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

Abstract

To realize localization of a sound image even with respect to an acoustic component in a low frequency band handled by a subwoofer.SOLUTION: A signal processing device includes a sound source assigning unit 61 that assigns each of a plurality of sound sources corresponding to different positions to one or more subwoofers according to a positional relationship with the sound source among a plurality of subwoofers installed in an acoustic space, and a signal processing unit 62 that generates a plurality of first sound signals respectively corresponding to the plurality of subwoofers from a plurality of sound source signals respectively corresponding to the plurality of sound sources according to a result of the assignment by the sound source assigning unit 61.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to techniques for processing signals representing, for example, sound. [Background technology]

[0002] Techniques have been proposed for controlling the sound field in an acoustic space by assigning multiple sound signals to one or more speakers in the acoustic space (for example, Patent Document 1). Techniques have also been proposed for localizing the sound image of a sound source at a desired position in the acoustic space. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2008-507244 Summary of the Invention [Problem to be solved by the invention]

[0004] A subwoofer, which is responsible for low-frequency sound components, may be installed in an acoustic space together with a main speaker. In conventional acoustic technology, subwoofers are generally used exclusively for enhancing the sense of volume and not for localizing a sound image. However, in situations where the localization of a sound image is particularly emphasized, such as when a sound image moves within an acoustic space, there is a problem that the localization of the sound image by the conventional main speaker alone cannot sufficiently ensure the sense of localization of the low-frequency sound components. In consideration of the above circumstances, one aspect of the present disclosure aims to achieve sound image localization for the low-frequency sound components that are handled by a subwoofer. [Means for solving the problem]

[0005] In order to solve the above problems, a signal processing method according to one aspect of the present disclosure assigns each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in an acoustic space according to their positional relationship with the sound source, and generates a plurality of first sound signals corresponding to the plurality of subwoofers from a plurality of sound source signals corresponding to the plurality of sound sources, respectively, according to the result of the assignment.

[0006] A signal processing device according to one aspect of the present disclosure includes a sound source allocation unit that allocates each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in an acoustic space according to their positional relationship with the sound source, and a signal processing unit that generates a plurality of first sound signals corresponding to the plurality of subwoofers from a plurality of sound source signals corresponding to the plurality of sound sources, respectively, according to the allocation result by the sound source allocation unit.

[0007] A program according to one aspect of the present disclosure causes a computer system to function as a sound source allocation unit that allocates each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in an acoustic space according to their positional relationship with the sound source, and a signal processing unit that generates a plurality of first sound signals corresponding to each of the plurality of subwoofers from a plurality of sound source signals corresponding to each of the plurality of sound sources according to the result of the allocation by the sound source allocation unit.

[0008] An acoustic system according to one aspect of the present disclosure is an acoustic system comprising a plurality of subwoofers installed in an acoustic space and a signal processing device, wherein the signal processing device includes a sound source allocation unit that allocates each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in the acoustic space according to their positional relationship with the sound source, and a first sound processing unit that generates a plurality of first sound signals corresponding to each of the plurality of subwoofers from a plurality of sound source signals corresponding respectively to the plurality of sound sources according to the result of the allocation by the sound source allocation unit. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram illustrating the configuration of an audio system according to a first embodiment. [Figure 2] FIG. 2 is an explanatory diagram regarding the arrangement of a main speaker and a subwoofer. [Figure 3] FIG. 1 is a block diagram illustrating a configuration of a signal processing device. [Figure 4] FIG. 2 is a block diagram illustrating a functional configuration of a signal processing device. [Figure 5] FIG. 2 is a block diagram illustrating a specific configuration of a bass processing unit. [Figure 6] FIG. 10 is an explanatory diagram of the operation of a sound source allocation unit. [Figure 7] FIG. 2 is a block diagram illustrating a specific configuration of an acoustic processing unit. [Figure 8] 10 is a flowchart of a sound field control process. [Figure 9] FIG. 11 is an explanatory diagram of the operation of a sound source allocation unit in the third embodiment. [Figure 10] FIG. 13 is an explanatory diagram of the operation of a sound source allocation unit in the fourth embodiment. [Figure 11] FIG. 10 is a block diagram illustrating a functional configuration of a signal processing device according to a fifth embodiment. [Figure 12] FIG. 2 is a block diagram illustrating a specific configuration of a reverberation processing unit. [Figure 13] FIG. 2 is a block diagram illustrating a configuration of a late reverberation sound generating unit. [Figure 14] FIG. 1 is an explanatory diagram of a unit space. [Figure 15] FIG. 10 is a block diagram illustrating a functional configuration of a signal processing device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] A: First embodiment FIG. 1 is a block diagram illustrating the configuration of an acoustic system 100 according to the first embodiment of the present disclosure. The acoustic system 100 is a playback system that plays back any sound such as voice, music, or sound effects in an acoustic space 10. The acoustic space 10 is an arbitrary space such as an acoustic hall. A listener is located in the acoustic space 10. The listener listens to the reproduced sound by the acoustic system 100.

[0011] The acoustic system 100 of the first embodiment includes a signal supply device 20, a signal processing device 30, M main speakers 41_1 to 41_M, and N subwoofers 42_1 to 42_N (M and N are natural numbers of 2 or more).

[0012] The signal supply device 20 outputs K-channel sound source signals S_1 to S_K corresponding to different sound sources 14_k (k = 1 to K) (K is a natural number of 2 or more). Each sound source 14_k is an arbitrary type of sound source such as an instrument or a singer. Each sound source signal S_k is a digital sound signal representing the waveform of the sound to be radiated from the sound source 14_k.

[0013] For example, a recording system that records the radiated sounds from the K sound sources 14_1 to 14_K, a playback system that can read each sound source signal S_k from a recording medium, or a communication system that receives each sound source signal S_k from an external device via a communication network is exemplified as the signal supply device 20. Note that the signal supply device 20 may be mounted on the signal processing device 30. Also, the signal supply device 20 may be regarded as an external device of the acoustic system 100.

[0014] The signal processing device 30 generates M-channel sound signals X_1 to X_M and N-channel sound signals Y_1 to Y_N by processing the K-channel sound source signals S_1 to S_K supplied from the signal supply device 20. Each sound signal X_m (m = 1 to M) and each sound signal Y_n (n = 1 to N) are signals representing the waveform of sound. The number of channels M of the sound signal X_m is less than the number of channels K of the sound source signal S_k (M < K). Similarly, the number of channels N of the sound signal Y_n is less than the number of channels K of the sound source signal S_k (N < K). However, the number of channels (K, M, N) of each signal may be arbitrarily changed.

[0015] Each sound signal X_m generated by the signal processing device 30 is supplied to one of M main speakers 41_1 to 41_M. The main speaker 41_m is a sound emitting device that emits the sound represented by the sound signal X_m. For convenience, a D / A converter that converts the sound signal X_m from digital to analog is not shown in the figure.

[0016] Each sound signal Y_n generated by the signal processing device 30 is supplied to one of N subwoofers 42_1 to 42_N. The subwoofer 42_n is a sound emitting device that emits the sound represented by the sound signal Y_n. For convenience, a D / A converter that converts the sound signal X_m from digital to analog is not shown. For example, the number N of subwoofers 42_n is less than the number M of main speakers 41_m. However, the numbers M and N can be changed as desired.

[0017] Each subwoofer 42_n is a speaker that reproduces sounds in a lower frequency range than the main speaker 41_m. For example, a speaker that is responsible for a low frequency range of 200 Hz or less (more specifically, 100 Hz or less) is exemplified as the subwoofer 42_n. Each main speaker 41_m is a speaker that reproduces sounds in a higher frequency range and a wider frequency band than the subwoofer 42_n. As described above, the frequency range of the sound signal Y_n is lower than the frequency range of the sound signal X_m. Note that the reproduction frequency range of each main speaker 41_m and the reproduction frequency range of each subwoofer 42_n may overlap with each other.

[0018] 2 is an explanatory diagram regarding the arrangement of main speakers 41_m and subwoofers 42_n. M main speakers 41_1 to 41_M and N subwoofers 42_1 to 42_N are installed in acoustic space 10. M main speakers 41_1 to 41_M are installed around listening area 12 in acoustic space 10. Listening area 12 is an area in acoustic space 10 where a listener may be located. N subwoofers 42_1 to 42_N are similarly installed around listening area 12 in acoustic space 10.

[0019] K sound sources 14_1 to 14_K are set at different positions within the acoustic space 10. Each sound source 14_k is a virtual object set at an arbitrary position within the acoustic space 10. The signal processing device 30 generates M-channel sound signals X_1 to X_M and N-channel sound signals Y_1 to Y_N from the K-channel sound source signals S_1 to S_K so that the sound image of the sound source signal S_k corresponding to each sound source 14_k is localized at the position of that sound source 14_k within the acoustic space 10. Note that each sound signal X_m is an example of a "second sound signal," and each sound signal Y_n is an example of a "first sound signal."

[0020] 3 is a block diagram illustrating the configuration of a signal processing device 30. The signal processing device 30 is realized by an information device such as a personal computer or a tablet terminal. Specifically, the signal processing device 30 includes a control device 31, a storage device 32, a display device 33, and an operation device 34. The signal processing device 30 may be realized by a single device, or may be realized by multiple devices configured separately from each other.

[0021] The control device 31 is composed of one or more processors that control each element of the signal processing device 30. Specifically, the control device 31 is composed of one or more types of processors, such as a CPU (Central Processing Unit), an SPU (Sound Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit).

[0022] The storage device 32 is one or more memories that store programs executed by the control device 31 and data used by the control device 31. The storage device 32 is configured with a known recording medium such as a magnetic recording medium or a semiconductor recording medium. The storage device 32 may also be configured with a combination of multiple types of recording media.

[0023] The storage device 32 of the first embodiment stores K pieces of position information La_1 to La_K. Each piece of position information La_k is information that represents the position (e.g., coordinates) of a sound source 14_k in the acoustic space 10. Each piece of position information La_k is set, for example, in response to an operation by a user via the operation device 34. Note that each piece of position information La_k may be supplied to the signal processing device 30 from an external device such as the signal supply device 20.

[0024] Furthermore, the storage device 32 stores M pieces of position information Lx_1 to Lx_M and N pieces of position information Ly_1 to Ly_N. Each piece of position information Lx_m is information that represents the position (e.g., coordinates) of the main speaker 41_m in the acoustic space 10. Each piece of position information Ly_n is information that represents the position (e.g., coordinates) of the subwoofer 42_n in the acoustic space 10. Each piece of position information Lx_m and each piece of position information Ly_n is set in advance in response to, for example, an operation by the user on the operation device 34.

[0025] The display device 33 displays an image under the control of the control device 31. The operation device 34 is an input device that accepts operations from a user. Note that the display device 33 or the operation device 34, which are separate from the signal processing device 30, may be connected to the signal processing device 30 by wire or wirelessly.

[0026] 4 is a block diagram illustrating an example of the functional configuration of the signal processing device 30. The control device 31 executes a program stored in the storage device 32 to realize a plurality of functions (acoustic processing unit 50, bass processing unit 60) for generating M-channel sound signals X_1 to X_M and N-channel sound signals Y_1 to Y_N from K-channel sound source signals S_1 to S_K.

[0027] The acoustic processing unit 50 generates M-channel sound signals X_1 to X_M corresponding to different main speakers 41_m from K-channel sound source signals S_1 to S_K. The bass processing unit 60 generates N-channel sound signals Y_1 to Y_N corresponding to different subwoofers 42_n from the K-channel sound source signals S_1 to S_K. As described above, the bass processing unit 60 processes the K-channel sound source signals S_1 to S_K before processing by the acoustic processing unit 50 to generate N-channel sound signals Y_1 to Y_N.

[0028] 5 is a block diagram illustrating a specific configuration of the bass processing unit 60. The bass processing unit 60 includes a sound source allocation unit 61, a signal processing unit 62, and a filter unit 63.

[0029] The sound source allocation unit 61 allocates each of K sound sources 14_1 to 14_K corresponding to different positions in the acoustic space 10 to one or more subwoofers 42_n among the N subwoofers 42_1 to 42_N. There is a one-to-one correspondence between the K sound sources 14_1 to 14_K and the K-channel sound source signals S_1 to S_K. Therefore, the allocation of the sound source 14_k to each subwoofer 42_n can also be expressed as the allocation of the sound source signal S_k to each subwoofer 42_n. Specifically, the sound source allocation unit 61 allocates each sound source 14_k to one or more subwoofers 42_n among the N subwoofers 42_1 to 42_N in the acoustic space 10, depending on the positional relationship between the sound source 14_k and the subwoofer 42_n.

[0030] 6 is an explanatory diagram of the operation of the sound source allocation unit 61. The sound source allocation unit 61 of the first embodiment allocates each of K sound sources 14_1 to 14_k to one subwoofer 42_n that is closest to the sound source 14_k among N subwoofers 42_1 to 42_N. Specifically, the sound source allocation unit 61 calculates a distance D between each of the N subwoofers 42_1 to 42_N and the sound source 14_k, and allocates the sound source 14_k (sound source signal S_k) to one subwoofer 42_n among the N subwoofers 42_1 to 42_N that has the shortest distance D from the sound source 14_k. The distance D is, for example, the distance between the position indicated by position information La_k of the sound source 14_k and the position indicated by position information Ly_n of the subwoofer 42_n. The distance D between the sound source 14_k and the subwoofer 42_n is an example of the "positional relationship" between the sound source 14_k and the subwoofer 42_n.

[0031] 5 generates N-channel sound signals y_1 to y_N from K-channel sound source signals S_1 to S_K in accordance with the allocation result by the sound source allocation unit 61. Specifically, the signal processing unit 62 is a matrix mixer in which a plurality of (K×N) amplifier units 64 are arranged in a matrix of K rows and N columns. The sound source signal S_k is supplied to N amplifier units 64 belonging to the k-th row of the signal processing unit 62. The amplifier unit 64 located in the k-th row and n-th column multiplies the sound source signal S_k by a gain αkn and outputs the result. The sound signal y_n is a signal obtained by adding together output signals of the K amplifier units 64 belonging to the n-th column of the signal processing unit 62.

[0032] The gain αkn of the amplifier 64 located in the k-th row and n-th column of the signal processing unit 62 is set according to the result of allocation of each sound source 14_k to each subwoofer 42_n by the sound source allocation unit 61. For example, when one sound source 14_k is allocated to one subwoofer 42_n, the gain αkn of one amplifier 64 in the k-th row among the K amplifiers 64 belonging to the n-th column is set to "1", and the gains α of the remaining (N-1) amplifiers 64 are set to "0".

[0033] The filter unit 63 generates a sound signal Y_n by performing filter processing on each of the N-channel sound signals y_1 to y_N. Specifically, the filter unit 63 of the first embodiment is a low-pass filter that extracts, from the sound signal Y_n, a low-frequency component that can be reproduced by the subwoofer 42_n, as the sound signal Y_n. As explained above, each sound signal Y_n is a signal that represents a low-frequency component that can be reproduced by the subwoofer 42_n. As illustrated in FIG. 1, each sound signal Y_n generated by the bass processing unit 60 is supplied to the subwoofer 42_n.

[0034] 7 is a block diagram illustrating a specific configuration of the acoustic processing unit 50. The acoustic processing unit 50 includes a sound source allocation unit 51 and a signal processing unit 52.

[0035] The sound source allocation unit 51 allocates each of K sound sources 14_1 to 14_K corresponding to different positions in the acoustic space 10 to one or more main speakers 41_m among the M main speakers 41_1 to 41_M. The allocation of the sound source 14_k to each main speaker 41_m can also be expressed as the allocation of the sound source signal S_k to each main speaker 41_m. For example, the sound source allocation unit 51 allocates each sound source 14_k to one or more main speakers 41_m among the M main speakers 41_1 to 41_M in the acoustic space 10 according to the positional relationship with the sound source 14_k.

[0036] For example, the sound source allocation unit 51 allocates each of the K sound sources 14_1 to 14_K to two or more main speakers 41_m that are closest to the sound source 14_k among the M main speakers 41_1 to 41_M. The distance between the sound source 14_k and the main speaker 41_m is, for example, the distance between the position indicated by the position information La_k of the sound source 14_k and the position indicated by the position information Lx_m of the main speaker 41_m. Note that any known technique may be adopted to allocate the sound source 14_k to each main speaker 41_m. For example, a panning process such as VBAP (Vector-Based Amplitude Panning) or DBAP (Distance-Based Amplitude Panning) may be used for allocation by the sound source allocation unit 51.

[0037] 7 generates M-channel sound signals X_1 to X_M from K-channel sound source signals S_1 to S_K in accordance with the allocation result by the sound source allocation unit 51. Specifically, the signal processing unit 52 is a matrix mixer in which a plurality of (K×M) amplifier units 54 are arranged in a matrix of K rows and M columns. The sound source signal S_k is supplied to M amplifier units 54 belonging to the k-th row of the signal processing unit 52. The amplifier unit 54 located in the k-th row and m-th column multiplies the sound source signal S_k by a gain βkm and outputs the result. The sound signal X_m is a signal obtained by adding together output signals of the K amplifier units 54 belonging to the m-th column of the signal processing unit 52.

[0038] 8 is a flowchart of a process (hereinafter referred to as "sound field control process") executed by the signal processing device 30. When the sound field control process starts, the control device 31 acquires position information La_k of each sound source 14_k (S1). The position information La_k of each sound source 14_k is updated at any time in parallel with the playback operation by the acoustic system 100.

[0039] The control device 31 (sound source allocation unit 51) allocates each of the K sound sources 14_1 to 14_K to one or more main speakers 41_m (S2). The control device 31 (signal processing unit 52) ​​generates M-channel sound signals X_1 to X_M from the K-channel sound source signals S_1 to S_K according to the allocation of the sound source 14_k to the main speaker 41_m (S3). The control device 31 (signal processing unit 52) ​​outputs each sound signal X_m to the main speaker 41_m (S4).

[0040] The control device 31 (sound source allocation unit 61) allocates each of the K sound sources 14_1 to 14_K to one or more subwoofers 42_n (S5). The control device 31 (signal processing unit 62) generates N-channel sound signals Y_1 to Y_N from the K-channel sound source signals S_1 to S_K according to the allocation of the sound source 14_k to the subwoofer 42_n (S6). The control device 31 (signal processing unit 62) outputs each sound signal Y_n to the subwoofer 42_n (S7). Note that the order of the processing related to the main speaker 41_m (S2 to S4) and the processing related to the subwoofer 42_n (S5 to S7) may be reversed.

[0041] The control device 31 determines whether a predetermined termination condition is met (S8). The termination condition is, for example, when a user operates the operation device 34 to instruct termination of the sound field control process. If the termination condition is not met (S8: NO), the control device 31 proceeds to step S1. That is, until the termination condition is met, the control device 31 repeats the acquisition of position information La_k (S1), the generation of each sound signal X_m (S2 to S4), and the generation of each sound signal Y_n (S5 to S7). Therefore, the position of the sound image in the acoustic space 10 changes over time in parallel with the reproduction of sound by the acoustic system 100. If the termination condition is met (S8: YES), the control device 31 terminates the sound field control process.

[0042] As described above, according to the first embodiment, N-channel sound signals Y_1 to Y_N corresponding to different subwoofers 42_n are generated from K-channel sound source signals S_1 to S_K corresponding to different sound sources 14_k in accordance with the result of assigning each of K sound sources 14_1 to 14_K to one or more subwoofers 42_n. Therefore, sound image localization can be achieved even for low-frequency sound components handled by the N subwoofers 42_1 to 42_N.

[0043] Incidentally, as a configuration for generating N-channel sound signals Y_1 to Y_N, for example, a configuration (hereinafter referred to as a "comparative example") may be envisioned in which each sound signal Y_n is generated by processing M-channel sound signals X_1 to X_M generated by an acoustic processing unit 50. However, in the comparative example, the sense of localization in the sound signals X_1 to X_M is reduced as a result of signal processing by the acoustic processing unit 50, and further, the sense of localization in the sound signals Y_1 to Y_N is cumulatively reduced as a result of signal processing performed by the bass processing unit 60. Therefore, it is difficult to sufficiently ensure the sense of localization of the sound image perceived by the listener by reproducing the sound signals Y_1 to Y_N.

[0044] In contrast to the comparative example, in the first embodiment, the initial K-channel sound source signals S_1 to S_K used to generate M-channel sound signals X_1 to X_M are also used to generate N-channel sound signals Y_1 to Y_N. That is, each sound source signal S_k before processing by the acoustic processing unit 50 is processed by the bass processing unit 60 (signal processing unit 62). Therefore, compared to the comparative example in which a sound signal Y_n is generated from each sound signal X_m, the listener can clearly perceive the position of the sound image also for the bass sound components reproduced by each subwoofer 42_n.

[0045] In the above description, a configuration in which each sound signal Y_n is generated by processing each sound signal X_m after processing by the acoustic processing unit 50 has been described as a comparative example, but this is not intended to exclude the comparative example from the scope of the present disclosure. In other words, a configuration in which each sound signal Y_n is generated by processing each sound signal X_m after processing by the acoustic processing unit 50 may be similarly adopted in the present disclosure.

[0046] In the first embodiment, each of the K sound sources 14_1 to 14_K is assigned to one subwoofer 42_n that is closest to the sound source 14_k. Therefore, it is possible to localize a sound image for the bass sound components while simplifying the process by which the bass processing unit 60 (signal processing unit 62) generates N-channel sound signals Y_1 to Y_N.

[0047] B: Second embodiment A second embodiment of the present disclosure will be described. Note that, for elements in the following exemplary aspects that have the same functions as those in the first embodiment, the same reference numerals as those in the first embodiment will be used, and detailed descriptions of each will be omitted as appropriate.

[0048] The second embodiment differs from the first embodiment in the process (S5) in which the sound source allocation unit 61 allocates each sound source 14_k to a subwoofer 42_n. The configuration and operation other than the allocation of the sound source 14_k by the sound source allocation unit 61 are the same as those of the first embodiment.

[0049] The sound source allocation unit 61 of the first embodiment allocates each sound source 14_k to the nearest subwoofer 42_n in the acoustic space 10. The sound source allocation unit 61 of the second embodiment allocates each of the K sound sources 14_1 to 14_k to two or more subwoofers 42_n among the N subwoofers 42_1 to 42_N according to the distance D from the sound source 14_k.

[0050] Specifically, for any combination of a sound source 14_k and a subwoofer 42_n, the smaller the distance D between the sound source 14_k and the subwoofer 42_n, the larger the gain αkn set by the sound source allocation unit 61 for each of the N amplifiers 54 belonging to the k-th row in the signal processing unit 62. As described above, the sound source allocation unit 61 of the second embodiment allocates each sound source 14_k to each subwoofer 42_n by DBAP (Distance-Based Amplitude Panning).

[0051] The second embodiment also achieves the same effects as the first embodiment. Furthermore, in the second embodiment, each of the K sound sources 14_1 to 14_K is assigned to two or more subwoofers 42_n according to the distance D between the sound source 14_k and the subwoofer 42_n. Therefore, compared to the first embodiment in which the sound source 14_k is assigned to one subwoofer 42_n, it is possible to generate a sound signal Y_n that allows the perception of a clear sound image for the low-frequency sound components handled by each subwoofer 42_n.

[0052] C: Third embodiment The third embodiment differs from the first embodiment in the process (S5) in which the sound source allocation unit 61 allocates each sound source 14_k to a subwoofer 42_n. The configuration and operation other than the allocation of the sound source 14_k by the sound source allocation unit 61 are the same as those of the first embodiment.

[0053] Fig. 9 is an explanatory diagram of the operation of the sound source allocation unit 61 in the third embodiment. The sound source allocation unit 61 in the third embodiment divides K sound sources 14_1 to 14_K into a plurality of groups G (G1, G2, ...). For example, the sound source allocation unit 61 sets one or more sound sources 14_k that are located close to each other in the acoustic space 10 as one group G. Fig. 9 illustrates a state in which the sound sources 14_1 to 14_3 are divided into group G1, and the sound sources 14_4 to 14_6 are divided into group G2. Note that a known clustering process is used to divide (i.e., group) the K sound sources 14_1 to 14_K.

[0054] The sound source allocation unit 61 allocates one or more sound sources 14_k belonging to each of a plurality of groups G to a subwoofer 42_n according to the positional relationship between the group G and each subwoofer 42_n. Specifically, the sound source allocation unit 61 sets a reference position Gref for each of the plurality of groups G. The reference position Gref for each group G is a representative position of one or more sound sources 14_k belonging to the group G. For example, the point at which the sum of the distances to the one or more sound sources 14_k belonging to the group G is minimum is exemplified as the reference position Gref.

[0055] Specifically, the sound source allocation unit 61 allocates one or more sound sources 14_k belonging to the group G to one subwoofer 42_n, among the N subwoofers 42_1 to 42_N, that is closest to the reference position Gref of the group G. In other words, one or more sound sources 14_k of the group G are allocated to one subwoofer 42_n, among the N subwoofers 42_1 to 42_N, for which the distance D between the reference position Gref of the group G and the position indicated by the position information Ly_n is the smallest.

[0056] The third embodiment also achieves the same effects as the first embodiment. Moreover, in the third embodiment, the allocation of the sound source 14_k to each subwoofer 42_n is controlled for each group G obtained by dividing the K sound sources 14_1 to 14_K. Therefore, compared with a configuration in which the allocation of the K sound sources 14_1 to 14_K to the subwoofer 42_n is controlled individually, the load for allocating the sound source 14_k or generating the sound signal Y_n can be reduced.

[0057] D: Fourth embodiment The fourth embodiment differs from the first embodiment in the process (S5) in which the sound source allocation unit 61 allocates each sound source 14_k to a subwoofer 42_n. The configuration and operation other than the allocation of the sound source 14_k by the sound source allocation unit 61 are the same as those of the first embodiment.

[0058] 10 is an explanatory diagram of the operation of the sound source allocation unit 61 in the fourth embodiment. The storage device 32 in the fourth embodiment stores a sound pressure distribution P_n for each of the N subwoofers 42_1 to 42_N. The sound pressure distribution P_n is a spatial distribution of sound pressure p related to sound waves radiated by the subwoofer 42_n in response to the supply of a predetermined reference signal. Each sound pressure distribution P_n is determined in advance by, for example, actually measuring the sound pressure p in the acoustic space 10. Alternatively, each sound pressure distribution P_n may be determined in advance by a simulation assuming the acoustic space 10. The sound source allocation unit 61 acquires the sound pressure distribution P_n for each of the N subwoofers 42_1 to 42_N from the storage device 32.

[0059] The sound source allocation unit 61 allocates each of the K sound sources 14_1 to 14_K to a subwoofer 42_n selected from the N subwoofers 42_1 to 42_N in accordance with the positional relationship between the sound source 14_k and the sound pressure distribution P_n. Specifically, as illustrated in FIG. 10 , if the sound pressure p at the position (position information La_k) of the sound source 14_k in the sound pressure distribution P_n exceeds a predetermined threshold p0, the sound source allocation unit 61 allocates the sound source 14_k to the subwoofer 42_n of the sound pressure distribution P_n. On the other hand, if the sound pressure p at the position of the sound source 14_k in the sound pressure distribution P_n is below the threshold p0, the sound source 14_k is not allocated to the subwoofer 42_n. As explained above, one sound source 14_k is allocated to one or more subwoofers 42_n whose sound pressure p exceeds the threshold p0.

[0060] The fourth embodiment also achieves the same effects as the first embodiment. Furthermore, in the fourth embodiment, the allocation of the sound source 14_k to each subwoofer 42_n is controlled according to the positional relationship between the sound source 14_k and the sound pressure distribution P_n. Therefore, taking into account the actual acoustic characteristics of the acoustic space 10 in which the N subwoofers 42_1 to 42_N are installed, it is possible to achieve sound image localization for the low-frequency sound components handled by each subwoofer 42_n.

[0061] E: Fifth embodiment 11 is a block diagram illustrating the functional configuration of a signal processing device 30 according to the fifth embodiment. A control device 31 according to the fifth embodiment executes a program stored in a storage device 32 to implement multiple elements related to reverberation (a reverberation processing unit 70, an addition unit 81, an addition unit 82) in addition to the same elements as those in the first embodiment (an acoustic processing unit 50, a bass processing unit 60).

[0062] The reverberation processor 70 generates reverberation signals R_m (R_1 to R_M) corresponding to each of the M main speakers 41_1 to 41_M from the K-channel sound source signals S_1 to S_K. The sound signal X_m generated by the acoustic processor 50 corresponds to a direct sound that directly reaches the listening point from the sound source, while the reverberation signal R_m generated by the reverberation processor 70 corresponds to a reverberation sound that corresponds to the direct sound represented by the sound signal X_m.

[0063] 12 is a block diagram illustrating a specific configuration of the reverberation processing unit 70. The reverberation processing unit 70 includes an early reflection sound generating unit 71, a late reverberation sound generating unit 72, and an adding unit 73.

[0064] The early reflection sound generator 71 generates M-channel early reflection signals Ra_1 to Ra_M from K-channel sound source signals S_1 to S_K. Each early reflection signal Ra_m represents an early reflection sound that reaches the listening point after repeated reflections on the walls of a virtual acoustic space separate from the acoustic space 10. Specifically, the early reflection sound generator 71 generates the early reflection signals Ra_1 to Ra_M by simulating reflections on the walls of the virtual acoustic space using an imaginary sound source corresponding to the sound source 14_k. The generation of early reflection signals Ra_1 to Ra_M using an imaginary sound source is disclosed in, for example, JP 2022-144496 A.

[0065] The late reverberation sound generator 72 generates M-channel late reverberation signals Rb_1 to Rb_M and N-channel reverberation signals Q_1 to Q_N from K-channel sound source signals S_1 to S_K. Each of the late reverberation signals Rb_m and Q_n represents late reverberation sounds that follow the early reflections due to multiple reflections (multiple reflections) on the walls of a virtual acoustic space separate from the acoustic space 10.

[0066] The adder 73 adds the M-channel early reflection signals Ra_1 to Ra_M generated by the early reflection sound generator 71 and the M-channel late reverberation signals Rb_1 to Rb_M generated by the late reverberation sound generator 72. Specifically, the adder 73 generates a reverberation signal R_m (R_1 to R_M) by adding the early reflection signal Ra_m and the late reverberation signal Rb_m.

[0067] As can be understood from the above explanation, the reverberation sound represented by the reverberation signal R_m includes an early reflection sound (early reflection signal Ra_m) and a late reverberation sound (late reverberation signal Rb_m) that follow the direct sound represented by the sound signal X_m. Note that the reverberation signal R_m is an example of a "second reverberation signal."

[0068] 11 adds M-channel sound signals X_1 to X_M generated by the acoustic processing unit 50 and M-channel reverberation signals R_1 to R_M generated by the reverberation processing unit 70. Specifically, the adder 81 generates a sound signal A_m by adding the sound signal X_m and the reverberation signal R_m. That is, the adder 81 generates M-channel sound signals A_1 to A_M corresponding to different main speakers 41_m. Each sound signal A_m is supplied to the main speaker 41_m.

[0069] When the main speakers 41_m emit the sounds represented by the sound signals A_m, the listener in the acoustic space 10 can perceive a sound image of the reproduced sound, which is a direct sound followed by early reflected sounds and late reverberant sounds.

[0070] Fig. 13 is a block diagram illustrating the configuration of the late reverberation sound generation unit 72. The late reverberation sound generation unit 72 includes a space allocation unit 721, a signal processing unit 722, and a signal processing unit 723. As illustrated in Fig. 14, in the signal processing by the late reverberation sound generation unit 72, H (H=8 in Fig. 14) unit spaces 16_1 to 16_H into which the acoustic space 10 is divided are assumed.

[0071] The space allocation unit 721 in FIG. 12 generates H-channel unit signals V_1 to V_H corresponding to different unit spaces 16_h (h=1 to H). Each unit signal V_h is a signal representing a late reverberation sound to be observed in the unit space 16_h. Specifically, the space allocation unit 721 processes K-channel sound source signals S_1 to S_K to generate H-channel unit signals V_1 to V_H. The generation of unit signals V_h corresponding to each unit space 16_h is disclosed in Japanese Patent Application Laid-Open No. 2022-144496.

[0072] The signal processing unit 722 generates M-channel late reverberation signals Rb_1 to Rb_M from the H-channel unit signals V_1 to V_H. Specifically, the signal processing unit 722 is a matrix mixer (not shown) in which a plurality of amplifiers are arranged in a matrix of H rows and M columns. The gain of each amplifier is set according to the position of each sound source 14_k.

[0073] The signal processing unit 723 generates N-channel reverberation signals Q_1 to Q_N from H-channel unit signals V_1 to V_H. Specifically, the signal processing unit 723 is a matrix mixer (not shown) in which a plurality of amplifiers are arranged in a matrix of H rows and N columns.

[0074] The signal processing unit 723 first refers to the position information Ly_n of each subwoofer 42_n to determine whether any of the N subwoofers 42_1 to 42_N is present in each unit space 16_h of the acoustic space 10. If the subwoofer 42_n is present in the unit space 16_h, the signal processing unit 723 outputs the unit signal V_h corresponding to that unit space 16_h as the reverberation signal Q_n of the subwoofer 42_n.

[0075] As described above, the reverberation processor 70 of the fifth embodiment generates reverberation signals Q_n (Q_1 to Q_N) corresponding to the N subwoofers 42_1 to 42_N, respectively, from K-channel sound source signals S_1 to S_K.

[0076] As described above, the reverberation sound represented by the reverberation signal R_m includes early reflection sounds (early reflection signal Ra_m) and late reverberation sounds (late reverberation signal Rb_m). On the other hand, the reverberation sound represented by the reverberation signal Q_n includes late reverberation sounds but does not include early reflection sounds. Note that the reverberation signal Q_n is an example of a "first reverberation signal."

[0077] The adder 82 in Fig. 11 adds together N-channel sound signals Y_1 to Y_N generated by the bass processing unit 60 and N-channel reverberation signals Q_1 to Q_N generated by the reverberation processing unit 70 (signal processing unit 723). Specifically, the adder 82 generates a sound signal B_n by adding the sound signal Y_n and the reverberation signal Q_n. That is, the adder 82 generates N-channel sound signals B_1 to B_N corresponding to different subwoofers 42_n. Each sound signal B_n is supplied to the subwoofer 42_n.

[0078] When the subwoofers 42_n radiate the sounds represented by the sound signals B_n, the listener in the acoustic space 10 can perceive a sound image of reproduced low-frequency sounds consisting of direct sound followed by early reflected sounds and late reverberant sounds.

[0079] The fifth embodiment also achieves the same effects as the first embodiment. In the fifth embodiment, the sound signal Y_n and the reverberation signal Q_n of the reverberation sound are assigned to the subwoofer 42_n. Therefore, it is possible for the listener to perceive a spatial spread due to the reverberation sound (especially the late reverberation sound) for the sounds reproduced by the N subwoofers 42_1 to 42_N.

[0080] Furthermore, in the fifth embodiment, the sound signal X_m and the reverberation signal R_m of the reverberation sound are assigned to the main speaker 41_m. Therefore, it is possible for the listener to perceive the spatial expansion of the reverberation sound in the sounds reproduced by the M main speakers 41_1 to 41_M. Also, in the fifth embodiment, the K-channel sound source signals S_1 to S_K can be used in common to generate the M-channel sound signals X_1 to X_M, the N-channel sound signals Y_1 to Y_N, the M-channel reverberation signals R_1 to R_M, and the N-channel reverberation signals Q_1 to Q_N.

[0081] Furthermore, in the fifth embodiment, reverberation sounds including early reflection sounds and late reverberation sounds are reproduced by the M main speakers 41_1 to 41_M, thereby enabling the listener to effectively perceive a spatial spread including the acoustic effects caused by the early reflections. Late reverberation sounds tend to be less directional than early reflection sounds. On the other hand, low-frequency sound components that the subwoofer 42_n can reproduce tend to be less directional than high-frequency sound components. Therefore, according to the fifth embodiment, in which the reverberation signal Q_n assigned to the subwoofer 42_n is composed of late reverberation sounds, there is an advantage in that sounds including reverberation sounds can be reproduced without excessively reducing the directional sense of the reverberation signal Q_n.

[0082] The configurations and operations of the acoustic processing unit 50 and the bass processing unit 60 in the fifth embodiment are the same as those in the first embodiment. In the fifth embodiment, the sound source allocation unit 61 may use any of the second to fourth embodiments in the process (S5) of allocating each sound source 14_k to a subwoofer 42_n.

[0083] F: Variation Specific modified embodiments that can be added to each of the embodiments exemplified above are exemplified below. Two or more embodiments arbitrarily selected from the following examples may be appropriately combined within the scope of not being mutually contradictory.

[0084] (1) In the above-described embodiments, the sound source 14_k is assigned to the subwoofer 42_n in accordance with the positional relationship between the sound source 14_k and the subwoofer 42_n in the acoustic space 10. However, the configuration and method for assigning the sound source 14_k to each subwoofer 42_n are not limited to the above examples. For example, the sound source assigning unit 61 may assign each sound source 14_k to each subwoofer 42_n (for example, set the gain αkn) in accordance with an operation by a user on the operating device 34.

[0085] In addition, in the above-described embodiments, the sound source 14_k is assigned to the main speaker 41_m in accordance with the positional relationship between the sound source 14_k and the main speaker 41_m in the acoustic space 10. However, the configuration and method for assigning the sound source 14_k to each main speaker 41_m are not limited to the above examples. For example, the sound source assignment unit 51 may assign each sound source 14_k to each main speaker 41_m (for example, set the gain βkm) in accordance with an operation from the user on the operation device 34.

[0086] (2) In the fifth embodiment, the reverberation signal Q_n does not include early reflection sounds. However, the reverberation signal Q_n may include both late reverberation sounds and early reflection sounds.

[0087] (3) As illustrated in Fig. 15, a subwoofer 43 for ensuring a sense of volume in the bass range may be connected to the signal processing device 30. The bass processing unit 90 in Fig. 15 generates a monaural sound source signal by adding K-channel sound source signals S_1 to S_K, and generates a bass signal C by extracting acoustic components in the bass range (for example, 200 Hz or less) from the sound source signal. In other words, the bass signal C corresponds to a low-frequency effect (LFE).

[0088] The bass signal C generated by the bass processing unit 90 is supplied to the subwoofer 43, whereby the bass sound components, which are difficult for the listener to perceive as a sense of direction, are reproduced. According to the configuration of Fig. 15, the subwoofer 43 ensures a sufficient sense of volume in the bass sound range, while the N subwoofers 42_1 to 42_N enable the listener to perceive a sound image of the bass sound components.

[0089] (4) In the above-described embodiments, N subwoofers 42_1 to 42_N are installed around listening area 12 in acoustic space 10, but the positions of N subwoofers 42_1 to 42_N in acoustic space 10 are not limited to the above examples and may be changed as desired. Similarly, in the above-described embodiments, M main speakers 41_1 to 41_M are installed around listening area 12, but the positions of M main speakers 41_1 to 41_M in acoustic space 10 are not limited to the above examples and may be changed as desired. For example, N subwoofers 42_1 to 42_N or M main speakers 41_1 to 41_M may be installed in an area located in one direction with respect to listening area 12, such as a stage in acoustic space 10.

[0090] (5) As illustrated in the examples of the above embodiments, the functions of the signal processing device 30 are realized through cooperation between one or more processors constituting the control device 31 and a program stored in the storage device 32. The program according to the present disclosure may be provided in a form stored on a computer-readable recording medium and installed on a computer. The recording medium may be, for example, a non-transitory recording medium, such as an optical recording medium (optical disk) such as a CD-ROM, but may also include any known type of recording medium, such as a semiconductor recording medium or a magnetic recording medium. Note that a non-transitory recording medium includes any recording medium other than a transitory, propagating signal, and does not exclude volatile recording media. Furthermore, in a configuration in which a distribution device distributes a program via a communication network, the storage medium that stores the program in the distribution device corresponds to the non-transitory recording medium described above.

[0091] G: Notes From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0092] A signal processing method according to one aspect (aspect 1) of the present disclosure assigns each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in an acoustic space according to their positional relationship with the sound source, and generates a plurality of first sound signals corresponding to the plurality of subwoofers from a plurality of sound source signals corresponding to the plurality of sound sources, respectively, according to the result of the assignment.

[0093] According to the above aspect, a plurality of first sound signals corresponding to different subwoofers are generated from a plurality of sound source signals corresponding to different sound sources in accordance with the result of assigning each of a plurality of sound sources (sound source objects) to one or more subwoofers. Therefore, sound image localization can be realized even for the low-frequency sound components handled by the subwoofers.

[0094] "Generation of first sound signals" is, for example, a process of generating multiple first sound signals from multiple sound source signals so that the sound image perceived by a listener from the reproduced sound of the first sound signals by multiple subwoofers is localized to the position of the sound source.

[0095] In a specific example (Aspect 2) of Aspect 1, a plurality of second sound signals corresponding to a plurality of main speakers are further generated from the plurality of sound source signals. In the above aspect, the initial plurality of sound source signals used to generate the plurality of second sound signals are used to generate the plurality of first sound signals. Therefore, compared to a configuration in which a plurality of second sound signals are used to generate a plurality of first sound signals, the listener can clearly perceive the positioning of the sound image, even for the low-frequency sound components handled by the subwoofer.

[0096] "Generation of second sound signals" is, for example, a process of generating multiple second sound signals from multiple sound source signals so that the sound image perceived by the listener from the sound of the second sound signals reproduced by multiple main speakers is localized to the position of the sound source.

[0097] In a specific example (Aspect 3) of Aspect 2, a plurality of first reverberation signals corresponding to the plurality of subwoofers are generated from the plurality of sound source signals, and the plurality of first sound signals and the plurality of first reverberation signals are added together. In the above aspect, the first sound signals and the first reverberation signals representing reverberation sounds are assigned to the subwoofers. Therefore, the listener can perceive a spatial expansion due to reverberation sounds in sounds reproduced by the plurality of subwoofers.

[0098] In a specific example (Aspect 4) of Aspect 3, a plurality of second reverberation signals corresponding to the plurality of main speakers are further generated from the plurality of sound source signals, and the plurality of second sound signals and the plurality of second reverberation signals are added together. In the above aspect, the second sound signals and the second reverberation signals representing reverberation sounds are assigned to the main speakers. Therefore, the listener can perceive a spatial expansion due to reverberation sounds in the sounds reproduced by the plurality of main speakers.

[0099] In a specific example (Aspect 5) of Aspect 4, the reverberation sounds represented by the plurality of second reverberation signals include early reflection sounds and late reverberation sounds corresponding to the sounds represented by the plurality of sound source signals, and the reverberation sounds represented by the plurality of first reverberation signals include the late reverberation sounds but not the early reflection sounds. By reproducing sounds including early reflection sounds and late reverberation sounds using the plurality of main speakers, a listener can effectively perceive a spatial expansion that includes effects due to early reflections. Note that late reverberation sounds tend to be less directional than early reflection sounds. On the other hand, low-frequency sound components that can be reproduced by subwoofer_n tend to be less directional than high-frequency sound components. Therefore, an embodiment in which the first reverberation signal assigned to the subwoofer is composed of late reverberation sounds has the advantage of being able to reproduce sounds including reverberation sounds without excessively reducing the directional sense of the first reverberation signals.

[0100] In a specific example (Aspect 6) of any of Aspects 1 to 5, the allocation of the sound sources involves allocating each of the multiple sound sources to a subwoofer among the multiple subwoofers that is closest to the sound source. In the above aspects, since each of the multiple sound sources is allocated to one subwoofer, it is possible to localize a sound image for low-frequency sound components while simplifying the process of generating multiple first sound signals.

[0101] In a specific example (Aspect 7) of any of Aspects 1 to 5, the allocation of the sound sources involves allocating each of the multiple sound sources to two or more subwoofers among the multiple subwoofers according to the distance from the sound source. In the above aspects, since each of the multiple sound sources is allocated to two or more subwoofers according to the distance between the sound source and the subwoofer, it is possible to generate a first sound signal that allows the perception of a clear sound image for the low-frequency sound components handled by the subwoofers.

[0102] In a specific example (Aspect 8) of any one of Aspects 1 to 5, the allocation of the sound sources involves dividing the multiple sound sources into multiple groups, and allocating one or more sound sources belonging to each of the multiple groups to one or more subwoofers according to the positional relationship between the multiple subwoofers and the group. In the above aspects, the allocation of the sound sources to the subwoofers is controlled in units of groups into which the multiple sound sources are divided. Therefore, compared to a configuration in which the allocation of the multiple sound sources to the subwoofers is controlled individually for each of the multiple sound sources, the load for allocating the sound sources or generating the first sound signal is reduced.

[0103] In a specific example (Aspect 9) of any of Aspects 1 to 5, the allocation of the sound sources involves obtaining a sound pressure distribution for each of the plurality of subwoofers, and allocating each of the plurality of sound sources to one or more of the plurality of subwoofers according to the positional relationship between the sound source and the sound pressure distribution. In the above aspects, the allocation of the sound sources to each subwoofer is controlled according to the positional relationship between the sound source and the sound pressure distribution. Therefore, it is possible to realize sound image localization for the low-frequency sound components handled by the subwoofers, taking into account the actual acoustic characteristics of the acoustic space in which the plurality of subwoofers are installed.

[0104] A signal processing device according to one aspect (aspect 10) of the present disclosure includes a sound source allocation unit that allocates each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in an acoustic space according to their positional relationship with the sound source, and a signal processing unit that generates a plurality of first sound signals corresponding to each of the plurality of subwoofers from a plurality of sound source signals corresponding to each of the plurality of sound sources according to the result of the allocation by the sound source allocation unit.

[0105] A program according to one aspect (aspect 11) of the present disclosure causes a computer system to function as a sound source allocation unit that allocates each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in an acoustic space according to their positional relationship with the sound source, and a signal processing unit that generates a plurality of first sound signals corresponding to each of the plurality of subwoofers from a plurality of sound source signals corresponding to each of the plurality of sound sources according to the result of the allocation by the sound source allocation unit.

[0106] An acoustic system according to one aspect (aspect 12) of the present disclosure is an acoustic system comprising a plurality of subwoofers installed in an acoustic space and a signal processing device, wherein the signal processing device includes a sound source allocation unit that allocates each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in the acoustic space according to their positional relationship with the sound source, and a first sound processing unit that generates a plurality of first sound signals corresponding to each of the plurality of subwoofers from a plurality of sound source signals corresponding to each of the plurality of sound sources according to the result of the allocation by the sound source allocation unit. [Explanation of symbols]

[0107] 100...acoustic system, 10...acoustic space, 12...listening area, 14_k...sound source, 16_h...unit space, 20...signal supply device, 30...signal processing device, 31...control device, 32...storage device, 33...display device, 34...operation device, 41_m...main speaker, 42_n...subwoofer, 43...subwoofer, 50...acoustic processing unit, 51...sound source allocation unit, 52...signal processing unit, 54...amplification unit, 60...bass processing unit, 61...sound source allocation unit, 62...signal processing unit, 63...filter unit, 64...amplification unit, 70...reverberation processing unit, 71...early reflection sound generation unit, 72...late reverberation sound generation unit, 721...space allocation unit, 722...signal processing unit, 723...signal processing unit, 73...addition unit, 81...addition unit, 82...addition unit, 90...bass processing unit.

Claims

1. assigning each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in the acoustic space in accordance with a positional relationship between the sound source and the subwoofer; generating a plurality of first sound signals corresponding to the plurality of subwoofers from a plurality of sound source signals corresponding to the plurality of sound sources, respectively, according to a result of the allocation; A signal processing method implemented by a computer system.

2. moreover, A plurality of second sound signals corresponding to a plurality of main speakers are generated from the plurality of sound source signals. The signal processing method of claim 1.

3. generating a plurality of first reverberation signals corresponding to the plurality of subwoofers from the plurality of sound source signals; Adding the plurality of first sound signals and the plurality of first reverberation signals. The signal processing method of claim 2.

4. moreover, generating a plurality of second reverberation signals corresponding to the plurality of main speakers from the plurality of sound source signals; Adding the plurality of second sound signals and the plurality of second reverberation signals. The signal processing method of claim 3.

5. the reverberation sounds represented by the plurality of second reverberation signals include early reflection sounds and late reverberation sounds corresponding to the sounds represented by the plurality of sound source signals; The reverberation sounds represented by the plurality of first reverberation signals include the late reverberation sounds and do not include the early reflection sounds.

5. The signal processing method of claim 4.

6. In the allocation of the sound sources, Each of the plurality of sound sources is assigned to a subwoofer among the plurality of subwoofers that is closest to the sound source.

6. A signal processing method according to claim 1.

7. In the allocation of the sound sources, Each of the plurality of sound sources is assigned to two or more subwoofers among the plurality of subwoofers according to the distance from the sound source.

6. A signal processing method according to claim 1.

8. In the allocation of the sound sources, Dividing the plurality of sound sources into a plurality of groups; One or more sound sources belonging to each of the plurality of groups are assigned to one or more subwoofers according to a positional relationship between the plurality of subwoofers and the group.

6. A signal processing method according to claim 1.

9. In the allocation of the sound sources, obtaining a sound pressure distribution for each of the plurality of subwoofers; Each of the plurality of sound sources is assigned to one or more subwoofers among the plurality of subwoofers in accordance with a positional relationship between the sound source and a sound pressure distribution.

6. A signal processing method according to claim 1.

10. a sound source allocation unit that allocates each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in an acoustic space according to a positional relationship between the sound source and the subwoofer; a signal processing unit that generates a plurality of first sound signals corresponding to the plurality of subwoofers from a plurality of sound source signals corresponding to the plurality of sound sources, respectively, according to a result of the allocation by the sound source allocation unit; A signal processing device comprising:

11. a sound source allocation unit that allocates each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in the acoustic space according to a positional relationship between the sound source and the subwoofer; and a signal processing unit that generates a plurality of first sound signals corresponding to the plurality of subwoofers from a plurality of sound source signals corresponding to the plurality of sound sources, respectively, according to a result of the allocation by the sound source allocation unit; A program that makes a computer system function as a

12. A plurality of subwoofers installed in an acoustic space; a signal processing device, The signal processing device includes: a sound source allocation unit that allocates each of a plurality of sound sources corresponding to different positions to one or more subwoofers among a plurality of subwoofers installed in an acoustic space according to a positional relationship between the sound source and the subwoofer; a first sound processing unit that generates a plurality of first sound signals corresponding to the plurality of subwoofers from a plurality of sound source signals corresponding to the plurality of sound sources, respectively, according to a result of the allocation by the sound source allocation unit. Sound system.

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