the listener, and the upper left of the listener Two channels of TpSiL and TpSiR
corresponding to the respective sound sources in the upper right, and three channels of TpBL,
TpBC, and TpBR corresponding to the respective sound sources in the upper left rear, upper rear,
and upper right rear of the listener And one channel of TpC corresponding to the sound source
immediately above.
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[0024]
The 10 channels applied to the 22.2 middle layer are FL, FLc, FC, and FRc corresponding to the
sound sources of the listener's left front left, front left front, front, front right, front right, and
front right diagonal, respectively. , FR 5 channels, SiL and SiR 2 channels corresponding to the
sound sources on the left and right sides of the listener, and BL corresponding to sound sources
on the left rear, back and right rear of the listener, It consists of 3 channels of BC and BR.
[0025]
Three channels applied to the bottom layer of 22.2 channels are configured by BtFL, BtFC, and
BtFR corresponding to the sound sources of the listener's left lower front, lower front, and lower
right front, respectively.
[0026]
The two channels corresponding to the bass effect are configured by LFE-1 and LFE-2 that do not
specify the sound source position.
[0027]
Although an input signal of 22.2 ch format can be transmitted by one by the HDMI (registered
trademark) cable and by 24 by the analog pin connector cable, the form of signal transmission is
not particularly limited.
When an HDMI cable is used, the video signal and the audio signal are superimposed, but in the
audio device 20, only the audio signal is extracted and used, and the video signal is separately
connected to the display device.
It may be configured to receive only the audio signal from the display device via the HDMI.
[0028]
The signal processing unit 22 processes the input signal (digital signal of 22.2 ch format)
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received by the input unit 21 and outputs the processed signal to the amplification unit 23.
Specifically, the volume adjuster 31 adjusts the level of the input signal, and the 11 channels
corresponding to the forward sound source (TpFL, TpFC, TpFR, FL, FLc, FC, FRc, FR, BtFL, BtFC
shown in FIG. 10) , BtFR) Two-channel (LFE-1, LFE-2) bass signals (low-frequency signals below a
predetermined frequency) corresponding to the bass effect and 11 channels (non-forward sound
source) corresponding to the ambient sound source (non-forward sound source) It is separated
into the ambient signals of BL, BR, BC, SiL, SiR, TpC, TpBL, TpBR, TpSiL, TpSiR, TpBC), and 11
forward signals are output to the mixing section 33, and 11 ambient signals are virtual. It is
output to the surround processing unit 32.
[0029]
The virtual surround processing unit 32 performs virtual surround processing to cause ambient
signals of 11 channels to be perceived as being emitted from a non-existent speaker unit with
respect to a specific listening position, and outputs the processed signal to the mixing unit 33.
[0030]
The mixing unit 33 mixes the front signals of 11 channels and the bass signals of 2 channels
according to the speaker unit arrangement of the speaker unit 25 (see FIG. 2), and further the
ambient signals of 11 channels subjected to virtual surround processing are By adding, the
output signals of 24 channels (F1 to F12 and L1 to L12) corresponding to the speaker unit array
(full range speaker units SF1 to SF12 and bass speaker units SL1 to SL12 in FIG. 2) are used as
filter units 34. Output to
[0031]
The filter unit 34 subjects the output signal to filter processing in accordance with the
corresponding speaker unit, and outputs the result to the amplification unit 23.
Specifically, band limitation is performed so that each speaker unit passes only the assumed
frequency band.
Further, processing may be performed to correct the reproduction frequency characteristic of
each speaker unit so as to adjust the overall frequency characteristic.
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[0032]
The amplification unit 23 amplifies the output signal subjected to the filtering process by the
filter unit 34 into a drive signal of the speaker unit, and outputs the drive signal to the speaker
unit 25.
[0033]
In the speaker unit 25, the 24 speaker units (full range speaker units SF1 to SF12 and bass
speaker units SL1 to SL12) of FIG. 2 are driven by the drive signal from the amplification unit 23,
and sound output (reproduction) is performed.
[0034]
The control unit 29 receives a listener's input to the remote controller 80 as a signal from the
remote controller 80, and outputs a control signal to at least one of the input unit 21, the signal
processing unit 22, and the amplification unit 23.
The instruction of the listener includes power on / off, input switching, volume adjustment,
sound quality switching, virtual surround processing on / off, and the like.
[0035]
(Operation of Sound Device) The operation of the sound device will be described below.
[0036]
When the listener inputs power ON to the remote controller 80, the control unit 28 receives a
signal from the remote controller 80 and performs processing for activating the acoustic device
20.
The start-up process is a process of energizing each part to release muting of the amplification
unit 23 when it is in an operable state, and to actually make it possible to emit sound.
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[0037]
When the start-up process is completed, the input unit 21 receives an input signal from the
connected external device 70.
The input unit 21 can receive a plurality of input signals, but receives an input signal (selected by
a listener) according to a signal from the control unit 28.
[0038]
The input unit 21 can cope with various signal formats, but the input signal accepted here is an
audio signal of 22.2 ch format using HDMI 2.0.
[0039]
The input unit 21 converts the audio signal into a unified digital signal and outputs the digital
signal to the signal processing unit 22.
Here, the unified digital signal defines, for example, a sampling frequency of 48 kHz, and
includes processing for converting the sampling frequency to 48 kHz when receiving other input
signals.
Also when the analog signal is received, it is converted to the same format by AD conversion.
[0040]
In the signal processing unit 22, first, the volume adjustment unit 31 performs volume
adjustment of the input signal. The volume processing unit 31 multiplies the input signal by a
coefficient corresponding to the set volume set by the control unit 28 to reflect the set volume of
the listener. As described above, the input signal level-adjusted by the volume adjustment unit 31
is located around the 11-channel forward signal corresponding to the 11 sound sources located
forward and the 2-channel bass signal corresponding to the bass effect The signal is separated
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into the ambient signals of 11 channels corresponding to the 11 sound sources, the forward
signals of 11 channels are output to the mixing section 33, and the ambient signals of 11
channels are output to the virtual surround processing section 32.
[0041]
The virtual surround processing unit 32 performs localization processing and crosstalk filter
processing on ambient signals.
[0042]
In localization processing, the HRTFs corresponding to the sound source positions viewed from
the listener position are convoluted with the signals corresponding to the positions of the
surrounding 11 sound sources viewed from the listener position, and the left and right ears
Combine signals on the two channels corresponding to the inputs to the road.
[0043]
The HRTF is a characteristic of a space from a certain position to being input to the listener's ear
canal, and reflects a signal affected by the shape of a human head, shoulder, pinna and the like.
The HRTF convolution can give the same characteristics as passing through a space from a
certain position to being input to the ear canal, so by reproducing in the listener's ear canal, the
listener can start from a certain position Perception as if it were a sound that was emitted.
[0044]
Here, the sound emitted from a certain position passes through the space and enters the
listener's ears, but the sound emitted from a position different from the certain position is
different from the sound emitted from the certain position In order to enter both ears of the
listener, by combining the sounds emitted from these two positions, it is possible to respectively
generate sounds that approximately enter only one ear of the listener.
These processes are referred to herein as crosstalk filtering.
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[0045]
Therefore, crosstalk filter processing is performed on signals of two channels corresponding to
inputs to the left and right ear canals in accordance with the number of speaker units actually
used for virtual surround reproduction. As a result, the same effect as reproducing HRTFprocessed sound at the ear of the listener located at a specific position is obtained, and it may be
as if the speaker units are present at the corresponding positions as if the 11 sound sources
around each other. It can be made to be able to be perceived by the listener like.
[0046]
The mixing unit 33 mixes the front signals of 11 channels and the bass signals of 2 channels
according to the speaker unit arrangement of the speaker unit 25 (see FIG. 2), and further the
ambient signals of 11 channels subjected to virtual surround processing are By adding, the
output signals of 24 channels (F1 to F12 and L1 to L12) corresponding to the speaker unit array
(full range speaker units SF1 to SF12 and bass speaker units SL1 to SL12 in FIG. 2) are used as
filter units 34. Output to
[0047]
The output signal (digital signal) of the 24 channels is subjected to filter processing by the filter
unit 34, further amplified by the amplification unit 23 into a drive signal of the speaker unit, and
input to the speaker unit 25.
Since it is necessary to input an analog signal to the speaker unit 25, the amplification unit 23
performs amplification after DA conversion. The received digital signal may be internally
processed to generate an analog signal amplified by the switching operation.
[0048]
The speaker unit 25 will be described below.
[0049]
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In the speaker unit 25, as shown in FIG. 2, the full range speaker units SF <b> 1 to SF <b> 12 are
arranged around the display screen 60.
That is, for the front 11 channels in FIG. 10, eight channels (TpFL, TpFC, TpFR, FL, FR, BtFL, BtFC,
BtFR) correspond to the actual speaker units (SF1, SF3, SF5, respectively) at corresponding
positions. For three channels (FLc, FC, FRc) reproduced from SF6, SF7, SF8, SF10, SF12 and to
which no actual speaker unit is associated, the actual speaker units (for example, FLc) located at
the upper and lower positions respectively Is played from the speaker units SF2 and SF9) with
the same sound pressure, so that when listening from the upper and lower real speaker units
equidistantly, it makes the sound appear to be from the middle point of the straight line
connecting the upper and lower speaker units. Can also correspond to FLc, Fc, and FRc on the
screen. The sound is felt as out of the.
[0050]
Although the full-range speaker unit is designed to reproduce the entire audible band with a
single speaker unit, in reality the high and low frequencies are in a trade-off relationship, and in
general the high frequency characteristics The low frequency characteristics tend to be inferior
when the B. is enhanced, and the high frequency characteristics tend to be inferior when the low
frequency characteristics are enhanced. In general, increasing the aperture of the speaker unit is
advantageous for bass reproduction, but it is disadvantageous for high-pitched sound
reproduction, and decreasing the aperture tends to be reversed. Since the larger diameter is more
advantageous for moving a large amount of air, the larger diameter tends to generate higher
sound pressure.
[0051]
When considering a product as a television and its peripherals, it is common to choose a smallaperture speaker unit due to design and weight constraints. Also in each of the speaker units
(upper L and the like) of FIG. 12, a speaker unit with a small diameter can not but be used
because of the restriction of the width allowed as a product, and if this is a full range speaker
unit, low frequency characteristics become disadvantageous. In addition, if an attempt is made to
generate a high sound pressure, the diaphragm will be largely displaced, leading to the
generation of distortion. In particular, when it is intended to generate low sound pressure with a
high sound pressure, the displacement of the diaphragm becomes large, exceeding the
displacement width allowed for the diaphragm, causing large distortion, or damaging the speaker
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unit.
[0052]
Therefore, in the acoustic device 20, the drive signal applied to the full-range speaker unit is
filtered so that displacement of the diaphragm does not increase even if the full-range speaker
unit is used, and after a predetermined frequency or less is attenuated Arrange the unit to assist
in the bass reproduction. For this reason, in the speaker unit 25, a bass speaker unit is disposed
in the middle between two adjacent full-range speaker units.
[0053]
The drive signals applied to the full-range speaker units SF1 to SF12 are filtered to attenuate
signals below a threshold (for example, a value of 100 Hz to 400 Hz). In this way, the
displacement of the diaphragm of full range speaker units SF1 to SF12 can be reduced to
suppress distortion, and further, with regard to the sound generated from the full range speaker
unit, its sound image can be localized to the full range speaker unit .
[0054]
The signal below the threshold (for example, a value of 100 Hz to 400 Hz) attenuated from the
drive signal of the full range speaker unit assists the sound pressure by reproducing from the
bass speaker unit. Specifically, with respect to two bass speaker units adjacent to the full range
speaker unit, the signal allocated to the full range speaker unit is subjected to a filter for
attenuating a signal of a threshold (for example, a value of 100 Hz to 400 Hz) Apply. By doing
this, it is possible to compensate for the bass attenuated by the drive signal of the full range
speaker unit. In addition, when the two bass speaker units adjacent to the full-range speaker unit
are arranged in a straight line equidistantly on both sides of the full-range speaker unit, the
sound reproduced with the same sound pressure from the two bass speaker units is Since
localization is performed on the full range speaker unit, as a result, good sound reproduction in
which a sound image is localized on the full range speaker unit in a wide band is possible.
[0055]
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These processes are applied to all full range speaker units SF1 to SF12. At this time, although
there are no bass speaker units arranged on a straight line for the full range speaker units (SF1,
SF5, SF8, SF12) at the four corners, since there is a bass speaker unit in the vicinity of each full
range speaker unit, There is no significant localization degradation related to the full range
speaker units at the four corners.
[0056]
By keeping the arrangement of the bass speaker units equidistant from the respective full range
speaker units, the problem of sound image localization can be improved by bringing the
arrangement close to the full range speaker units at the four corners.
[0057]
Here, although the attenuation frequencies of the full range speaker unit and the bass speaker
unit are approximately 100 Hz to 400 Hz, these do not necessarily have to match.
Specifically, a high-pass filter of 150 Hz may be applied to the drive signal of the speaker unit
SF3, and a low-pass filter of 200 Hz may be added to the drive signal of the speaker unit SF3 to
the speaker units SL2 and SL3. In this way, the speaker units SF3, SL2 and SL3 overlapping in
the reproduction frequency band are simultaneously reproduced, and the reproduction
performance in the low band can be improved. The order of these filters need not be high, and
may be about 6 db / oct. The signals from the respective adjacent full-range speaker units are
added to and reproduced by the respective bass speaker units.
[0058]
A common 2 Way speaker unit divides the reproduction band into two speaker units and
reproduces the same, but adds a high sound speaker unit that reproduces only high sound to a
low sound speaker unit advantageous for low sound reproduction, Is often about 1 kHz to 8 kHz.
When such a multi-way speaker unit is used, the sound image moves to the speaker unit
corresponding to each band.
[0059]
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In the first embodiment, according to the speaker unit arrangement (SF1 to SF12, SL1 to SL12)
of the speaker unit 25 and the drive specifications shown in FIG. decide. An example of the
coefficients of the mixing unit 33 is shown in FIG. 3, and an example of setting of the filter unit
34 is shown in FIG.
[0060]
The channels (output channels) of output signals for the full range speaker units SF1 to SF12 in
FIG. 2 are F1 to F12, and the channels (output channels) of output signals for the bass speaker
units SL1 to SL12 in FIG. 2 are L1 to L12. The input signal is assumed to be 24 acoustic channels
shown in FIGS.
[0061]
As shown in FIG. 3, the output channel F1 uses the acoustic channel TpFL, the output channel F2
uses the acoustic channel FLc, the output channel F3 uses the acoustic channels FC and TpFC,
and the output channel F4 uses the acoustic channel FRc. The channel F5 uses the acoustic
channel TpFR, the output channel F6 uses the acoustic channel FL, the output channel F7 uses
the acoustic channel FR, the output channel F8 uses the acoustic channel BtFL, and the output
channel F9 uses the acoustic channel FLc and outputs The channel F10 uses the acoustic
channels FC and BtFC, the output channel F11 uses the acoustic channel FRc, and the output
channel F12 uses the acoustic channel BtFR.
[0062]
Also, in the output channel L1, the acoustic channels LFE-1, FLc, and TpFL are used, in the output
channel L2, the acoustic channels FC, LFE-1, FLc, and TpFC are used, and in the output channel
L3, the acoustic channels FC, FRc, LFE-2 And TpFC, the output channel L4 uses the acoustic
channels FRc, LFE-2 and TpFR, the output channel L4 uses the acoustic channels FRc, LFE-2 and
TpFR, and the output channel L5 the acoustic channel FL, LFE-1 And TpFL, the output channel L6
uses the acoustic channels FR, LFE-2 and TpFR, the output channel L7 uses the acoustic channels
FL, LFE-1 and BtFL, and the output channel L8 uses the acoustic channel Using FR, LFE-2 and
BtFR, the output channel L9 uses the acoustic channels LFE-1, FLc and BtFL, and the output
channel L10 uses the acoustic channels FC, LFE-1, FLc and BtFC, the output channel L11 In the
above, the acoustic channels FC, FRc, LFE-2 and BtFC are used, and in the output channel L12,
the acoustic channels FRc, LFE-2 and BtFR are used.
[0063]
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17
Here, as shown in FIGS. 4A and 4B, the output channels F1 to F12 are subjected to an HPF (high
pass filter) having a cutoff frequency of 150 Hz and a filter characteristic of 12 db / oct, and the
output channels L1 to L12. , Cutoff frequency 120 Hz (threshold), filter characteristic 6 db / oct
LPF (low pass filter) is applied.
[0064]
In this way, it is possible to realize an acoustic device capable of generating a sound pressure
higher than that in the case where the speaker unit is configured using only the full range
speaker unit while maintaining the sound image localization performance, in a good frequency
band.
Further, when the same sound pressure as that of the full range speaker unit is generated, the
distortion can be suppressed to a low level. Therefore, when the virtual surround technology or
the like is used together, the effect can be realized better.
When the signal subjected to virtual surround processing is supplied only to the full range
speaker unit, the above-described effect of suppressing distortion can be favorably exhibited.
However, when the signal is also supplied to the bass speaker unit, the behavior of the bass
speaker unit changes.
However, it is difficult to position the bass as intended by the virtual surround technology, so
there is no significant impact.
[0065]
If the speaker unit of the speaker unit 25 corresponds to the amplifier of the amplifier unit 23
one by one, an amplifier optimized for the speaker unit can be used.
In general, a bass speaker unit is required to have a large input resistance and a large driving
power, so a strong amplifier should be provided for the bass speaker unit and a standard
amplifier should be provided for the full range speaker unit. Can reduce costs.
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[0066]
Further, in FIG. 3, two channels (LFE-1, LFE-2) corresponding to the bass signal are added to the
output channels, and the sound images of LFE-1 and LFE-2 are defined in accordance with the
actual speaker unit arrangement. Therefore, among the bass signals, it is possible to satisfactorily
reproduce a signal of a band having a relatively high frequency and affecting the localization. As
a result, since the coincidence between the image and the sound image can be measured
including the LFE-1 and LFE-2 bass signals, it is possible to present a more immersive image /
sound.
[0067]
Second Embodiment FIGS. 5A and 5B are block diagrams showing the configuration of an
acoustic device according to a second embodiment. As shown in FIG. 5A, the acoustic device 40
includes an input unit 41, a signal processing unit 42, an amplification unit 43, a filter unit 44, a
speaker unit 45, an input unit 41, a signal processing unit 42, The control unit 48 controls the
amplification unit 43, and performs audio processing by reproducing an output signal obtained
by performing signal processing or the like on an input signal from the external device 70. As
shown in FIG. 5B, the signal processing unit 42 includes a volume adjustment unit 51, a virtual
surround processing unit 52, and a mixing unit 53.
[0068]
As shown in FIG. 6, the speaker unit 45 includes ten full range speaker units SF101 to SF110 and
eight bass speaker units SL101 to SL108 disposed above and below the rectangular display
screen 60. Specifically, speaker units SF101, SF105, SF110, and SF106 are disposed clockwise
around the four corners of the display screen 60. In addition, speaker units SF102, SF103, and
SF4 are arranged in order from the speaker unit SF101 side in a region that is the gap between
the speaker units SF101 and SF105 and is on the outside of one of the two long sides of the
display screen 60. Speaker units SF107, SF108, and SF109 are arranged in order from the side of
the speaker unit SF106 in a region which is the gap between the SF 106 and the SF 110 and is
on the other side of the other two long sides of the display screen 60. One bass speaker unit is
disposed between the full range speaker units.
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[0069]
As described above, the speaker units SF101 (corners), SL101, SF102, SL102, SF103, SL103,
SF104, SL104, S10F5 (corners) are arranged in order from the left on the upper side of the
display screen 60 and the lower side of the display screen 60 In the figure, SF 106 (corner), SL
105, SF 107, SL 106, SF 108, SL 107, SF 109, SL 108, SF 110 (corner) are arranged in order
from the left.
[0070]
Referring back to FIG. 5, the input unit 41 receives an input signal from the external device 70 by
wire or wirelessly, and outputs the input signal to the signal processing unit 42.
The input signal is a digital signal of 22.2 ch format (24 channels) shown in FIG. 10 and FIG.
[0071]
The signal processing unit 42 processes the input signal (digital signal of 22.2 ch format)
received by the input unit 41, and outputs the processed signal to the amplification unit 43.
Specifically, the volume adjuster 51 adjusts the level of the input signal, and the 11 channels
corresponding to the sound source located in front (TpFL, TpFC, TpFR, FL, FLc, FC, FRc, FR,
shown in FIG. 10). BtFL, BtFC, BtFR) Two-channel (LFE-1, LFE-2) bass signals corresponding to
the front effect and bass effect, and 11 channels (BL, BR, BC, SiL, The signal is separated into the
ambient signals of SiR, TpC, TpBL, TpBR, TpSiL, TpSiR, TpBC), the forward signals of 11 channels
are output to the mixing section 53, and the ambient signals of 11 channels are output to the
virtual surround processing section 52.
[0072]
The virtual surround processing unit 52 performs virtual surround processing to cause ambient
signals of 11 channels to be perceived as being emitted from a non-existent speaker unit with
respect to a specific listening position, and outputs the processed signal to the mixing unit 53.
[0073]
The mixing unit 53 mixes the front signals of 11 channels and the bass signals of 2 channels
according to the speaker unit arrangement (described later), and adds the ambient signals of 11
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channels subjected to virtual surround processing to the speaker Output signals of 10 channels
(F101 to F110) corresponding to the unit arrangement (full range speaker units SF1 to SF10 in
FIG. 2) are output to the amplification unit 43.
[0074]
In the second embodiment, the coefficients of the mixing unit 53 in the signal processing unit 42
are determined according to the speaker unit arrangement (SF101 to SF1) of the speaker unit 45
and the drive specifications shown in FIG. 6 and the like.
An example of the coefficients of the mixing unit 53 is shown in FIG.
[0075]
The channels (output channels) of the output signals for the full-range speaker units SF101 to
SF110 in FIG. 6 are F1 to F10, and the input signals are 24 acoustic channels shown in FIGS.
[0076]
As shown in FIG. 9, in the output channel F101, the acoustic channels FL, LFE-1 and TpFL are
used, in the output channel F102, the acoustic channels LFE-1 and FLc are used, and in the
output channel F103, the acoustic channels FC and LFE- 1, using LFE-2 and TpFC, using output
channel F104 using acoustic channel FRc and LFE-2, and using output channel F105 using sound
channel FR, LFE-2 and TpFR, using output channel F106 Using the acoustic channels FL, LFE-1
and BtFL, the output channel F107 uses the acoustic channels LFE-1 and FLc, and the output
channel F108 uses the acoustic channels FC, LFE-1, LFE-2 and BtFC , In force Channel F 109,
using an acoustic channel FRc, and LFE-2, the output channel F110, sound channels FR, LFE-2,
and used BTfr.
[0077]
The amplification unit 43 amplifies the 10-channel output signal from the signal processing unit
42 into a drive signal of the speaker unit, and outputs the amplified signal to the filter unit 44.
[0078]
The filter unit 44 generates a drive signal of 18 channels by applying a filter process (described
later) including a coil, a capacitor, and a resistor to the drive signal of 10 channels from the
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amplification unit 43, and outputs the drive signal to the speaker unit 45. Do.
[0079]
In the speaker unit 45, the eighteen speaker units (full range speaker units SF101 to SF110 and
bass speaker units SL101 to SL108) of FIG. 6 are driven by the drive signal of 18 channels from
the filter unit 44, and sound output is performed.
[0080]
The control unit 48 receives a listener's input to the remote controller 80 as a signal from the
remote controller 80, and outputs a control signal to at least one of the input unit 41, the signal
processing unit 42, and the amplification unit 43.
The instruction of the listener includes power on / off, input switching, volume adjustment,
sound quality switching, virtual surround processing on / off, and the like.
[0081]
Although the speaker unit 45 is configured as shown in FIG. 6, the housing 45x provided with
the full range speaker units SF101 to SF105 and the low frequency speaker units SL101 to
SL104, the full range speaker units SF106 to SF110 and the low frequency speaker units SL105
to SL108 The housing 45y may be divided or may be integrated so as to surround the display
screen 60 as shown in FIG.
The bass speaker unit may be disposed in the middle between two adjacent full-range speaker
units, but two bass speaker units may be disposed equidistantly from the full-range speaker unit.
It is good.
[0082]
In the speaker unit 45, as shown in FIGS. 6 and 7, the full range speaker units SF1 to SF10 are
arranged above and below the display screen 60.
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That is, for the front 11 channels in FIG. 10, the six channels (TpFL, TpFC, TpFR, BtFL, BtFC,
BtFR) correspond to the actual speaker units (SF101, SF103, SF105, SF106, SF108, respectively)
at corresponding positions. For the five channels (FL, FLc, FC, FRc, FR) reproduced from the SF
110) and to which the actual speaker unit is not associated, the actual speaker units (for
example, the speaker unit SF101 for the FL) are located at the upper and lower positions
respectively. And by playing back the same sound pressure from SF 106), when listening from
the upper and lower real speaker units equidistantly, sounds can be felt from the middle point of
the straight line connecting the upper and lower speaker units, To FL, FLc, FC, FRc, FR Also I feel
like have come up with a sound from the corresponding location on the screen by.
[0083]
In the arrangement shown in FIG. 6, one bass speaker unit compensates for the bass portion of
the full-range speaker units at the four corners. Therefore, it is preferable to compensate the bass
of the corresponding output channel in advance.
Specifically, an equalizer is newly provided in the signal processing unit 42, and the sound
pressure shortage of the bass can be prevented by increasing the bass of the output channel.
[0084]
FIG. 8 is a schematic view showing a configuration example of an amplification unit, a filter unit,
and a speaker unit in the second embodiment.
As shown in FIG. 8, in the second embodiment, the input terminal of the channel Fi (i = 101, 103,
106, 108) is connected to the input terminal of the amplifier Bi, and the output terminal of the
amplifier Bi is connected via the capacitor Ci. It is connected to the positive input terminal of the
speaker unit SFi, and connected to the positive input terminal of the speaker unit SLi via the coil
Li.
Also, the input terminal of channel F (i + 1) is connected to the input terminal of amplifier B (i +
1) via inverter IV, and the output terminal of amplifier B (i + 1) is connected to speaker unit SF
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via capacitor C (i + 1). It connects with the negative input terminal of speaker unit SLi while
connecting with the negative input terminal of i + 1). Each amplifier is operated on the basis of
GND, and the negative input terminal of the speaker unit SFi and the positive input terminal of
the speaker unit SF (i + 1) are connected to GND. The inverter IV operates such that the output of
the amplifier connected with the inverter is opposite in phase with respect to the GND when
compared with the output when the inverter is not connected.
[0085]
Also, the input terminal of channel Fj (j = 102, 104, 107, 109) is connected to the input terminal
of amplifier Bj via inverter IV, and the output terminal of amplifier Bj is negative for speaker unit
SFj via capacitor Cj. It is connected to the input terminal and connected to the negative input
terminal of the speaker unit SLj via the coil Lj. Also, the input terminal of channel F (j + 1) is
connected to the input terminal of amplifier B (j + 1), and the output terminal of amplifier B (j +
1) is the positive input of speaker unit SF (j + 1) via capacitor C (j + 1) It is connected to the
terminal and connected to the positive input terminal of the speaker unit SLj. Each amplifier is
operated on the basis of GND, and the positive input terminal of the speaker unit SFj and the
negative input terminal of the speaker unit SF (j + 1) are connected to GND.
[0086]
In this way, the bass speaker unit can be driven by the addition signal of each of the adjacent fullrange speaker units.
[0087]
The filter unit 44 is a filter composed of only passive elements, and is generally called a speaker
unit network.
Although FIG. 8 is configured with a first order filter, any order filter may be configured. Only the
high pass filter portion connecting the full range speaker unit may be secondary. In this case, the
increase in amplitude of the full range speaker unit due to the bass signal can be effectively
suppressed. Although the resistors are not shown in FIG. 8, it goes without saying that the
resistors can be used to adjust the efficiency of the speaker unit. It is also effective to adjust the
impedance of the speaker unit for the purpose of adjusting the output sound pressure to the
input voltage of the speaker unit.
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[0088]
According to the acoustic device 40, the processing channel from the signal processing unit 42
to the amplification unit 43 can be reduced, and then the amplitude of the full range speaker unit
can be suppressed, so that an acoustic device with small distortion can be realized.
[0089]
Third Embodiment The speaker unit 45 (see FIGS. 6 and 7) shown in the second embodiment can
also be driven using the signal processing unit 22 and the amplification unit 23 shown in the
first embodiment.
In that case, the problem of the single bass speaker unit for the full-range speaker units at the
four corners can be solved by changing the mixing ratio of the mixing unit 33.
[0090]
The speaker unit 25 described in the first embodiment can also be driven using the amplification
unit 43 and the filter unit 44 described in the second embodiment. In that case, the problem that
the number of bass speaker units with respect to the full-range speaker units at four corners as
described in the second embodiment is one does not occur.
[0091]
[Summary] As described above, the audio device according to aspect 1 of the present invention
includes three or more main speaker units (full-range speaker units SF1 to SF3, etc.) aligned
outside the display screen, and reproduces input signals of a plurality of channels. Audio device
(20, 40), which includes two or more sub-speaker units (bass speaker units SL1 to SL2, etc.), each
sub-speaker unit being disposed in a gap between two adjacent main speaker units, The subspeaker unit is configured to reproduce a signal obtained from a frequency component less than
the threshold value of the output signal corresponding to each of two adjacent main speaker
units.
[0092]
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According to the above configuration, the sub-speaker unit for reproducing a signal obtained
from the frequency component less than the threshold value of the output signal corresponding
to each of the two main speaker units is provided in the gap between the two adjacent main
speaker units. Therefore, even if a small and light speaker unit is used for the main speaker unit,
the necessary sound pressure and reproduction band can be secured, and the sound image can
be localized at the intended position.
[0093]
In the acoustic device according to aspect 2 of the present invention, in the aspect 1, in each of
the two main speaker units, a signal obtained by attenuating a frequency component below the
threshold value or another threshold value from the corresponding output signal is reproduced
Configuration.
[0094]
According to the above configuration, the stroke of the main speaker unit can be suppressed and
distortion can be reduced.
[0095]
In the acoustic device according to aspect 3 of the present invention, in the aspect 1, the input
signal of the plurality of channels includes a low frequency signal (LFE-1, etc.) lower than a
predetermined frequency, and the low frequency signal is at least one. It is the structure
reproduced | regenerated by a sub speaker unit.
[0096]
According to the above configuration, the low frequency input signal can be properly
reproduced, and the bass region can be enhanced.
[0097]
In the acoustic device according to aspect 4 of the present invention, in the aspect 1, the output
signal corresponding to each of the two main speaker units is generated using an input signal of
a channel (such as FL) corresponding to the forward sound source of the listener The
configuration is
[0098]
When there are three or more channels of sound sources in front of the listener, the acoustic
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26
device according to aspect 1 is preferable.
[0099]
In the sound device according to aspect 5 of the present invention, in the aspect 1, the output
signal corresponding to each of the two main speaker units is a predetermined input signal of a
channel corresponding to a non-forward sound source (BL or the like) of a listener. This
configuration is generated by further using the processed signal.
[0100]
According to the above configuration, since distortion in the main speaker is suppressed, virtual
surround can be appropriately realized.
[0101]
The sound device according to aspect 6 of the present invention is configured such that, in the
aspect 5, the predetermined signal processing is based on a head-related transfer function.
[0102]
According to the above configuration, virtual surround can be realized more properly.
[0103]
The acoustic device according to aspect 7 of the present invention is configured such that, in
aspect 1, the plurality of channels conform to a three-dimensional multi-channel acoustic system
(22.2 ch).
[0104]
For a three-dimensional multi-channel sound system in which there are three or more channels
for a sound source in front of the listener, the sound device according to aspect 1 is preferable.
[0105]
The present invention is not limited to the above-described embodiment, and embodiments
obtained by appropriately changing the above-described embodiment based on common
technical knowledge and those obtained by combining them are also included in the embodiment
of the present invention.
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[0106]
Reference Signs List 20 sound device 21/41 input unit 22 signal processing unit 23/43
amplification unit 25/45 speaker unit 31/51 volume adjustment unit 32/52 virtual surround
processing unit 33/53 mix unit 34/44 filter unit SF1 to SF12 full-range speaker Unit SF101 to
SF110 Full Range Speaker Unit SL1 to SL12 Bass Speaker Unit SL101 to SL108 Bass Speaker
Unit
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