JP6563744B2 - Sound equipment - Google Patents

Description

  The present invention relates to an acoustic device, and more particularly to an acoustic device having a multi-channel acoustic reproduction function.

  In recent years, acoustic devices that record high-sense sound by recording sound with multiple channels and reproducing sound from speakers arranged so as to surround the viewer are becoming common. Services that deliver 5.1ch or 7.1ch audio via recording media such as broadcast and optical discs, networks, and the like are provided. These surround the viewer with five or seven speakers and perform sound reproduction from behind. Furthermore, a three-dimensional multi-channel sound system has also been proposed in which speakers are installed above and below, and sound is reproduced from above and below.

  As shown in FIGS. 10 (a) to 10 (d) and FIG. 11, the three-dimensional multi-channel sound system (hereinafter abbreviated as 22.2ch) has 9 points for the top layer, 10 points for the middle layer, 3 points for the bottom layer, and bass. This is a system consisting of two acoustic channels and is defined in the ARIB STD-B59 standard (hereinafter referred to as ARIB standard) of Non-Patent Document 1. In 22.2ch, a total of 11 sound channels, 3 points in the top layer, 5 points in the middle layer, and 3 points in the bottom layer as shown in FIGS. 10 and 11, are played in front of the viewer, When displayed, it is possible to make an expression in which the video and the sound image coincide with each other, and the immersive feeling can be enhanced.

  However, when displaying an image forward, the positional relationship between the three acoustic channels FLc, FC, FRc included in the middle layer and the display device becomes a problem. When a speaker unit that displays an image on an acoustically transmissive screen and reproduces these three acoustic channels FLc, FC, and FRc on the back of the screen is installed, it is possible to present a sound image that satisfies the ARIB standard. Since a general liquid crystal display is not a sound transmission type, a speaker cannot be disposed on the back surface thereof, and a speaker that reproduces three acoustic channels FLc, FC, and FRc cannot be disposed at an appropriate position.

  In order to solve this, as shown in FIG. 12, twelve speaker units are arranged so as to surround the periphery of the liquid crystal display LCD, and the three acoustic channels FLc, FC, and FRc included in the middle layer are arranged on the upper side of the screen and A technique has been proposed in which sound is perceived as being played back from the screen by playing from both speaker units installed below (see Patent Document 1 and Non-Patent Document 2).

JP2008-109209 (May 8, 2008)

Radio Industry Association Standard ARIB STD-B59 3D Multi-channel Audio System Studio Standard Standard 12-Loudspeaker System for Three-Dimensional 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

  According to the technique shown in FIG. 12, the sound image of the middle layer arranged in the front can be reproduced using 12 speaker units, and 11 sound source positions can be obtained with respect to the front if the height of the listener is satisfied. Everything can be reproduced. Furthermore, if a virtual surround technique is used in combination, 22.2 ch sound reproduction can be performed in a specific listening area.

  However, when these twelve speaker units are attached to the periphery of the television, there are restrictions on the speaker unit installation due to weight, design, and the like. Due to weight and design constraints, a small-diameter and lightweight speaker unit must be selected, but a small-diameter speaker unit generally has a lower sound pressure than a large-diameter speaker and tends to be inferior in bass reproduction capability. Therefore, both the sound pressure and the reproduction band are insufficient.

  Furthermore, when the above-mentioned virtual surround method is used in combination, it is required that the distortion is small during reproduction. However, since the distortion increases when the speaker unit is operated with a large amplitude, it is necessary to reduce the reproduction sound pressure. Cannot be reproduced with sufficient sound pressure.

  Even with a small-diameter speaker unit, if the playback band is limited to a low frequency, the bass playback capability can be secured. Therefore, these 12 speaker units are made into a multi-way system such as a 2-way configuration, and dedicated speaker units are provided for each band. By providing, the reproduction band can be expanded even when a small-diameter speaker unit is used. However, there is a problem that the number of speaker units to be used increases and sound images are dispersed for each speaker unit constituting the multiway.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an acoustic apparatus that can secure a necessary sound pressure and a reproduction band even when a small and lightweight speaker unit is used.

  An acoustic device that includes three or more main speaker units arranged outside the display screen and reproduces an input signal of a plurality of channels, includes two or more sub speaker units, and each sub speaker unit includes two adjacent main speakers. Each sub-speaker unit is arranged in a gap between the units, and 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.

  In the acoustic device 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 the two main speaker units in a gap between two adjacent main speaker units. Therefore, even if a small and lightweight speaker unit is used as the main speaker unit, the necessary sound pressure / reproduction band can be secured and the sound image can be localized at the intended position.

1 is a block diagram illustrating a configuration of an audio device according to Embodiment 1. FIG. FIG. 3 is a front view illustrating a configuration of a speaker unit according to the first embodiment. 4 is a table showing a relationship between an output channel of the audio device of Embodiment 1 and a 22.2 ch audio channel. (A) (b) is a table | surface which shows the filter system of each output channel. It is a block diagram which shows the structure of the audio equipment of Embodiment 2. 6 is a front view illustrating a configuration of a speaker unit according to Embodiment 2. FIG. FIG. 6 is a front view illustrating another configuration of the speaker unit according to the second embodiment. 6 is a schematic diagram illustrating a filter configuration of Embodiment 2. FIG. It is a table | surface which shows the relationship between the output channel of the audio equipment of Embodiment 2, and the 22.2ch audio channel. (A)-(d) is a schematic diagram which shows arrangement | positioning of a 22.2ch sound source (acoustic channel). It is a table | surface which shows the acoustic channel name of 22.2ch, and its label. It is a schematic diagram which shows the 22.2ch reproduction | regeneration method disclosed by the nonpatent literature 2. FIG.

  The embodiment of the present invention will be described below with reference to FIGS.

  Hereinafter, embodiments of the present invention will be described in detail. However, as long as there is no specific description, the structure described in this embodiment is not only intended to limit the scope of the present invention, but is merely an illustrative example. In the following description, “sound” refers to all sounds handled by acoustic products, and includes human voices, background sounds, and musical sounds.

Embodiment 1
(Configuration of sound device)
FIGS. 1A and 1B are block diagrams illustrating the configuration of the acoustic device according to the first embodiment. 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. And a control unit 28 for performing audio output by reproducing an output signal obtained by subjecting an input signal from the external device 70 to signal processing or the like. 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.

  As shown in FIG. 2, the speaker unit 25 includes twelve full-range speaker units (main speaker units) SF1 to SF12 and twelve low-frequency speaker units (sub-speaker units) SL1 that surround the rectangular display screen 60. SL12 is provided. The full-range speaker unit is configured to reproduce from low to high sounds with one speaker unit, and the low-frequency speaker unit is configured to suitably reproduce low sounds, for example, The diameter of the bass speaker unit is designed to be larger than that 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. Further, the bass speaker unit does not necessarily have to be installed with the diaphragm facing forward, and may be configured such that the diaphragm is installed facing the back and the duct or the like is placed facing forward. In this case, even if a bass speaker unit having a larger diameter is used, the forward apparent area of the speaker portion can be reduced.

  In FIG. 2, speaker units SF1, SF8, SF12, and SF5 are arranged clockwise so as to correspond to the four corners of the display screen 60. In addition, speaker units SF2, SF3, and SF4 are arranged in this order from the speaker unit SF1 side in an area that is a gap between the speaker units SF1 and SF5 and that is one outer side of the two long sides of the display screen 60. The speaker units SF9, SF10, and SF11 are arranged in this order from the speaker unit SF8 side in an area that is the gap between SF8 and SF12 and that is on the other outer side of the two long sides of the display screen 60. The speaker unit SF6 is arranged in an area that is the gap between the SF8 and outside one of the two short sides of the display screen 60, and is the gap between the speaker units SF5 and SF8 that is outside the other two short sides of the display screen 60. The speaker unit SF7 is disposed in the region. Furthermore, one bass speaker unit is arranged between two adjacent full-range speaker units.

  As described above, the speaker unit SF1 (corner), SL1, SF2, SL2, SF3, SL3, SF4, SL4, SF5 (corner), SL6, SF7, SL8, SF12 (corner) are clockwise around the display screen 60. ), SL12, SF11, SL11, SF10, SL10, SF9, SL9, SF8 (corner), SL7, SF6, SL5 are arranged. The bass speaker unit is preferably arranged in the middle of the adjacent full-range speaker units. However, it is only necessary that two bass speaker units be arranged at the same distance from the full-range speaker unit. It is not necessary to arrange in the middle of adjacent full-range speaker units.

  Returning to FIG. 1, the input unit 21 receives an input signal from the external device 70 in a wired or wireless manner and outputs it to the signal processing unit 22. The input signal is a digital signal of 24 channels (refer to FIG. 10 and FIG. 11) in a three-dimensional multi-channel acoustic system (hereinafter abbreviated as 22.2 ch) format defined in the ARIB STD-B59 standard of Non-Patent Document 1. 9 channels corresponding to 9 sound sources equidistant from the head, above the listener's head, and in the same layer (middle layer) as the listener's head, 10 channels corresponding to 10 sound sources that are equidistant from each other, 3 channels that are lower than the listener's head (bottom layer) and that correspond to 3 sound sources that are equidistant from the head, and 2 that correspond to the bass effect A channel.

  The 9 channels on the top layer of 22.2ch are the upper left front of the listener, the upper front, the upper right front, and the three channels TpFL, TpFC, TpFR corresponding to the respective sound sources, the upper left of the listener and Two channels of TpSiL and TpSiR corresponding to the sound sources on the upper right side, three channels of TpBL, TpBC, and TpBR corresponding to the sound sources on the listener's diagonally upper left rear, upper back, and upper right diagonally rear, and the listener 1 channel of TpC corresponding to the sound source immediately above.

  The 10 channels for the 22.2ch middle layer are FL, FLc, FC, FRc corresponding to the sound source of the listener's diagonally left front, diagonally front left, front, diagonally right front, and diagonally right front, respectively. , 5 channels of FR, SiL corresponding to the sound sources on the left and right sides of the listener, 2 channels of SiR, and BL corresponding to the sound sources on the left diagonally back, back and right diagonally behind the listener, It consists of 3 channels of BC and BR.

  The three channels of the 22.2 ch bottom layer are composed of BtFL, BtFC, and BtFR corresponding to the sound sources of the listener's diagonally lower left front, lower front, and lower right front downward.

  The two channels corresponding to the bass effect are composed of LFE-1 and LFE-2 that do not specify the sound source position.

  The 22.2ch format input signal can be transmitted with one HDMI (registered trademark) cable and 24 with an analog pin connector cable, but the signal transmission form is not particularly limited. When an HDMI cable is used, a video signal and an audio signal are superimposed, but the audio device 20 extracts and uses only the audio signal, and the video signal is separately connected to a display device. A configuration may be adopted in which only an audio signal is received from the display device via HDMI.

  The signal processing unit 22 processes the input signal (22. 2ch format digital signal) received by the input unit 21 and outputs the processed signal to the amplification unit 23. Specifically, the volume adjusting unit 31 adjusts the level of the input signal, and 11 channels corresponding to the front sound source (TpFL, TpFC, TpFR, FL, FLc, FC, FRc, FR, BtFL, BtFC shown in FIG. 10). , BtFR), two channels (LFE-1, LFE-2) corresponding to the bass signal and the bass effect (low frequency signal below a predetermined frequency), and 11 channels corresponding to the surrounding sound source (non-forward sound source) ( BL, BR, BC, SiL, SiR, TpC, TpBL, TpBR, TpSiL, TpSiR, TpBC) and the 11-channel front signal is output to the mix unit 33, and the 11-channel ambient signal is virtualized. The result is output to the surround processing unit 32.

  The virtual surround processing unit 32 performs virtual surround processing on the 11-channel surrounding signal so that it is perceived as being emitted from a speaker unit that does not exist at a specific listening position, and outputs the signal to the mixing unit 33.

  The mixing unit 33 mixes the 11-channel front signal and the 2-channel bass signal in accordance with the speaker unit arrangement of the speaker unit 25 (see FIG. 2), and further outputs the 11-channel ambient signal subjected to the virtual surround processing. By adding, the output signals of 24 channels (F1 to F12 and L1 to L12) corresponding to the speaker unit arrangement (full range speaker units SF1 to SF12 and bass speaker units SL1 to SL12 in FIG. 2) are obtained, and this is the filter unit 34. Output to.

  The filter unit 34 performs a filtering process in accordance with the corresponding speaker unit on the output signal and outputs the filtered signal to the amplification unit 23. Specifically, band limitation is performed on each speaker unit so as to pass only the assumed frequency band. Further, processing for correcting the reproduction frequency characteristic of each speaker unit may be performed so as to adjust the overall frequency characteristic.

  The amplifying unit 23 amplifies the output signal that has been subjected to the filter processing by the filter unit 34 into a driving signal for the speaker unit and outputs the amplified signal to the speaker unit 25.

  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.

  The control unit 29 receives the listener's input to the remote controller 80 by 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 listener's instruction includes power ON / OFF, input switching, volume adjustment, sound quality switching, virtual surround processing ON / OFF, and the like.

(Operation of sound device)
The operation of the acoustic device will be described below.

  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 activation processing of the acoustic device 20. The activation process is a process in which each part is energized and the mute of the amplifying unit 23 is released when the operation is enabled and the sound can actually be emitted.

  When the activation process is completed, the input unit 21 receives an input signal from the connected external device 70. The input unit 21 can accept a plurality of input signals, but accepts an input signal (selected by the listener) according to the signal from the control unit 28.

  The input unit 21 is compatible with various signal formats, but the input signal received here is a 22.2 ch format audio signal using HDMI 2.0.

  The input unit 21 converts these audio signals into a unified digital signal and outputs it to the signal processing unit 22. Here, the unified digital signal includes, for example, a process of defining the sampling frequency as 48 kHz and converting the sampling frequency to 48 kHz when other input signals are received. Even when an analog signal is received, it is converted into the same format by AD conversion.

  In the signal processing unit 22, first, the volume of the input signal is adjusted by the volume adjustment unit 31. The volume processing unit 31 multiplies the input signal and 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 adjusting unit 31 is located in the vicinity of the 11-channel forward signal corresponding to the 11 sound sources located in front and the 2-channel bass signal corresponding to the bass effect. The 11-channel surrounding signal corresponding to 11 sound sources is separated, the 11-channel forward signal is output to the mixing unit 33, and the 11-channel surrounding signal is output to the virtual surround processing unit 32.

  The virtual surround processing unit 32 performs localization processing and crosstalk filter processing on the surrounding signal.

  In the localization process, the head-related transfer function (HRTF) corresponding to the sound source position viewed from the listener position is convolved with the signals corresponding to the respective positions of the 11 surrounding sound sources viewed from the listener position, and the left and right ears are Combine the signals into two channels corresponding to the input to the road.

  HRTF is a characteristic of a space from a certain position to being input to the listener's ear canal, and reflects a signal influenced by the shape of the human head, shoulders, pinna and the like. By convolution of HRTF, it is possible to give the same characteristics as passing through the space from a certain position to the input to the ear canal. Perceived as if it were a sound that was emitted.

  Here, the sound emitted from a certain position enters the listener's both ears through the space, but the sound emitted from a position different from a certain position is different from the sound emitted from a certain position. Therefore, if the sounds emitted from these two positions are combined, it is possible to generate sounds that enter only one ear of the listener. These processes are referred to herein as crosstalk filter processes.

  Therefore, a crosstalk filter process is performed on the two-channel signals corresponding to the inputs to the left and right ear canals according to the number of speaker units actually used for virtual surround reproduction. As a result, it is possible to obtain the same effect as reproducing the HRTF-processed sound at the listener's ear at a specific position, and whether the surrounding 11 sound sources are actually present at the corresponding positions. In this way, the listener can perceive it.

  The mixing unit 33 mixes the 11-channel front signal and the 2-channel bass signal in accordance with the speaker unit arrangement of the speaker unit 25 (see FIG. 2), and further outputs the 11-channel ambient signal subjected to the virtual surround processing. By adding, the output signals of 24 channels (F1 to F12 and L1 to L12) corresponding to the speaker unit arrangement (full range speaker units SF1 to SF12 and bass speaker units SL1 to SL12 in FIG. 2) are obtained, and this is the filter unit 34. Output to.

  The output signal (digital signal) of 24 channels is subjected to filter processing by the filter unit 34, further amplified to a speaker unit drive signal by the amplifier unit 23, 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 subjected to internal processing to generate an analog signal amplified by a switching operation.

  Hereinafter, the speaker unit 25 will be described.

  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 11 channels in the front of FIG. 10, the eight channels (TpFL, TpFC, TpFR, FL, FR, BtFL, BtFC, BtFR) are the actual speaker units (SF1, SF3, SF5, respectively) at the corresponding positions. SF3, SF7, SF8, SF10, SF12) and three channels (FLc, FC, FRc) that are not associated with the actual speaker units are the actual speaker units at the upper and lower positions (for example, FLc). Is reproduced from the speaker units SF2 and SF9) with the same sound pressure, so that when listening at an equal distance from the upper and lower actual speaker units, the sound is felt from the midpoint of the straight line connecting the upper and lower speaker units. And the corresponding positions on the screen for FLc, Fc, and FRc The sound is felt as out of the.

  The full-range speaker unit is designed to reproduce the entire audible band with a single speaker unit, but in reality, there is a trade-off between the high range and the low range. When it is enriched, the low frequency characteristics are inferior, and when the low frequency characteristics are enhanced, the high frequency characteristics tend to be inferior. In general, a speaker unit having a large diameter is advantageous for low sound reproduction, but is disadvantageous for high sound reproduction, and a small diameter tends to be reversed. Since a larger caliber is advantageous for moving a large amount of air, the larger the caliber, the higher the sound pressure generated.

  When considering a product as a television or a peripheral device, it is common to select a small-diameter speaker unit due to design and weight constraints. Also in each speaker unit (UpperL, etc.) in FIG. 12, a small-diameter speaker unit has to be used due to restrictions on the width allowed as a product. If this is a full-range speaker unit, the low-frequency characteristics are disadvantageous. In addition, if a high sound pressure is to be generated, the diaphragm is greatly displaced, leading to the generation of distortion. In particular, when a low sound is generated with a high sound pressure, the displacement of the diaphragm increases, exceeding the displacement width allowed for the diaphragm, causing a large distortion or damaging the speaker unit.

  Therefore, in the acoustic device 20, a filter is applied to the drive signal applied to the full range speaker unit so as not to increase the displacement of the diaphragm even when the full range speaker unit is used. Arrange the unit to assist bass playback. For this reason, in the speaker unit 25, a bass speaker unit is arranged between two adjacent full-range speaker units.

  The drive signals applied to the full range speaker units SF1 to SF12 are filtered so as to attenuate signals below a threshold value (for example, a value of 100 Hz to 400 Hz). By doing so, the displacement of the diaphragms of the full range speaker units SF1 to SF12 can be reduced to suppress distortion, and the sound image generated from the full range speaker unit can be localized to the full range speaker unit. .

  A signal attenuated from the driving signal of the full-range speaker unit and having a threshold value (for example, a value of 100 Hz to 400 Hz) or less assists sound pressure by reproducing from the bass speaker unit. Specifically, a filter that attenuates a signal equal to or higher than a threshold value (for example, a value of 100 Hz to 400 Hz) is applied to a signal assigned to the full range speaker unit with respect to two bass speaker units adjacent to the full range speaker unit, Apply. By doing in this way, the low sound attenuate | damped with the drive signal of a full range speaker unit can be supplemented. In addition, when two low-frequency speaker units adjacent to the full-range speaker unit are lined up equidistantly on a straight line across the full-range speaker unit, the sound reproduced from the two low-frequency speaker units with the same sound pressure is As a result, the sound is localized on the full range speaker unit, and as a result, it is possible to perform good sound reproduction in which a sound image is localized on the full range speaker unit in a wide band.

  These processes are applied to all full-range speaker units SF1 to SF12. At this time, there is no bass speaker unit arranged on a straight line for the full-range speaker units (SF1, SF5, SF8, SF12) at the four corners, but there is a bass speaker unit in the vicinity of each full-range speaker unit. There is no significant degradation of localization for the full-range speaker unit at the four corners.

  The problem of the sound image localization can be improved by keeping the arrangement of the low-frequency speaker units at an equal distance from the respective full-range speaker units and bringing them closer to the full-range speaker units at the four corners.

  Here, although the attenuation frequencies of the full-range speaker unit and the bass speaker unit are set to approximately 100 Hz to 400 Hz, they do not necessarily need to match. Specifically, a high-pass filter of 150 Hz may be applied to the drive signal of the speaker unit SF3, and a signal obtained by applying a 200 Hz low-pass filter to the drive signal of the speaker unit SF3 may be added to the speaker units SL2 and SL3. In this way, the speaker units SF3, SL2 and SL3 having overlapping reproduction frequency bands are reproduced at the same time, so that the reproduction performance in the low range can be improved. The order of these filters does not need to be high, and may be about 6 db / oct. Each bass speaker unit adds and reproduces a signal from another adjacent full-range speaker unit.

  A general 2-way speaker unit similarly reproduces by dividing the reproduction band into two speaker units. However, a high-frequency speaker unit that reproduces only high sounds is added to the low-frequency speaker unit that is advantageous for low-frequency reproduction, and is shared. The boundary 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.

  In the first embodiment, the coefficients of the mixing unit 33 in the signal processing unit 22 and the settings of the filter unit 34 are set in accordance with the speaker unit arrangement (SF1 to SF12, SL1 to SL12) and the driving specifications of the speaker unit 25 shown in FIG. decide. An example of the coefficient of the mixing unit 33 is shown in FIG. 3, and an example of the setting of the filter unit 34 is shown in FIG.

  Note that the output signal channels (output channels) for the full-range speaker units SF1 to SF12 in FIG. 2 are F1 to F12, and the output signal channels (output channels) for the bass speaker units SL1 to SL12 in FIG. 2 are L1 to L12. The input signals are 24 acoustic channels shown in FIGS.

  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, 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.

  The output channel L1 uses the acoustic channels LFE-1, FLc, and TpFL, the output channel L2 uses the acoustic channels FC, LFE-1, FLc, and TpFC, and the output channel L3 uses 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 uses the acoustic channels FL, LFE-1 , And TpFL, the output channel L6 uses acoustic channels FR, LFE-2, and TpFR, the output channel L7 uses acoustic channels FL, LFE-1, and BtFL, and the output channel L8 uses acoustic channels. FR, LFE-2, and BtFR are used, the output channel L9 uses the acoustic channels LFE-1, FLc, and BtFL, the output channel L10 uses the acoustic channels FC, LFE-1, FLc, and BtFC, and the output channel L11. Uses the acoustic channels FC, FRc, LFE-2, and BtFC, and the output channel L12 uses the acoustic channels FRc, LFE-2, and BtFR.

  Here, as shown in FIGS. 4A and 4B, the output channels F1 to F12 are subjected to a high-pass filter (HPF) having a cutoff frequency of 150 Hz and a filter characteristic of 12 db / oct, and the output channels L1 to L12 are applied to the output channels L1 to L12. LPF (low pass filter) having a cutoff frequency of 120 Hz (threshold) and a filter characteristic of 6 db / oct is applied.

  By doing so, it is possible to realize an acoustic device capable of generating a higher sound pressure in a better frequency band than when a speaker unit is configured using only a full range speaker unit while maintaining sound image localization performance. Further, when the same sound pressure as that formed only by the full-range speaker unit is generated, distortion can be suppressed to a low level. Therefore, when the virtual surround technology or the like is used in combination, the effect can be realized better. When the signal subjected to the virtual surround processing is supplied only to the full range speaker unit, the effect of suppressing the above-described distortion can be satisfactorily exhibited. However, when the signal is also supplied to the bass speaker unit, the behavior of the bass speaker unit changes. However, since it is difficult to localize the bass as intended by the virtual surround technology, there is not much influence.

  If the speaker unit of the speaker unit 25 and the amplifier of the amplifier unit 23 are configured to correspond one-to-one, an amplifier optimized for the speaker unit can be used. Generally, bass speaker units are required to have high input resistance and high drive power, so a powerful 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.

  In FIG. 3, two channels (LFE-1 and LFE-2) corresponding to the bass signal are added to the output channel, and the sound images of LFE-1 and LFE-2 are defined in accordance with the actual speaker unit arrangement. Therefore, it is possible to satisfactorily reproduce a signal in a band that has a relatively high frequency and affects localization in the bass signal. As a result, since the coincidence between the video and the sound image including the bass signals of LFE-1 and LFE-2 can be measured, it becomes possible to present video / sound with a higher immersion feeling.

[Embodiment 2]
FIGS. 5A and 5B are block diagrams illustrating the configuration of the acoustic device according to the 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, and And a control unit 48 that controls the amplification unit 43, and outputs an audio signal by reproducing an output signal obtained by subjecting an input signal from the external device 70 to signal processing or the like. 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.

  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 arranged above and below a rectangular display screen 60. Specifically, speaker units SF101, SF105, SF110, and SF106 are arranged clockwise so as to correspond to the four corners of the display screen 60. In addition, speaker units SF102, SF103, and SF4 are arranged in this order from the speaker unit SF101 side in a region that is a gap between the speaker units SF101 and SF105 and that is one outer side of the two long sides of the display screen 60. The speaker unit SF107, SF108, and SF109 are arranged in this order from the speaker unit SF106 side in the area outside the other two long sides of the display screen 60, which is the gap between the SF 106 and the SF 110. One bass speaker unit is arranged between the full range speaker units.

  As described above, the speaker unit SF101 (corner), SL101, SF102, SL102, SF103, SL103, SF104, SL104, S10F5 (corner) are arranged on the upper side of the display screen 60 in order from the left. In order from the left, SF 106 (corner), SL 105, SF 107, SL 106, SF 108, SL 107, SF 109, SL 108, SF 110 (corner) are arranged.

  Returning to FIG. 5, the input unit 41 receives an input signal from the external device 70 in a wired or wireless manner, and outputs it to the signal processing unit 42. The input signal is a digital signal of 22.2 ch format (24 channels) shown in FIGS.

  The signal processing unit 42 processes the input signal (22. 2ch format digital signal) received by the input unit 41 and outputs the processed signal to the amplification unit 43. Specifically, the volume adjusting unit 51 adjusts the level of the input signal, and 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) forward signals and bass signals of 2 channels (LFE-1, LFE-2) corresponding to bass effects, and 11 channels (BL, BR, BC, SiL, corresponding to sound sources located in the surroundings) (SiR, TpC, TpBL, TpBR, TpSiL, TpSiR, TpBC). The 11-channel forward signal is output to the mix unit 53, and the 11-channel peripheral signal is output to the virtual surround processing unit 52.

  The virtual surround processing unit 52 performs virtual surround processing on the 11-channel surrounding signal so that it is perceived as being emitted from a speaker unit that does not actually exist at a specific listening position, and outputs the signal to the mixing unit 53.

  The mixing unit 53 mixes the 11-channel front signal and the 2-channel bass signal in accordance with the speaker unit arrangement (described later), and adds the 11-channel surrounding signals subjected to the virtual surround processing, thereby adding 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 amplifying unit 43.

  In the second embodiment, the coefficient of the mix unit 53 in the signal processing unit 42 is determined in accordance with the speaker unit arrangement (SF101 to SF1) and the drive specifications of the speaker unit 45 shown in FIG. An example of the coefficient of the mixing unit 53 is shown in FIG.

  Note that 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.

  As shown in FIG. 9, the output channel F101 uses the acoustic channels FL, LFE-1, and TpFL, the output channel F102 uses the acoustic channels LFE-1 and FLc, and the output channel F103 uses the acoustic channels FC, LFE−. 1, LFE-2 and TpFC are used, the output channel F104 uses the acoustic channels FRc and LFE-2, the output channel F105 uses the acoustic channels FR, LFE-2 and TpFR, and the output channel F106 uses The acoustic channels FL, LFE-1, and BtFL are used, 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.

  The amplifying unit 43 amplifies the 10-channel output signal from the signal processing unit 42 into a driving signal for the speaker unit, and outputs the amplified signal to the filter unit 44.

  The filter unit 44 generates a 18-channel drive signal by filtering the 10-channel drive signal from the amplification unit 43 with a filter (described later) including a coil, a capacitor, and a resistor, and outputs the drive signal to the speaker unit 45. To do.

  In the speaker unit 45, 18 speaker units (full-range speaker units SF101 to SF110 and bass speaker units SL101 to SL108) in FIG. 6 are driven by the 18-channel drive signal from the filter unit 44, and sound is output.

  The control unit 48 receives the 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 listener's instruction includes power ON / OFF, input switching, volume adjustment, sound quality switching, virtual surround processing ON / OFF, and the like.

  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 bass speaker units SL101 to SL104, the full range speaker units SF106 to SF110, and the bass speaker units SL105 to SL108. May be divided, or may be integrated so as to surround the display screen 60 as shown in FIG. The bass speaker unit is preferably arranged in the middle of two adjacent full-range speaker units, but it is only necessary that two bass speaker units be arranged at the same distance from the full-range speaker unit, not necessarily in the middle position. May be.

  In the speaker unit 45, as shown in FIGS. 6 and 7, full-range speaker units SF1 to SF10 are arranged above and below the display screen 60. That is, for the 11 channels in the front of FIG. 10, the six channels (TpFL, TpFC, TpFR, BtFL, BtFC, BtFR) are the actual speaker units (SF101, SF103, SF105, SF106, SF108, The five channels (FL, FLc, FC, FRc, FR) that are reproduced from the SF 110) and are not associated with the actual speaker units are the actual speaker units at the upper and lower positions (for example, the speaker unit SF101 for FL). And the same sound pressure from SF 106), it is possible to feel as if sound is heard from the midpoint of a straight line connecting the upper and lower speaker units when listening at equal distances from the upper and lower actual speaker units. For FL, FLc, FC, FRc, FR Also I feel like have come up with a sound from the corresponding location on the screen by.

  In the arrangement of FIG. 6, the bass speaker units that compensate for the bass parts of the full-range speaker units at the four corners are one by one, so it is preferable to compensate for the bass of the corresponding output channel in advance. Specifically, an equalizer is newly provided in the signal processing unit 42, and the low sound of the low sound can be prevented by increasing the low sound of the output channel.

  FIG. 8 is a schematic diagram illustrating 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. The speaker unit SFi is connected to the plus input terminal of the speaker unit SFi and connected to the plus input terminal of the speaker unit SLi via the coil Li. Further, the input terminal of the channel F (i + 1) is connected to the input terminal of the amplifier B (i + 1) via the inverter IV, and the output terminal of the amplifier B (i + 1) is connected to the speaker unit SF ( Connected to the negative input terminal of i + 1) and connected to the negative input terminal of the speaker unit SLi. Each amplifier is operated based on GND, and the minus input terminal of the speaker unit SFi and the plus input terminal of the speaker unit SF (i + 1) are connected to the GND. The inverter IV operates so that the output of the amplifier to which the inverter is connected is opposite in phase to the GND as compared with the output when the inverter is not connected.

  Further, the input terminal of the channel Fj (j = 102, 104, 107, 109) is connected to the input terminal of the amplifier Bj through the inverter IV, and the output terminal of the amplifier Bj is connected to the minus of the speaker unit SFj through the capacitor Cj. In addition to being connected to the input terminal, it is connected to the negative input terminal of the speaker unit SLj via the coil Lj. Further, the input terminal of the channel F (j + 1) is connected to the input terminal of the amplifier B (j + 1), and the output terminal of the amplifier B (j + 1) is connected to the positive input of the speaker unit SF (j + 1) via the capacitor C (j + 1). In addition to being connected to the terminal, it is connected to the plus input terminal of the speaker unit SLj. Each amplifier is operated based on 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.

  In this way, the bass speaker unit can be driven by the addition signals of the adjacent full-range speaker units.

  The filter unit 44 is a filter composed of only passive elements, and is generally called a speaker unit network. Although the first-order filter is configured in FIG. 8, any order filter may be configured. Only the high-pass filter portion to which the full-range speaker unit is connected may be secondary. In this case, an increase in amplitude of the full range speaker unit due to the bass signal can be effectively suppressed. In addition, although resistance is not illustrated in FIG. 8, it cannot be overemphasized that resistance can be used for the efficiency adjustment of a speaker unit. It is also effective to adjust the impedance of the speaker unit for the purpose of adjusting the output sound pressure with respect to the input voltage of the speaker unit.

  According to the acoustic device 40, the processing channel from the signal processing unit 42 to the amplification unit 43 can be reduced, and the amplitude of the full-range speaker unit can be suppressed to realize an acoustic device with small distortion.

[Embodiment 3]
The speaker unit 45 (see FIGS. 6 and 7) shown in the second embodiment can be driven using the signal processing unit 22 and the amplification unit 23 shown in the first embodiment. In that case, the problem that there is one 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.

  In addition, the speaker unit 25 shown in the first embodiment can be driven using the amplification unit 43 and the filter unit 44 shown in the second embodiment. In that case, there is no problem that there is one bass speaker unit for the full-range speaker unit at the four corners as shown in the second embodiment.

[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.) arranged outside the display screen, and reproduces an input signal of a plurality of channels. (20.40), which includes two or more sub-speaker units (bass speaker units SL1 to SL2, etc.), and each sub-speaker unit is arranged in a gap between two adjacent main speaker units. In the configuration, 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.

  According to the above configuration, the sub speaker unit that reproduces a signal obtained from a 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 lightweight speaker unit is used as the main speaker unit, the necessary sound pressure / reproduction band can be secured and the sound image can be localized at the intended position.

  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 less than the threshold value or another threshold value from the corresponding output signal is reproduced. It is the composition which is done.

  According to the said structure, the stroke of a main speaker unit can be suppressed and distortion can be reduced.

  In the acoustic device according to aspect 3 of the present invention, in the aspect 1, the input signals of the plurality of channels include a low-frequency signal (LFE-1 or the like) less than a predetermined frequency, and the low-frequency signal is at least one It is the structure reproduced | regenerated by a sub speaker unit.

  According to the said structure, a low frequency input signal can be reproduced | regenerated appropriately and a bass region can be enriched.

  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 (FL or the like) corresponding to the listener's front sound source. It is the structure which is done.

  When there are three or more channels for the sound source in front of the listener, the acoustic device according to aspect 1 is preferable.

  In the acoustic 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 predetermined as the input signal of the channel corresponding to the listener's non-forward sound source (BL or the like). It is the structure produced | generated further using the signal which performed the process.

  According to the above configuration, since the distortion at the main speaker can be suppressed, virtual surround can be appropriately realized.

  The acoustic device according to Aspect 6 of the present invention is the configuration according to Aspect 5, wherein the predetermined signal processing is based on a head-related transfer function.

  According to the said structure, virtual surround can be implement | achieved more appropriately.

  The acoustic device according to aspect 7 of the present invention is the structure according to aspect 1, wherein the plurality of channels conform to a three-dimensional multi-channel acoustic system (22.2 ch).

  For the three-dimensional multi-channel sound system having three or more channels for the sound source in front of the listener, the sound device according to aspect 1 is preferable.

  The present invention is not limited to the above-described embodiments, and those obtained by appropriately modifying the above-described embodiments based on common general technical knowledge and those obtained by combining them are also included in the embodiments of the present invention.

20 audio equipment 21/41 input unit 22 signal processing unit 23/43 amplification unit 25/45 speaker unit 31/51 volume control 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

Claims (9)

An audio device that includes three or more main speaker units and reproduces an input signal of a plurality of channels,
With two or more sub-speaker units,
Each said sub speaker unit is disposed in the gap between the two main speaker units adjacent,
The two or more sub-speakers units is a signal including a low frequency component of the output signal corresponding to each of the two main speaker units wherein adjacent attenuates the high frequency components by applying low-pass filter to obtain Including a first sub-speaker unit from which a signal to be reproduced is reproduced,
In each of the two main speaker units, a signal obtained by attenuating the low frequency component by applying a high-pass filter is reproduced. The two or more sub-speaker units include a second sub-speaker unit that reproduces a signal in which a low-frequency component of an output signal corresponding to only one of the two adjacent main speaker units is increased. The acoustic device according to claim 1.   The two or more sub speaker units include the first sub speaker unit and the second sub speaker unit,
  The acoustic apparatus according to claim 2, wherein the second sub speaker unit is adjacent to the main speaker unit adjacent to only one of the sub speaker units. The main speaker unit and the sub speaker unit are arranged on the periphery of the display screen.
The acoustic device according to any one of claims 1 to 3, wherein The plurality of channels include a channel corresponding to a bass effect ,
Channel corresponding to the bass effect, acoustic device according to any one of claims 1, characterized in that it is played in at least one sub speaker units to 4. 6. The acoustic apparatus according to claim 5, wherein the output signals corresponding to the two main speaker units are generated using input signals of channels corresponding to the listener's front sound source. 7. The acoustic apparatus according to claim 6 , wherein output signals corresponding to the two main speaker units are further generated based on input signals of channels corresponding to non-front sound sources of the listener. The acoustic device according to claim 7 , wherein the two main speaker units reproduce a non-forward sound having a sense of localization based on the output signal. The plurality of channels, acoustic device according to any one of claims 1 to 4, characterized in that in line with the three-dimensional multi-channel sound system.

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