Signal processing device, signal processing method, and signal processing system

Abstract

To inhibit deterioration in feelings of low frequencies in a sound field to which a wavefront synthesis technology is applied, for example.SOLUTION: A signal processing apparatus includes: an audio signal processing unit configured to perform wavefront synthesis processing for at least part of a plurality of sound source data; a first output unit configured to output N-channel audio signals output from the audio signal processing unit to a first speaker device; a mix processing unit configured to mix the N-channel audio signals output from the audio signal processing unit; and a second output unit configured to output an audio signal output from the mix processing unit to a second speaker device.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a signal processing device, a signal processing method, and a signal processing system. [Background technology]

[0002] 2. Description of the Related Art Wave field synthesis technology is known as a sound field reproduction method in which a wave front of a sound in a sound field is picked up by a plurality of microphones and the sound field is reproduced based on the obtained picked-up sound signals (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication 2016-100613 Summary of the Invention [Problem to be solved by the invention]

[0004] In general, in this field, it is desirable to reproduce an audio signal with as little loss of low-frequency components as possible.

[0005] An object of the present disclosure is to provide a signal processing device, a signal processing method, and a signal processing system having a configuration capable of reproducing low-frequency components of an audio signal. [Means for solving the problem]

[0006] The present disclosure relates to, for example, an audio signal processing unit that performs wave field synthesis processing on at least a portion of the plurality of sound source data; a first output unit that outputs the N-channel audio signals output from the audio signal processing unit to a first speaker device; a mix processing unit that mixes the N-channel audio signals output from the audio signal processing unit; a second output unit that outputs the audio signal output from the mix processing unit to a second speaker device; a filter processing unit that cuts a band below a predetermined frequency included in the N-channel audio signal output from the audio signal processing unit; having an output of the filtering section is provided to a first output section; The second speaker device reproduces an audio signal including at least the cut frequency band. death, The predetermined frequency is set between 100 and 200 Hz. It is a signal processing device.

[0007] The present disclosure also relates to, for example, an audio signal processing unit performing a wave field synthesis process on at least a portion of the plurality of pieces of audio source data; a first output unit that outputs the N-channel audio signals output from the audio signal processing unit to a first speaker device; The mix processing section mixes the N-channel audio signals output from the audio signal processing section, a second output unit that outputs the audio signal output from the mix processing unit to a second speaker device; The filter processing unit cuts a band below a predetermined frequency included in the N-channel audio signal output from the audio signal processing unit, an output of the filtering section is provided to a first output section; The audio signal including at least the cut frequency band is reproduced from the second speaker device. 、 The predetermined frequency is set between 100 and 200 Hz. A signal processing method.

[0008] The present disclosure also relates to, for example, A first speaker device; A second speaker device; a signal processing device to which a first speaker device and a second speaker device are connected; having The signal processing device includes: an audio signal processing unit that performs wave field synthesis processing on at least a portion of the plurality of sound source data; a filter processing unit that cuts a band below a predetermined frequency included in the N-channel audio signals output from the audio signal processing unit; a first output unit that outputs the audio signal output from the filter processing unit to a first speaker device; a mix processing unit that mixes the N-channel audio signals output from the audio signal processing unit; a second output unit that outputs the audio signal output from the mix processing unit to a second speaker device; having The second speaker device reproduces an audio signal including at least the cut frequency band. death, The predetermined frequency is set between 100 and 200 Hz. A signal processing system. [Brief description of the drawings]

[0009] [Figure 1] 1A and 1B are diagrams referred to when explaining an example of the wave field synthesis technique. [Diagram 2] FIG. 2 is a diagram referred to when explaining a configuration example of a signal processing system according to an embodiment of the present disclosure. [Diagram 3] FIG. 3 is a diagram to be referred to when explaining another configuration example of the signal processing system. [Figure 4] FIG. 4 is a diagram referred to when describing a configuration example of a signal processing unit according to an embodiment of the present disclosure. [Diagram 5] FIG. 5 is a diagram illustrating the characteristics of a filter included in a filtering processor according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a diagram referred to when explaining a specific example of the process performed in the mix processing unit according to an embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram referred to when explaining a specific example of the processing performed in the mix processing unit according to an embodiment of the present disclosure. [Figure 8] FIG. 8 is a diagram to be referred to when explaining an example of a GUI used when setting the setting information. [Figure 9]FIG. 9 is a diagram to be referred to when explaining an example of a GUI used when setting the setting information. [Figure 10] FIG. 10 is a diagram to be referred to when explaining an example of a GUI used when setting the setting information. [Figure 11] FIG. 11 is a diagram to be referred to when explaining an example of a GUI used when setting the setting information. [Figure 12] 12A to 12C are diagrams to be referred to when explaining an example of a GUI used when setting setting information. [Figure 13] FIG. 13 is a flowchart showing a process flow when setting predetermined setting information. [Figure 14] FIG. 14 is a diagram for explaining a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The description will be made in the following order. <About Wave Field Synthesis Technology> <One embodiment> <Modification> The embodiments and the like described below are preferred specific examples of the present disclosure, and the contents of the present disclosure are not limited to these embodiments and the like.

[0011] <About Wave Field Synthesis Technology> First, in order to facilitate understanding of this technology, an acoustic technology called wave field synthesis technology will be described. In recent years, wave field synthesis technology that enables new acoustic experiences using a speaker array consisting of multi-channel speakers has been attracting attention. The wave field synthesis technology is a technology (wave field synthesis processing) that physically controls the wave front of sound in a space by controlling the amplitude and phase of each speaker in the speaker array.

[0012] With reference to FIG. 1A and FIG. 1B, a process performed in a signal processing device that realizes the wave field synthesis technology will be described briefly. Sound source data is input to the signal processing device. Sound source metadata includes the sound data itself and metadata describing the playback position (position information) of the sound data, gain, and the like. Such sound source data is also called object audio, and is defined for each object (for example, for each musical instrument or animal) corresponding to the sound source. The signal processing device to which the sound source data is input calculates a playback signal. For example, the signal processing device compares the playback position included in the sound source data with the position of the speaker array in real time, and calculates from which speaker and based on how much amplitude, phase, and the like the sound data of each object is to be played back, thereby obtaining an audio signal for driving the speaker. Then, as shown in FIG. 1B, the obtained audio signal is played back from the corresponding speaker. A synthetic sound field is formed by the sounds played back from the speakers, and sound is played back by wave field synthesis.

[0013] Incidentally, since a multi-channel speaker is used to reproduce an audio signal that has been subjected to wave field synthesis processing, the diameter of each speaker is generally small (for example, about 4 cm). Since the diameter of the speaker is small, there is a limit to the ability to reproduce low frequencies. If an audio signal including low frequencies is reproduced from such a small-diameter speaker, there is a risk that no sound will be produced or abnormal sounds will be reproduced. Therefore, it is possible to consider cutting the low-frequency components of the audio signal to be reproduced in advance, but although this method can prevent the generation of abnormal sounds, the reproduced sound will lack a sense of low frequencies. In addition, it is preferable that various settings can be made regarding the output of the multi-channel audio signal. Taking such points into consideration, a detailed description of the embodiment will be given.

[0014] <One embodiment> [Example of signal processing system configuration] Fig. 2 is a diagram for explaining a configuration example of a signal processing system (signal processing system 1) according to an embodiment of the present disclosure. The signal processing system 1 includes, for example, a first speaker device 10, a second speaker device 20, and a signal processing device 30 that can be connected to the first speaker device 10 and the second speaker device 20 by wire or wirelessly. Fig. 2 shows a state in which the first speaker device 10 and the second speaker device 20 are connected to the signal processing device 30 by wire (cable).

[0015] (First speaker device) The first speaker device 10 (also referred to as an active speaker, etc.) has a plurality of speaker arrays. In this embodiment, the first speaker device 10 has 16 speaker arrays (speaker arrays SPA1, SPA2, SPA16). When it is not necessary to distinguish between the individual speaker arrays, the speaker arrays are collectively referred to as speaker arrays SPA. The speaker array SPA has, for example, eight speakers SP. A channel (ch) number is assigned to each speaker SP. For example, channel numbers 1ch to 8ch are assigned to the eight speakers SP of the speaker array SPA1, and channel numbers 9ch to 16ch are assigned to the eight speakers SP of the speaker array SPA2. Channel numbers are similarly assigned to each speaker SP of the speaker array SPA3 and onward.

[0016] The first speaker device 10 is capable of reproducing N-channel audio signals. Specifically, in this embodiment, the first speaker device 10 is capable of reproducing 128-ch (8×16) audio signals. The 128 speakers SP are supported by, for example, a bar extending in the horizontal direction. As described above, the speakers SP are speakers with a relatively small aperture (for example, 4 cm). The first speaker device 10 reproduces sound data included in sound source data that has been subjected to wave field synthesis processing.

[0017] (Second speaker device) The second speaker device 20 has an external speaker unit SPU. Although one external speaker unit SPU is shown in FIG. 2, the second speaker device 20 may have a plurality of external speaker units SPU. The number of connected external speaker units SPU corresponds to the number of channels (X channels) of the second speaker device 20. The external speaker unit SPU has an external speaker 21 and an external speaker signal processing unit 22. The external speaker signal processing unit 22 performs filtering (processing using a low-pass filter) for limiting the band of the audio signal supplied from the signal processing device 30 to a predetermined frequency or lower (for example, 200 Hz) or lower, DA (Digital to Analog) conversion processing, amplification processing, etc. The audio signal processed by the external speaker signal processing unit 22 is reproduced from the external speaker 21. In this way, the second speaker device 20 is used as a woofer.

[0018] The first speaker device 10 and the second speaker device 20 may be arranged so that their sound emitting surfaces face each other, or so that their sound emitting surfaces are in the same direction. When the first speaker device 10 and the second speaker device 20 are arranged so that their sound emitting surfaces are in the same direction, the respective speaker devices may be arranged so that their sound emitting surfaces are in the same plane, or the respective speaker devices may be arranged so that their sound emitting surfaces are shifted in the depth direction with respect to the listening position.

[0019] (Signal Processing Device) The signal processing device 30 has, for example, an input unit 31, a signal processing unit 32, and an operation input unit 33. A plurality of pieces of sound source data are input to the input unit 31. The sound source data may be supplied to the input unit 31 from a recording medium such as a semiconductor memory or an optical disk, or may be supplied via a network such as the Internet or a wireless LAN (Local Area Network).

[0020] At least a part of the multiple sound source data input to the input unit 31 is sound source data to be subjected to wave field synthesis processing, on which wave field synthesis processing is performed. The multiple sound source data may include sound source data not to be subjected to wave field synthesis processing, on which wave field synthesis processing is not performed. In general, sound source data to be subjected to wave field synthesis processing includes sound source data corresponding to objects with movement, and sound source data not to be subjected to wave field synthesis processing includes sound source data of BGM (Back Ground Music) such as natural environmental sounds, spatial environmental sounds such as noise and sounds. In this embodiment, for convenience of explanation, the sound source data of the object is described as sound source data to be subjected to wave field synthesis processing, and the sound source data of the BGM sound source is described as sound source data not to be subjected to wave field synthesis processing.

[0021] Note that whether or not the sound source data is a target of wave field synthesis processing, that is, whether it is a target or non-target of wave field synthesis processing, is set by, for example, a user. Whether it is a target or non-target of wave field synthesis processing may be automatically set according to the frequency analysis result of the sound data included in the sound source data. In addition, sound source data of objects includes sound source data of objects that do not move or have a small amount of movement. Sound source data of such objects may be set as sound source data that is not a target of wave field synthesis processing. Conversely, sound source data of BGM sound sources may include sound source data that is set as a target of wave field synthesis processing. Whether it is a target or non-target of wave field synthesis processing is described, for example, in metadata included in the sound source data.

[0022] The signal processing unit 32 performs predetermined signal processing on the plurality of pieces of sound source data supplied from the input unit 31. The details of the processing performed by the signal processing unit 32 will be described later.

[0023] The operation input unit 33 is a general term for a configuration for performing operation input. The operation input unit 33 includes a GUI (Graphical User Interface) in addition to physical configurations such as buttons, dials, and levers. For example, setting information is generated by an operation on the operation input unit 33. Details of the setting information will be described later.

[0024] The configuration of the signal processing system 1 can be changed as appropriate. For example, as shown in Fig. 3, the signal processing system (signal processing system 1A) may have a control unit 40A that distributes audio signals to speaker arrays SPA1-8, which are half of the speaker array SPA, and a control unit 40B that distributes audio signals to the remaining speaker arrays SPA9-16. Each control unit is connected to the signal processing device 30. In such a configuration, a synchronization control unit 45 that synchronizes the operations of the control units 40A and 40B is connected to each control unit.

[0025] [Details of the signal processing section] (Example of signal processing unit configuration) Next, the signal processing unit 32 will be described in detail with reference to Fig. 4. As shown in Fig. 4, the signal processing unit 32 has an audio signal processing unit 321. The signal processing unit 32 also has a filter processing unit 322 and a first output unit 323 as a system corresponding to the first speaker device 10. The signal processing unit 32 also has a mix processing unit 324 and a second output unit 325 as a system corresponding to the second speaker device 20. The signal processing unit 32 also has a setting information executing unit 326.

[0026] The sound source data is supplied to the audio signal processing unit 321 via the above-mentioned input unit 31. The sound source data of the object includes the sound data itself and metadata such as position information. The sound data is monaural (1ch) sound data. The sound data after a predetermined gain adjustment is applied to the sound data is supplied to the audio signal processing unit 321 together with position information corresponding to the sound data. The sound source data of the BGM includes the sound data itself and metadata such as output channel information. The sound data is monaural (1ch) sound data. The sound data after a predetermined gain adjustment is applied to the sound data is supplied to the audio signal processing unit 321 together with output channel information corresponding to the sound data.

[0027] The audio signal processing unit 321 performs a predetermined audio signal processing on the supplied audio source data. For example, the audio signal processing unit 321 performs wave field synthesis processing on at least a part of the multiple audio source data, specifically, on audio source data to be subjected to wave field synthesis processing. Specifically, the audio signal processing unit 321 calculates and determines the speaker SP that reproduces audio data among the individual speakers SP and the amplitude, phase, and the like of the audio data to be reproduced by the speaker SP. In this way, the audio signal processing unit 321 functions as an object audio renderer. The audio signal processing unit 321 outputs audio source data that is not to be subjected to wave field synthesis processing without performing wave field synthesis processing. Through the audio signal processing by the audio signal processing unit 321, audio signals of N channels (N=128 in this embodiment) corresponding to the number of channels of the first speaker device 10 are generated. The audio signals of N channels are output to the filter processing unit 322 and the mix processing unit 324, respectively.

[0028] The filter processing unit 322 is, for example, a high-pass filter that cuts the low frequencies of the N-channel audio signals. The filter processing unit 322 is, for example, a first-order IIR (Infinite Impulse Response) filter. The filter processing unit 322 may be, for example, a FIR (Finite Impulse Response) filter. The cutoff frequency of the filter processing unit 322 is set, for example, between 100 and 200 Hz. In this embodiment, the cutoff frequency of the filter processing unit 322 is set to 200 Hz. FIG. 5 shows the characteristics of the filter of the filter processing unit 322 according to this embodiment. By performing the filter processing by the filter processing unit 322, it is possible to prevent the generation of abnormal sounds due to the limit of the reproduction ability of the speaker SP as described above, and to protect the speaker SP. The N-channel audio signals that have been subjected to the filter processing by the filter processing unit 322 are supplied to the first output unit 323.

[0029] The first output unit 323 is, for example, a terminal connected to the first speaker device 10. Audio signals of N channels are output to the first speaker device 10 via the first output unit 323, and the audio signals of N channels are reproduced by the first speaker device 10.

[0030] The N-channel audio signals output from the audio signal processing unit 321 are supplied to the mix processing unit 324. Details of the processing performed by the mix processing unit 324 will be described later. The audio signals processed by the mix processing unit 324 are supplied to a second output unit 325.

[0031] The second output unit 325 is, for example, a terminal connected to the second speaker device 20. An audio signal of X channel is output to the second speaker device 20 via the second output unit 325, and the audio signal of X channel is reproduced by the second speaker device 20.

[0032] The setting information executing unit 326 performs control according to the setting information input via the operation input unit 33. Specifically, the setting information executing unit 326 controls a predetermined function of the signal processing unit 32 so as to execute settings corresponding to the setting information. Note that specific examples of the setting information and the associated specific operations of the setting information executing unit 326 will be described later.

[0033] (About the mix processor) Next, the specific contents of the mix processing performed by the mix processing unit 324 will be described with reference to FIGS.

[0034] For example, as shown in Fig. 6A, when the second speaker device 20 has one external speaker unit SPU1 (1ch), the mix processing unit 324 performs a mix process for mixing all of the N-channel audio signals supplied from the audio signal processing unit 321, that is, a synthesis (e.g., superposition) process of the N-channel audio signals, to generate audio signals of a desired number of outputs (number of channels), as shown in Fig. 7A. By this mix process, for example, a 1-ch audio signal is generated. The generated 1-ch audio signal is reproduced from the external speaker 21 after being processed by the external speaker signal processing unit 22 of the external speaker unit SPU1.

[0035] Also, for example, as shown in FIG. 6B, when the second speaker device 20 has two external speaker units SPU1 and SPU2 (in the case of 2ch), the mix processing unit 324 separates the N-channel audio signals supplied from the audio signal processing unit 321 into two groups, a first half and a second half, as shown in FIG. 7B. For example, grouping is performed based on the number of channels. Specifically, among the N-channel audio signals, audio signals of 1 to 64ch are set as the first half group, and audio signals of 65ch to 128ch are set as the second half group. Then, the first half (N / 2)ch audio signals are mixed to generate a 1ch audio signal. The generated 1ch audio signal is processed by the external speaker signal processing unit 22 of the external speaker unit SPU1, and then reproduced from the external speaker 21 of the external speaker unit SPU1. Also, the second half (N / 2)ch audio signals are mixed to generate a 1ch audio signal. The generated 1ch audio signal is processed by an external speaker signal processing section 22 of the external speaker unit SPU2, and then reproduced from an external speaker 21 of the external speaker unit SPU2.

[0036] In general, when the second speaker device 20 has X-channel external speaker units SPU (SPU1 to SPUX), the mix processing unit 324 separates the N-channel audio signal into N / X-channel audio signals and then performs the mix processing (see FIG. 7C).

[0037] In the signal processing system 1 according to the present embodiment described above, the second speaker device 20 can be used to reinforce the low-frequency components that are a weakness of the speaker array used in the wave field synthesis processing, thereby minimizing the loss of low-frequency feeling and achieving enhanced sound quality and an increased sense of sound spread throughout the entire sound field.

[0038] [Settings information] In the signal processing system 1 according to the present embodiment, various settings are possible. Such settings are performed, for example, by using the operation input unit 33. The operation input unit 33 generates setting information according to the operation input, and supplies the generated setting information to the setting information execution unit 326. The setting information execution unit 326 performs control for executing processing based on the setting information. Such setting information includes, for example, information for setting the output of the second speaker device 20. Specific examples of the setting information include the information shown below. Note that, in the present embodiment, the setting information I1, I3, and I4 correspond to information for setting the output of the second speaker device 20. It is also possible to set a plurality of pieces of setting information.

[0039] (Example of setting information) "Setting information I1" The setting information I1 is information on ON / OFF of the sound source data to be output to the second speaker device 20. The setting information I1 can be set, for example, for each sound source data (whether it is a target or non-target of the wave field synthesis process). The sound source data set to ON as the setting information I1 is mixed by the mix processing unit 324 and then output from the second speaker device 20, and the sound source data set to OFF as the setting information I1 is not output from the audio signal processing unit 321 to the mix processing unit 324 and is not output from the second speaker device 20. The selection of sound source data is performed by the audio signal processing unit 321 under the control of the setting information execution unit 326, for example.

[0040] "Settings information I2" The setting information I2 is information regarding on / off of sound source data (sound source data of a BGM sound source in this embodiment) that is not the target of wave field synthesis processing and is output to the first speaker device 10. The sound source data for which ON is set as the setting information I2 is filtered by the filter processing unit 322 and then output from the first speaker device 10, and the sound source data for which OFF is set as the setting information I2 is not output from the audio signal processing unit 321 to the filter processing unit 322 and is not output from the first speaker device 10. The selection of sound source data is performed by the audio signal processing unit 321 under the control of the setting information execution unit 326, for example.

[0041] "Settings information I3" The setting information I3 is information about equalizer settings set for individual sound source data. Note that the setting information I3 may be information set only for some of the sound source data, not for all of the sound source data. The setting information execution unit 326 supplies sound source data and equalizer setting values ​​corresponding to the setting information I3 to the audio signal processing unit 321. The audio signal processing unit 321 performs equalizer processing on the sound source data corresponding to the setting information I3 based on the setting values ​​indicated in the setting information I3. The equalizer processing is performed by the audio signal processing unit 321 under the control of the setting information execution unit 326, for example.

[0042] "Settings information I4" The setting information I4 is information on settings (adjustments) for the reproduction signal reproduced from the second speaker device 20, specifically, information on settings for at least one of gain adjustment, cutoff frequency, delay, phase, and equalizer. The setting information execution unit 326 supplies the sound source data and equalizer setting values ​​corresponding to the setting information I4 to the mix processing unit 324. The mix processing unit 324, under the control of the setting information execution unit 326, processes the mixed signal based on the setting values ​​indicated in the setting information I4.

[0043] (GUI example) The above-mentioned setting information is set, for example, based on an operation input by a user using a predetermined GUI. The GUI may be displayed on a display of the signal processing device 30, or may be displayed on a device (such as a personal computer or a smartphone) different from the signal processing device 30.

[0044] FIG. 8 is a diagram showing an example of a GUI. A list 51 of sound source data is displayed on the left side of the GUI. The sound source data displayed in list 51 is sound source data that constitutes one piece of content. An appropriate name can be set for each piece of sound source data displayed in list 51. The set name is displayed below the area displayed as "Name." In the example shown in FIG. 8, "Object1," "Object2," ... "Area1" are displayed. Note that "Area" refers to sound source data that undergoes wave field synthesis processing so that the playback area becomes a specific area.

[0045] The characters "Ext.SP" are displayed near the center of the GUI, and check boxes 52 corresponding to each sound source data are displayed below the characters. "Ext.SP" means the second speaker device 20. The check boxes 52 are items for setting the above-mentioned setting information I1. Sound source data with a check in the check box 52 (e.g., "Object3") is set as sound source data to be reproduced from the second speaker device 20. Sound source data with an unchecked check box 52 (e.g., "Object1") is set as sound source data not to be reproduced from the second speaker device 20. The setting information I1 can be set not only for sound source data to be subjected to wave field synthesis processing, but also for sound source data not to be subjected to wave field synthesis processing. In the example shown in FIG. 8, sound source data with a check in the check box 52 (e.g., "BGM1") not to be subjected to wave field synthesis processing is set as sound source data to be reproduced from the second speaker device 20. The sound source data that is not the target of the wave field synthesis process and has the check box 52 not checked (for example, “BGM2”) is set as the sound source data that is not reproduced from the second speaker device 20.

[0046] "AS" is displayed to the left of "Ext.SP". "AS" means an active speaker, specifically, the first speaker device 10. Since all the sound source data of the objects to be subjected to the wave field synthesis processing are reproduced from the first speaker device 10, check boxes are all attached to the positions below the characters "AS" corresponding to the sound source data of each object. For the sound source data asymmetric to the wave field synthesis processing, setting information I2, which is a setting as to whether or not to reproduce from the first speaker device 10, can be set. In the example shown in FIG. 8, the check boxes corresponding to the sound source data of "BGM1" and "BGM2" are checked, so that the sound source data is reproduced from the first speaker device 10. On the other hand, the check box box corresponding to the sound source data of "BGM3" is not checked, so that the sound source data is not reproduced from the first speaker device 10.

[0047] To the right of "AS", a character 54 reading "Gain" is displayed, and a gain for each sound source data can be set. To the right of the character 54, a line extending in the horizontal direction and a black dot on the line are displayed so as to correspond to each sound source data. This display is a volume adjustment display 55. By moving the position of the black dot on the volume adjustment display 55 to the left or right, the volume of each sound source data can be adjusted, for example, between -60db and 24dB. The volume set on the volume adjustment display 55 acts on both the first speaker device 10 and the second speaker device 20. The volume set on the volume adjustment display 55 is set, for example, in a volume adjustment section (not shown) provided in front of the first output section 323 and the second output section 325.

[0048] 9, a volume adjustment display 55A may be displayed on the right side of the volume adjustment display 55. The volume adjustment display 55A is a display for setting a volume that is applied only to the sound source data output from the second speaker device 20. Therefore, only the sound source data with the check box 52 checked can be set using the volume adjustment display 55A. The volume adjustment display 55A may be displayed so as to correspond only to the sound source data with the check box 52 checked.

[0049] To the left of the display "AS", a mark 56 corresponding to each sound source data is displayed. The mark 56 is a mark for setting the setting information I3. For example, when the mark 56 corresponding to the sound source data to be adjusted is clicked, the GUI screen transitions to the screen shown in FIG. 10. The horizontal axis of the screen shown in FIG. 10 indicates frequency (Hz), and the vertical axis indicates gain (dB). The user uses the screen shown in FIG. 10 to appropriately adjust the gain corresponding to the frequency using the operation input unit 33, thereby setting the setting information I3.

[0050] Above the display of "Ext.SP", a display 57 including a triangular mark and the characters "-20dB" is displayed. The display 57 is for adjusting the frequency characteristics of the entire sound field. When the display 57 is clicked, the GUI screen transitions to a screen shown in FIG. 11. In the screen shown in FIG. 11, the horizontal axis indicates frequency (Hz) and the vertical axis indicates gain (dB). The screen shown in FIG. 11 also shows lines L0 to L3. The line L0 indicates the cutoff frequency (for example, 200 Hz) of the second speaker device 20. The line L1 indicates the frequency characteristics of the output of the first speaker device 10. The line L2 indicates the frequency characteristics of the output of the second speaker device 20. The line L3 indicates the frequency characteristics of the entire sound field including the first speaker device 10 and the second speaker device (the characteristics obtained by combining the lines L1 and L2).

[0051] The user sets the setting information I4, thereby adjusting the frequency characteristic of the line L2, and accordingly, the frequency characteristic indicated by the line L3 is made as flat as possible. For example, when the first speaker device 10 and the second speaker device 20 are arranged such that their sound emitting surfaces face each other, the user sets the setting information I4 while listening to sounds between the first speaker device 10 and the second speaker device 20.

[0052] A specific example of a GUI for setting the setting information I4 will be described. As a GUI for adjusting the gain of a specific frequency region, for example, a GUI similar to the GUI shown in FIG. 10 can be applied. In addition, as a GUI for adjusting the phase, a dial-shaped GUI shown in FIG. 12A can be exemplified. The phase is adjusted by rotating the dial-shaped GUI in an appropriate direction. In addition, as a GUI for adjusting the delay, a GUI shown in FIG. 12B can be exemplified. The delay is adjusted by appropriately moving the circle mark shown in FIG. 12B to the left or right. In addition, as a GUI for adjusting the cutoff frequency (crossover frequency), a GUI shown in FIG. 12C can be exemplified. The cutoff frequency is adjusted by appropriately moving the circle mark shown in FIG. 12C to the left or right.

[0053] For example, each time the various settings described above are made, the sound source data can be played back by clicking a play button 61 in the GUI shown in Fig. 8, and the effect of the settings can be confirmed. Also, the GUI shown in Fig. 8 displays a button 62 for stopping playback, a button 63 for pausing playback, a playback time 64, the word "Save" 65 for saving the settings, and the like.

[0054] 13 is a flowchart showing a process flow when setting, for example, the setting information I4. In step ST11, the specification of the second speaker device 20 to be connected is confirmed, and a cutoff frequency according to the specification is set. Then, the process proceeds to step ST12.

[0055] In step ST12, the gain of the audio signal reproduced from the second speaker device 20 is adjusted to an extent that it is possible to recognize that sound is being reproduced from the second speaker device 20. Then, the process proceeds to step ST13.

[0056] In step ST13, for example, a user stands between the first speaker device 10 and the second speaker device 20 and performs phase adjustment. As a result of the phase adjustment, the phase is set to a position where the sound is heard loudest. Then, the process proceeds to step ST14.

[0057] In step ST14, a delay is adjusted while a sound source that produces successive single sounds is being reproduced, and the sound deviation between the first speaker device 10 and the second speaker device 20 is adjusted (corrected). Then, the process proceeds to step ST15.

[0058] In step ST15, the sweep sound is reproduced and the gain of the second speaker device 20 is adjusted. Then, the process proceeds to step ST16.

[0059] In step ST16, the sweep sound is reproduced and the cutoff frequency is finely adjusted. The above-described adjustment processes are repeated as appropriate. Of course, the adjustment processes are not necessarily performed consecutively, and each may be performed independently, or only some of the adjustment processes may be performed.

[0060] As described above, various setting information relating to the output of the second speaker device 20 and the like can be set, so that sound effects can be expanded. For example, by making the setting information I1 configurable, it becomes possible to differentiate between object sound sources, and to create a well-defined sound field. Furthermore, by making it possible to set the setting information I2, it is possible to freely combine on / off of playback from the first speaker device 10 and the second speaker device 20 for sound source data that does not require sound image localization (sound source data that is not subject to wave field synthesis processing), thereby enabling a more natural and atmospheric sound expression. Furthermore, by making the setting information I3 configurable, the preferences of the content creator can be reflected in the sound source data of each individual object. Furthermore, by making it possible to set the setting information I4, it is possible to make the frequency characteristics of the entire sound field flat.

[0061] <Modification> Although one embodiment of the present disclosure has been specifically described above, the contents of the present disclosure are not limited to the above-described embodiment, and various modifications based on the technical concept of the present disclosure are possible. The modifications will be described below.

[0062] As shown in FIG. 14, the signal processing device 30 and an external device (for example, a personal computer 70) may be remotely connected via a network such as the Internet. A dummy head DH equipped with a binaural microphone is placed at a predetermined position (for example, between the first speaker device 10 and the second speaker device 20) in a sound field having the first speaker device 10 and the second speaker device 20. Sound collected by the microphone attached to the dummy head DH is transferred to the personal computer 70 via the network by the signal processing device 30. The above-mentioned GUI is displayed on the personal computer 70. The user performs the above-mentioned various adjustments using the GUI while listening to the sound transferred from the signal processing device 30. Setting information obtained as a result of the adjustments is supplied to the signal processing device 30 via the network and set in the signal processing device 30. With this configuration, even if the user is not in the actual sound field, it is possible to perform adjustments by remote operation similar to those performed when the user is at the actual sound field. This system can also be provided as a sound field adjustment service.

[0063] As described in the above embodiment, natural environmental sounds, spatial environmental sounds, etc. are treated as sound source data that is not subject to wave field synthesis processing, thereby realizing a more natural sound field. Note that classification of sound data as subject to wave field synthesis processing or not can be determined by adding subject / not subject attributes to a program based on the creative intention of the content creator, or can be performed automatically by a program analyzing sound data. As a result of the analysis, for example, sound data with a simple frequency structure or sound data of repeated sounds in which similar waveforms appear multiple times at regular time intervals may be recommended to the user as not subject to wave field synthesis processing.

[0064] In the above-mentioned embodiment, the number of external speaker units SPUs that are more compatible with the contents of the content may be recommended. For example, when the sound source data of a plurality of objects are localized in the sound field and continue to remain stationary, the frequency characteristics of the sound field can be maintained at a high quality, so that a simple number of external speaker units SPUs is recommended as the number of external speaker units SPUs to be installed. On the other hand, in the case of a content in which the sound source data moves in parallel with the speaker array in a time series manner, two external speaker units SPUs are recommended as the number of external speaker units SPUs to be installed so that the second speaker device 20 can also assist in the sense of movement. By performing the signal processing described in the embodiment using two external speaker units SPUs, it becomes possible to express sounds that follow the movement of the object sound source with padding.

[0065] In the above embodiment, an example has been described in which the second speaker device 20 is configured by a woofer external speaker unit SPU, but the second speaker device 20 may be configured by a full-range SP. It is sufficient that the external speaker unit SPU reproduces at least an audio signal of a band that is cut in the system for the first speaker device 10.

[0066] The present disclosure can also be realized by an apparatus, a method, a program, a system, etc. For example, a program that performs the functions described in the above-mentioned embodiments can be made downloadable, and an apparatus that does not have the functions described in the embodiments can download and install the program, thereby enabling the apparatus to perform the control described in the embodiments. The present disclosure can also be realized by a server that distributes such a program. Furthermore, the matters described in each embodiment and modified example can be appropriately combined. Furthermore, the contents of the present disclosure should not be interpreted as being limited by the effects exemplified in this specification.

[0067] The present disclosure may also have the following configurations. (1) an audio signal processing unit that performs wave field synthesis processing on at least a portion of the plurality of sound source data; a first output unit that outputs the N-channel audio signals output from the audio signal processing unit to a first speaker device; a mix processing unit that mixes the N-channel audio signals output from the audio signal processing units; a second output unit that outputs the audio signal output from the mix processing unit to a second speaker device; A signal processing device comprising: (2) a filter processing unit that performs processing to limit the N-channel audio signals output from the audio signal processing unit to a band equal to or lower than a predetermined frequency; An output of the filtering section is supplied to the first output section. A signal processing device as described in (1). (3) The predetermined frequency is set between 100 and 200 Hz. A signal processing device as described in (2). (4) When the second speaker device has an X-channel speaker unit, the mix processing unit performs a mix process after separating the N-channel audio signal into an N / X-channel audio signal. A signal processing device according to any one of (1) to (3). (5) The value of X is set to 1 or 2. A signal processing device according to (4). (6) The mix processing unit separates the N-channel audio signal into N / X-channel audio signals based on the number of channels of the first speaker device. A signal processing device according to (4) or (5). (7) The first speaker device and the second speaker device are connectable to each other. A signal processing device according to any one of (1) to (6). (8) an audio signal processing unit performing a wave field synthesis process on at least a portion of the plurality of pieces of audio source data; a first output unit outputs the N-channel audio signals output from the audio signal processing unit to a first speaker device; a mix processing unit that mixes the N-channel audio signals output from the audio signal processing unit; A second output unit outputs the audio signal output from the mix processing unit to a second speaker device. Signal processing methods. (9) A first speaker device; A second speaker device; a signal processing device to which the first speaker device and the second speaker device are connected; having The signal processing device includes: an audio signal processing unit that performs wave field synthesis processing on at least a portion of the plurality of sound source data; a first output unit that outputs the N-channel audio signals output from the audio signal processing unit to the first speaker device; a mix processing unit that mixes the N-channel audio signals output from the audio signal processing units; a second output unit that outputs the audio signal output from the mix processing unit to the second speaker device; A signal processing system having: [Explanation of symbols]

[0068] 1. Signal Processing System 10. First speaker device 20 Second speaker device 30 Signal processing device 32 Signal processing section 321 Audio signal processing unit 322 Filter processing section 323 First output section 324 Mix Processing Unit 325...Second output section 326 Configuration information execution unit SPA···Speaker Array SP···Speaker SPU: External speaker unit

Claims

1. an audio signal processing unit that performs wave field synthesis processing on at least a portion of the plurality of sound source data; a first output unit that outputs the N-channel audio signals output from the audio signal processing unit to a first speaker device; a mix processing unit that mixes the N-channel audio signals output from the audio signal processing units; a second output unit that outputs the audio signal output from the mix processing unit to a second speaker device; a filter processing unit that cuts a band below a predetermined frequency included in the N-channel audio signals output from the audio signal processing unit; having an output of the filtering unit is supplied to the first output unit; the second speaker device reproduces an audio signal including at least the cut frequency band; The predetermined frequency is set between 100 and 200 Hz. Signal processing device.

2. When the second speaker device has an X-channel speaker unit, the mix processing unit performs a mix process after separating the N-channel audio signal into an N / X-channel audio signal. The signal processing device according to claim 1 .

3. The value of X is set to 1 or 2. The signal processing device according to claim 2 .

4. The mix processing unit separates the N-channel audio signal into N / X-channel audio signals based on the number of channels of the first speaker device. The signal processing device according to claim 2 .

5. The first speaker device and the second speaker device are connectable to each other. The signal processing device according to claim 1 .

6. an audio signal processing unit performing a wave field synthesis process on at least a portion of the plurality of pieces of audio source data; a first output unit that outputs the N-channel audio signals output from the audio signal processing unit to a first speaker device; a mix processing unit that mixes the N-channel audio signals output from the audio signal processing unit; a second output unit outputs the audio signal output from the mix processing unit to a second speaker device; a filter processing unit that cuts a band below a predetermined frequency included in the N-channel audio signal output from the audio signal processing unit; an output of the filtering unit is supplied to the first output unit; an audio signal including at least the cut frequency band is reproduced from the second speaker device; The predetermined frequency is set between 100 and 200 Hz. Signal processing methods.

7. A first speaker device; A second speaker device; a signal processing device to which the first speaker device and the second speaker device are connected; having The signal processing device includes: an audio signal processing unit that performs wave field synthesis processing on at least a portion of the plurality of sound source data; a filter processing unit that cuts a band below a predetermined frequency included in the N-channel audio signals output from the audio signal processing unit; a first output unit that outputs the audio signal output from the filter processing unit to the first speaker device; a mix processing unit that mixes the N-channel audio signals output from the audio signal processing units; a second output unit that outputs the audio signal output from the mix processing unit to the second speaker device; having the second speaker device reproduces an audio signal including at least the cut frequency band; The predetermined frequency is set between 100 and 200 Hz. Signal processing system.

Images