JP6688991B2 - Signal processing method and speaker system - Google Patents

Description

  The present invention relates to a signal processing method and a speaker system, and more particularly to a speaker system that reproduces music in a desired space and a signal processing method thereof.

  For example, Patent Document 1 discloses a sound reproduction system in which a diffuser for diffusing in all directions is attached to the upper surface of a speaker mounted upward, and sound is reflected in all directions in a horizontal plane. As a result, uniform frequency characteristics can be obtained in all directions, and the sound quality is not impaired even when listening at any listening position in the room.

Special table 2006-502657 gazette

  However, in the configuration disclosed in Patent Document 1, if a reflective object such as a wall is present within the range of directivity, a large disturbance occurs in the frequency characteristics due to the effect of the reflected sound, and the sound quality is impaired. There is.

  The present invention has been made in view of the above problems, and an object thereof is to provide a signal processing method and a speaker system that can reduce the influence of reflected sound on acoustic characteristics.

  In order to achieve the above object, a signal processing method according to an aspect of the present invention is a signal processing method performed by a processor included in a speaker system having a plurality of speakers each having a certain directivity. An acoustic characteristic of the plurality of speakers based on the acquisition step of obtaining reflected sound information regarding the influence of the sound reproduced from the plurality of speakers reflected on an object, and the reflected sound information obtained in the obtaining step. And a correction step of correcting the acoustic characteristics of the plurality of speakers using the correction coefficient calculated in the coefficient calculation step.

  Further, in order to achieve the above object, a speaker system according to an aspect of the present invention is a speaker system having a plurality of speakers each having a certain directivity, and using a measurement microphone, Based on the reflected sound information acquisition unit that acquires the reflected sound information regarding the influence of the reproduced sound reflected on the object, and the reflected sound information acquired by the reflected sound information acquisition unit, the acoustic characteristics of the plurality of speakers A coefficient calculation unit that calculates a correction coefficient that is a coefficient to be corrected, and a correction unit that corrects the acoustic characteristics of the plurality of speakers using the correction coefficient calculated by the coefficient calculation unit.

  Note that these general or specific aspects may be realized by a system, method, integrated circuit, computer program, or recording medium, and realized by any combination of the system, method, integrated circuit, computer program, and recording medium. May be done.

  According to the present invention, it is possible to realize a signal processing method and a speaker system capable of reducing the influence of reflected sound on acoustic characteristics.

FIG. 1 is a diagram showing an example of the configuration of the speaker system according to the first embodiment. FIG. 2A is a diagram showing a polar pattern of the speaker alone according to the first embodiment. FIG. 2B is a diagram showing a polar pattern when all four speakers according to the first embodiment are reproduced. FIG. 3 is a diagram showing an example of a positional relationship between the speaker and the wall according to the first embodiment. FIG. 4 is a flowchart showing a signal processing method of the speaker system according to the first embodiment. FIG. 5A is a diagram for explaining a method of estimating the position of the speaker and the shape of the room according to the first embodiment. FIG. 5B is a diagram for explaining a method of estimating the position of the speaker and the shape of the room according to the first embodiment. FIG. 5C is a diagram for explaining a method of estimating the position of the speaker and the shape of the room according to the first embodiment. FIG. 6 is a diagram for explaining an estimation method when the speaker is not arranged parallel to the wall. FIG. 7 is a diagram showing a time response before correction at the position of the measurement microphone according to the first embodiment. FIG. 8 is a diagram showing an example of the correction coefficient according to the first embodiment. FIG. 9 is a diagram showing the corrected time response at the position of the measurement microphone according to the first embodiment. FIG. 10 is an example of a detailed flowchart of S19 shown in FIG. FIG. 11A is a diagram for explaining a method of calculating the correction coefficient of the frequency characteristic. FIG. 11B is a diagram for explaining a method of calculating the correction coefficient of the frequency characteristic. FIG. 12 is a flowchart showing a signal processing method of the speaker system according to the modification of the first embodiment. FIG. 13 is a flowchart showing a signal processing method of the speaker system according to the modification of the first embodiment. FIG. 14 is a diagram for explaining the sound addition processing method according to the modification of the first embodiment. FIG. 15A is a diagram for explaining the sound addition processing method according to the modification of the first embodiment. FIG. 15B is a diagram for explaining the sound addition processing method according to the modification of the first embodiment. FIG. 16 is a diagram showing an example of the configuration of the speaker system according to the second embodiment. FIG. 17 is a diagram showing an example of the configuration of the speaker system according to the third embodiment. FIG. 18 is a flowchart showing a signal processing method of the speaker system according to the third embodiment. FIG. 19 is a diagram showing an example of a display screen of the display device according to the third embodiment. FIG. 20 is a diagram showing a polar pattern of the speaker described in Patent Document 1. FIG. 21 is a diagram for explaining a problem of the speaker having the conventional configuration. FIG. 22 is a diagram showing a polar pattern of the speaker having the conventional configuration shown in FIG. FIG. 23A is a diagram showing a time response of the speaker at the listening position shown in FIG. 21. FIG. 23B is a diagram showing frequency characteristics of the speaker at the listening position shown in FIG.

(Findings that form the basis of the present invention)
For example, a listener who is placed in a desired space such as a room and listens to sounds such as music played by a speaker system that plays music, receives a sound that is good anywhere in the room (a sound that does not impair the sound quality). I want to do it. The sound that is good anywhere in the room corresponds to that the sound reproduced by the speaker system can be heard with uniform acoustic characteristics at a wide listening position in the room.

  The above-mentioned Patent Document 1 discloses a sound reproduction system in which a diffuser for diffusing in all directions is attached to the upper surface of a speaker mounted upward, and sound is reflected in all directions in a horizontal plane. As a result, it is disclosed that a uniform frequency characteristic can be obtained in all directions and the sound quality is not impaired even if the sound is heard at any listening position in the room.

  FIG. 20 is a diagram showing a polar pattern of the speaker described in Patent Document 1. That is, FIG. 20 shows a polar pattern having a shape capable of obtaining uniform directivity in a wide range from the speaker, which indicates that the speaker is omnidirectional.

  Further, in Patent Document 1 described above, when a speaker is placed in front of a wall, the influence of reflection from the wall is taken into consideration, and a unique diffuser shape is used to provide directivity over only a wide range in front. The structure of is also disclosed. With this structure, unnecessary reflection due to the wall on the rear surface of the speaker can be suppressed, and uniform directivity can be obtained in a wide front area. Therefore, if the directivity is within a controlled range, uniform acoustic characteristics can be obtained. It is disclosed that listening is possible.

  However, in the configuration disclosed in Patent Document 1, if a reflective object such as a wall is present within the range of directivity, a large disturbance occurs in the frequency characteristics due to the effect of the reflected sound, and the sound quality is impaired. There is. Hereinafter, a specific description will be given with reference to FIGS. 21 to 23B.

  FIG. 21 is a diagram for explaining a problem of the speaker 92 having the conventional configuration. FIG. 22 is a diagram showing a polar pattern of the speaker 92 having the conventional configuration shown in FIG. FIG. 23A is a diagram showing a time response of the speaker 92 at the listening position shown in FIG. FIG. 23B is a diagram showing frequency characteristics of the speaker 92 at the listening position shown in FIG.

  As shown in FIG. 21, when the speaker 92 having the conventional structure having the polar pattern shown in FIG. 22 is placed near the wall 93 which is a reflective object (reflector), a large distance from the wall 93 is heard at the listening position 94. You will also receive reflected sound.

  Therefore, when there is a wall 93 on the side surface of the speaker 92 as shown in FIG. 21, the direct sound and the reflected sound from the wall 93 arrive at the listening position, so that the time response and the diagram shown in FIG. 23A are obtained. The sound having the frequency characteristic as shown in 23B is received. That is, the sound received at the listening position has a dip at a certain periodic frequency as shown in FIG. 23B. Therefore, depending on the listening position 94, the influence of the reflected sound is great, and as shown in FIG. 23A, the disturbance such as a large dip occurs in the frequency characteristics and uniform acoustic characteristics cannot be obtained, so that the sound quality is deteriorated.

  Further, conventionally, against such a problem, the influence of the reflected sound is reduced by forming the wall 93 with a sound absorbing material such as a sound absorbing material, but such a method cannot be performed easily. There is a problem that it does not exist.

  In view of the above-mentioned circumstances, the inventor can reduce the influence of unnecessary reflected sound from the wall on the acoustic characteristics and obtain good acoustic characteristics regardless of the speaker or the listening position with a simpler configuration. We have conceived a signal processing method and a wide directional speaker system.

  That is, a signal processing method according to one aspect of the present invention is a signal processing method performed by a processor included in a speaker system having a plurality of speakers each having a certain directivity, and a plurality of speakers are measured using a measurement microphone. Is a coefficient that corrects the acoustic characteristics of the plurality of speakers based on the acquisition step of acquiring reflected sound information related to the influence of the sound reproduced from the object reflected on the object, and the reflected sound information acquired in the acquisition step. A coefficient calculation step of calculating a correction coefficient, and a correction step of correcting the acoustic characteristics of the plurality of speakers using the correction coefficient calculated in the coefficient calculation step are included.

  As a result, it is possible to realize a signal processing method capable of reducing the influence of reflected sound on the acoustic characteristics.

  Further, for example, the measurement microphone is arranged at the same position as the plurality of speakers, and in the coefficient calculation step, the primary reflection of each of the plurality of speakers included in the reflected sound information acquired in the acquisition step is performed. Based on the sound information, a room shape in which the plurality of speakers are arranged and which is a shape of a room partitioned by a wall, and a speaker position which is a position of the plurality of speakers in the room shape are estimated. The method may include an estimation step and a correction coefficient calculation step of calculating a correction coefficient for each of the plurality of speakers from the room shape and the speaker position estimated in the estimation step.

  Further, for example, in the estimation step, the listening position in the room shape is further estimated from the estimated room shape and the speaker position, and the response time reproduced from the plurality of speakers at the listening position is estimated, The signal processing method further includes a delay time of a speaker facing the wall of the room among the plurality of speakers based on the room shape, the speaker position, the listening position, and the response time estimated in the estimating step. The sound level may be controlled to include a sound addition step of adding a sound at a listening position of sounds reproduced from the plurality of speakers.

  In addition, for example, the speaker system further includes a low-frequency reproduction speaker different from the plurality of speakers, and the signal processing method further includes reproduction by the plurality of speakers and the low-frequency reproduction speaker. The method includes a band division step of dividing the frequency band of the input signal into at least a low frequency band and a high frequency band, and in the band dividing step, the divided high frequency band signal is output to the plurality of speakers. The divided low frequency band signal may be output to the low frequency reproduction speaker.

  Further, for example, in the acquisition step, a reception step of receiving an input of each of the plurality of speakers, a distance between the plurality of speakers in the sound emission direction of the object and the listening position, and reception in the reception step. From the distance and the listening position, the reflected sound information includes a reflected sound estimation step of calculating an estimated reflected sound that is a sound when the sound reproduced from the plurality of speakers is reflected by the object. Good.

  Further, for example, the acoustic characteristics of the plurality of speakers may include at least one of a phase, an acoustic level, and a frequency characteristic of the plurality of speakers.

  Further, for example, a speaker system according to an aspect of the present invention is a speaker system having a plurality of speakers each having a certain directivity, and a sound reproduced from the plurality of speakers is measured by using a measurement microphone. A reflected sound information acquisition unit that acquires reflected sound information related to the influence of the reflected sound, and a correction that is a coefficient that corrects the acoustic characteristics of the plurality of speakers based on the reflected sound information acquired by the reflected sound information acquisition unit. A coefficient calculation unit that calculates a coefficient and a correction unit that corrects the acoustic characteristics of the plurality of speakers using the correction coefficient calculated by the coefficient calculation unit.

  It should be noted that each of the embodiments described below shows one specific example of the present invention. Numerical values, shapes, components, steps, order of steps, and the like shown in the following embodiments are examples and are not intended to limit the present invention. Further, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claim showing the highest concept are described as arbitrary constituent elements. In addition, the contents of each embodiment can be combined.

  Hereinafter, a signal processing method and a speaker system according to one aspect of the present invention will be described.

(Embodiment 1)
[Structure of Speaker System 1]
FIG. 1 is a diagram showing an example of the configuration of a speaker system 1 according to the present embodiment.

  The speaker system 1 shown in FIG. 1 includes an input unit 11, a speaker 12, an amplifier 13, a processor 14, an input signal switching unit 15, and a measurement microphone 16. Note that the speaker 12, the amplifier 13, the input signal switching unit 15, and the measurement microphone 16 are not indispensable configurations, and the speaker system 1 may be configured to include only the input unit 11 and the processor 14. .

  A signal to be reproduced by the speaker system 1 such as a music signal is input to the input unit 11.

  The speaker 12 is composed of a plurality of speakers each having a fixed directivity.

  FIG. 2A is a diagram showing a polar pattern of the speaker alone according to the first embodiment. FIG. 2B is a diagram showing a polar pattern when all four speakers 12a to 12d according to the first embodiment are reproduced.

  In the present embodiment, the speaker 12 includes a speaker 12a, a speaker 12b, a speaker 12c and a speaker 12d. The speaker 12a has a directivity of 90 degrees as shown in FIG. 2A, for example. Similarly, the speaker 12b, the speaker 12c, and the speaker 12d have a directivity of 90 degrees (not shown). Further, the speaker 12 is configured by arranging the speaker 12a, the speaker 12b, the speaker 12c, and the speaker 12d so that the directions of directivity are different. As a result, the speaker 12 has omnidirectionality as shown in FIG. 2B. That is, when the speaker 12a to the speaker 12d are all reproduced, the speaker 12 can reproduce at a uniform sound pressure level in all directions of 360 degrees.

  Note that the speaker 12 is not limited to the case where the speaker 12 is composed of the four speakers as described above. The speaker 12 may have a wide directivity of 180 degrees by arranging two speakers each having a directivity of 90 degrees in different directivity directions. Further, the speaker 12 may have a wide directivity of 270 degrees by being configured by disposing three speakers each having a directivity of 90 degrees in directions of different directivities. That is, the speaker 12 may have any number of speakers as long as it has a wide directivity of 180 degrees or more by arranging a plurality of speakers in different directivity directions.

  The amplifier 13 includes an amplifier corresponding to each of the plurality of speakers. In the present embodiment, the amplifier 13 is composed of an amplifier 13a, an amplifier 13b, an amplifier 13c and an amplifier 13d. The amplifier 13a is connected to the speaker 12a, amplifies the signal output from the processor 14, and transmits the amplified signal to the speaker 12a. The amplifier 13b is connected to the speaker 12b, amplifies the signal output from the processor 14, and transmits the amplified signal to the speaker 12b. The amplifier 13c is connected to the speaker 12c, amplifies the signal output from the processor 14, and transmits the amplified signal to the speaker 12c. The amplifier 13d is connected to the speaker 12d, amplifies the signal output from the processor 14, and transmits the amplified signal to the speaker 12d.

  The measurement microphone 16 is arranged at the same position as the speaker 12, and is used to measure the acoustic characteristics of the speaker 12. In the present embodiment, the measurement microphone 16 is provided in the main body of the speaker 12, and measures the sound reflected by the object reproduced by the speaker 12. Also, the object is a reflector, for example, a wall.

  The processor 14 is included in the speaker system 1 having a plurality of speakers each having a certain directivity. In the present embodiment, the processor 14 includes a control unit 141, a measurement signal generation unit 142, a reflected sound information acquisition unit 143, a coefficient calculation unit 144, and a correction unit 145, as shown in FIG.

  The control unit 141 controls the input signal switching unit 15, the measurement signal generation unit 142, and the reflected sound information acquisition unit 143. The control unit 141 controls the input signal switching unit 15 so that a signal input to the amplifier 13 is a signal (music signal side) output by the correction unit 145 such as a music signal and a measurement signal generation unit such as a measurement signal. Switching is performed with the signal output from 142 (measurement signal side). The control unit 141 controls the measurement signal generation unit 142 to generate a signal for measuring the reflected sound characteristic of the speaker 12. The control unit 141 also controls the reflected sound information acquisition unit 143 to acquire the reflected sound information measured by the measurement microphone 16.

  The measurement signal generation unit 142 is controlled by the control unit 141 to generate a measurement signal for measuring the reflected sound characteristic of the speaker 12, and output the generated measurement signal to the input signal switching unit 15.

  The reflected sound information acquisition unit 143 uses the measurement microphone 16 to acquire reflected sound information regarding the influence of the sound reproduced from the speaker 12 reflected by the object. More specifically, the reflected sound information acquisition unit 143 is controlled by the control unit 141 and acquires the reflected sound information measured by the measurement microphone 16. The reflected sound information includes primary reflected sound information of each of the plurality of speakers (speakers 12a to 12d) that form the speaker 12.

  The coefficient calculation unit 144, based on the reflected sound information acquired by the reflected sound information acquisition unit 143, a correction coefficient that is a coefficient for correcting the acoustic characteristics of each of the plurality of speakers (speakers 12a to 12d) that form the speaker 12. calculate. More specifically, the coefficient calculation unit 144 determines a plurality of the plurality of speakers (speakers 12a to 12d) included in the reflected sound information acquired by the reflected sound information acquisition unit 143 based on the primary reflected sound information. A room shape, which is a room shape in which speakers (speakers 12a to 12d) are arranged and which is a room partitioned by a wall, and a speaker position which is a position of a plurality of speakers in the room shape are estimated. Then, the coefficient calculation unit 144 calculates a correction coefficient for each of the plurality of speakers (speakers 12a to 12d) from the estimated room shape and the speaker position.

  The correction unit 145 corrects the acoustic characteristics of each of the plurality of speakers (speakers 12a to 12d) that form the speaker 12 using the correction coefficient calculated by the coefficient calculation unit 144. Here, the acoustic characteristics of the plurality of speakers include at least one of the phase, sound level, and frequency characteristics of the plurality of speakers.

  In the present embodiment, the correction unit 145 includes an acoustic characteristic correction unit 145a, an acoustic characteristic correction unit 145b, an acoustic characteristic correction unit 145c, and an acoustic characteristic correction unit 145d. The acoustic characteristic correction unit 145a is connected to the amplifier 13a via the input signal switching unit 15, corrects the signal input to the input unit 11, and outputs the corrected signal to the amplifier 13a. The acoustic characteristic correction unit 145b is connected to the amplifier 13b via the input signal switching unit 15, corrects the signal input to the input unit 11 and outputs the signal to the amplifier 13b. The acoustic characteristic correction unit 145c is connected to the amplifier 13c via the input signal switching unit 15, corrects the signal input to the input unit 11 and outputs the corrected signal to the amplifier 13c. The acoustic characteristic correction unit 145d is connected to the amplifier 13d via the input signal switching unit 15, corrects the signal input to the input unit 11 and outputs the corrected signal to the amplifier 13d.

  The input signal switching unit 15 is controlled by the processor 14 and switches a signal input to the amplifier 13 between a signal (for example, a music signal) output by the correction unit 145 and a measurement signal output by the measurement signal generation unit 142. In the present embodiment, when the input signal switching unit 15 switches the signal input to the amplifier 13 to the measurement signal output by the measurement signal generation unit 142, the measurement signal output by the measurement signal generation unit 142 is further measured. The signal is transmitted to one of the amplifiers 13a to 13d.

[Signal Processing Method of Speaker System 1]
A signal processing method of the speaker system 1 configured as described above will be specifically described with reference to the drawings.

  FIG. 3 is a diagram showing an example of the positional relationship between the speaker 12 and the wall according to the present embodiment. FIG. 4 is a flowchart showing a signal processing method of speaker system 1 according to the present embodiment.

  As shown in FIG. 3, the speaker 12 includes a speaker 12a near the wall 2a of the room 2 and a position facing the wall 2a, a speaker 12d near the wall 2d and a position facing the wall 2d, and an opposite side of the speaker 12d (wall It is assumed that the speaker 12b is arranged at a position facing the wall 2b) and the speaker 12c is arranged at a side opposite to the speaker 12a (a position facing the wall 2c). The measurement microphone 16 is attached to the body of the speaker 12. It is provided at the same position as the speaker 12. A signal processing method of the speaker system 1 in this case will be described with reference to FIG.

  As shown in FIG. 4, first, when measuring the reflected sound characteristics of the speaker 12 (Yes in S11), the processor 14 of the speaker system 1 controls the input signal switching unit 15 to switch to the measurement signal side (S12). . Specifically, the processor 14 causes the input signal switching unit 15 to switch the signal input to the amplifier 13 from the signal of the correction unit 145 to the measurement signal of the measurement signal generation unit 142. When the reflected sound characteristic of the speaker 12 is measured, for example, it is at the time of initial setting after the speaker 12 is arranged, but the present invention is not limited to this. It may be any time when the listener who listens to the reproduced sound such as music using the speaker 12 wants to reduce the influence of the reflected sound on the acoustic characteristics.

  Next, the processor 14 causes the measurement signal generation unit 142 to generate a measurement signal for measuring the reflected sound characteristic (S13), and reproduces it by one of the plurality of speakers (speakers 12a to 12d) (S14). More specifically, the processor 14 causes the measurement signal generation unit 142 to generate a measurement signal, and the generated measurement signal is input to the input signal switching unit 15 to one of the amplifiers 13a to 13d and the amplifiers 13a to 13d. Let one communicate. The transmitted measurement signal is amplified by the one of the amplifiers 13a to 13d and reproduced by one of the speakers 12a to 12d corresponding to the one. The one of the amplifiers 13a to 13d is selected in ascending order from a to d.

  Next, the processor 14 causes the reflected sound information acquisition unit 143 to capture the measurement data (S15). More specifically, the signal reproduced by one of the speakers 12a-12d is measured by the measurement microphone 16 provided in the main body of the speaker 12 and acquired by the reflected sound information acquisition unit 143 as measurement data.

  Next, the processor 14 determines whether the measurement data captured by the reflected sound information acquisition unit 143 is the d-th speaker (speaker 12d) of the plurality of speakers, that is, the speakers 12a to 12d (S16). If it is not the d-th (No in S16), the process returns to S13 to continue the measurement. On the other hand, if it is d-th (Yes in S16), the process proceeds to the next S17.

  Next, the processor 14 causes the reflected sound information acquisition unit 143 to extract the reflected sound information of the plurality of speakers (speakers 12a to 12d) from the acquired measurement data (S17), and the coefficient calculation unit 144 causes the reflected sound information of the speaker 12 to be detected. The position and the shape of the room 2 are estimated (S18).

  Here, a method for estimating the position of the speaker 12 and the shape of the room 2 will be specifically described.

  5A to 5C are diagrams for explaining a method of estimating the position of speaker 12 and the shape of room 2 according to the present embodiment. FIG. 6 is a diagram for explaining an estimation method when the speaker 12 is not arranged in parallel with the walls 2a to 2d. The same elements as those in FIG. 3 and the like are designated by the same reference numerals, and detailed description thereof is omitted.

  In FIG. 5A, the paths of the primary reflected sound r1a and the secondary reflected sound r2a of the measurement signal reproduced by the speaker 12a to the measurement microphone 16 and the measurement microphone 16 and the walls 2a, 2b, 2c, and 2d. Distances La, Lb, Lc, Ld are shown. FIG. 5B is a diagram showing an example of reflected sound information of the time response waveform extracted from the measurement data of the measurement signal reproduced by the speaker 12a. FIG. 5C is a diagram showing an example of reflected sound information of the time response waveform extracted from the measurement data of the measurement signal reproduced by each of the speakers 12a to 12d.

  As shown in FIG. 5A, since the wall 2a is in front of the speaker 12a, the measurement signal reproduced by the speaker 12a is reflected by the wall 2a and reaches the measurement microphone 16. The magnitude of the sound reflected from the speaker 12a at the measurement microphone 16 is a time response waveform that is attenuated by the distance between the speaker 12a and the wall 2a, the distance between the wall 2a and the measurement microphone 16 and the reflection coefficient at the wall 2a. From the polar pattern of the speaker 12a shown in FIG. 2A, the speaker 12a has a directivity of 90 degrees. For this reason, the sound pressure level sharply decreases at angles deviating from the plus and minus 45 degrees in the front direction of the speaker 12a. Therefore, the position of the speaker 12a and the distance between the walls 2a, 2b, 2c, and 2d may be considered by using the dominant reflected sound (primary reflected sound) at a sound pressure level of about 90 degrees. .

  The processor 14 can estimate the position of the speaker 12a and the distance to the walls 2a, 2b, 2c, and 2d from the time response waveform as shown in FIG. 5B.

  More specifically, as shown in FIGS. 5A and 5B, the distance La from the speaker 12a to the wall 2a can be represented by (c × r1a × t) / 2. Here, c is the speed of sound (m / sec). That is, the distance from the primary reflected sound of the speaker 12a to the wall 2a can be estimated.

  Then, the distances Lb to Ld can be estimated from the time response waveform as shown in FIG. 5C by repeating the same processing using the measurement signals reproduced by the speakers 12b to 12d.

  Then, the horizontal distance of the room 2 can be estimated by adding the distance Lb and the distance Ld, and the vertical distance of the room 2 can be estimated by adding the distance La and the distance Lc. Can be estimated. Further, it can be estimated that the position of the speaker 12 is at a distance La from the wall 2a, a distance Lb from the wall 2b, a distance Lc from the wall 2c, and a distance Ld from the wall 2d.

  5A to 5C, the estimation method when the speaker 12 and the wall are arranged in parallel has been described, but the estimation method is not limited to this. As shown in FIG. 6, the estimation method can be similarly performed when the speaker 12 and the wall are not arranged in parallel. Even if the speaker 12 is not arranged in parallel with the walls 2a to 2d, since the speakers 12a to 12d constituting the speaker 12 each have a directivity angle of 90 degrees, the shortest distance from the walls 2a to 2d. The shape of the room 2 can be estimated by using the reflected sound (first-order reflected sound) returned by the same estimation method as in FIGS. 5A to 5C.

  Hereinafter, returning to FIG. 4, a signal processing method of the speaker system 1 will be described.

  Next, the processor 14 causes the coefficient calculation unit 144 to calculate the correction coefficient (S19), and causes the correction unit 145 to set the correction coefficient (S20). Then, the processor 14 causes the input signal switching unit 15 to switch the signal input to the amplifier 13 to the music signal side (S21).

  More specifically, the processor 14 causes the coefficient calculation unit 144 to calculate the correction coefficient of each of the speakers 12a to 12d that configure the speaker 12 from the estimated shape of the room 2 and the position of the speaker 12 to determine the acoustic characteristics. A correction coefficient is set for each of the correction units 145a to 145d. Then, the processor 14 controls the input signal switching unit 15 to switch the input signal to the signal side (music signal side) output by the correction unit 145.

  Here, a method of calculating the correction coefficient will be specifically described. FIG. 7 is a diagram showing a time response before correction at the position of the measurement microphone 16 according to the first embodiment. Note that (a) to (d) of FIG. 7 are the same as (a) to (d) of FIG. 5C, and a description thereof will be omitted. FIG. 8 is a diagram showing an example of the correction coefficient according to the first embodiment. FIG. 9 is a diagram showing a corrected time response at the position of the measurement microphone 16 according to the first embodiment.

  The coefficient calculation unit 144, for example, from the reflected sound information of each of the speakers 12a to 12d as illustrated in FIG. 5C, which is extracted by the reflected sound information acquisition unit 143, of the measurement microphone 16 illustrated in (e) of FIG. Estimate the time response before correction at position. Here, in FIGS. 7A and 7C, the level of the primary reflected sound is high. That is, in the speaker 12a and the speaker 12, the influence of the reflected sound from the wall 2a and the wall 2d is large. Therefore, in order to reduce this effect, the coefficient calculation unit 144 sets the correction coefficient of the speaker 12a to 0.1 times the normal coefficient and sets the correction coefficient of the speaker 12c to the normal coefficient, as shown in FIG. 0.2 times, and the correction coefficients of the other speakers 12b and 12d are made the same (1 times) as the normal coefficients. In this way, the coefficient calculation unit 144 reduces the input levels to the speakers 12a and 12c to eliminate the influence of the reflected sound and corrects the input levels to the other speakers 12b and 12 as they are. Calculate the coefficient.

  By setting the respective correction coefficients in the acoustic characteristic correction units 145a to 145d, the time response as shown in FIG. 9 can be obtained at the position of the measurement microphone 16, so that the influence of the reflected sound can be reduced. it can. That is, from the time response shown in (e) of FIG. 9, it can be seen that the reflected sound is small at the position of the measurement microphone 16, so there is almost no effect of the reflected sound from the walls 2a to 2d, and the speaker 12 It can be seen that the direct sound of is dominant and can be heard with good acoustic characteristics.

  In this way, the speaker 12 can reduce the influence of reflected sound while maintaining a wide directivity, and can obtain good acoustic characteristics.

  The method for calculating the correction coefficient is not limited to the method for calculating the input level correction coefficient, and the frequency characteristic correction coefficient may be calculated. This will be described below.

  FIG. 10 is an example of a detailed flowchart of S19 shown in FIG. 11A and 11B are diagrams for explaining a method of calculating the correction coefficient of the frequency characteristic.

  In S19, the coefficient calculation unit 144 first estimates the frequency characteristic of each speaker at the position of the measurement microphone 16 (S191). More specifically, the coefficient calculation unit 144 estimates the frequency characteristic shown in FIG. 11A from the reflected sound information of the speaker 12a as shown in FIG. 5C extracted by the reflected sound information acquisition unit 143, for example. In the present embodiment, as described above, it is estimated that a large dip will occur at the frequency of a certain cycle. This is because the measurement sound reproduced by the speaker 12a is reflected by the wall 2a.

  Next, the coefficient calculation unit 144 calculates the correction coefficient so that the characteristic of the frequency having the peak or the dip becomes close to flat (S192). More specifically, for example, in the frequency characteristic shown in FIG. 11A, the coefficient calculation unit 144 calculates a correction coefficient for the frequency characteristic that lowers the peak level and raises the dip level as shown in FIG. 11B.

[Effect]
As described above, according to the signal processing method and the speaker system 1 of the present embodiment, it is possible to reduce the influence of reflected sound on the acoustic characteristics.

  More specifically, according to the signal processing method and the speaker system 1 of the present embodiment, among the plurality of speakers (speakers 12a to 12d) constituting the speaker 12, the speaker whose reflected sound dominantly reaches the listener. The influence of the reflected sound on the acoustic characteristics can be reduced by increasing the correction coefficient of the acoustic characteristics. In this way, the signal processing method and the speaker system 1 of the present embodiment reduce the influence of the reflected sound from a reflective object such as a wall while maintaining a wide directivity, and the direct sound is dominant to the listener. Since it can reach the listener, the listener can listen to the sound with good acoustic characteristics.

(Modification)
In the first embodiment, the signal processing method and the like capable of reducing the influence of the reflected sound from the reflective object such as the wall so that the direct sound reaches the listener predominantly, the present invention is not limited to this. . The influence of the reflected sound from the wall or other reflective object may be reduced by making the sound reflected from the wall or other reflective object reach the listener as a sound. Hereinafter, this case will be described focusing on the points different from the first embodiment.

[Structure of Speaker System 1]
The speaker system 1 of the present modified example is different from the speaker system 1 according to the first embodiment shown in FIG. 1, for example, in the configuration of the coefficient calculation unit 144a.

  FIG. 12 is a diagram showing an example of a functional configuration of the coefficient calculation unit 144a according to the modified example of the present embodiment.

  The coefficient calculation unit 144a uses a correction coefficient that is a coefficient for correcting the acoustic characteristics of each of the plurality of speakers (speakers 12a to 12d) that form the speaker 12, based on the reflected sound information acquired by the reflected sound information acquisition unit 143. calculate. As shown in FIG. 12, the coefficient calculation unit 144a includes an estimation processing unit 1441, a coefficient calculation processing unit 1442, and a sound addition processing unit 1443.

  The estimation processing unit 1441 has a room shape in which a plurality of speakers are arranged and is partitioned by a wall based on the primary reflected sound information of each of the plurality of speakers included in the reflected sound information acquired by the reflected sound information acquisition unit 143. A room shape that is the shape of the obtained room 2 and speaker positions that are positions of a plurality of speakers in the room shape are estimated. The estimation processing unit 1441 further estimates the listening position in the room shape from the estimated room shape and speaker position, and reproduces from each of the plurality of speakers (speakers 12a to 12d) configuring the speaker 12 at the listening position. The response time given.

  The coefficient calculation processing unit 1442 calculates a correction coefficient for each of the plurality of speakers from the estimated room shape and speaker position.

  The reverberation addition processing unit 1443 uses the room shape, the speaker position, the listening position, and the response time estimated by the estimation processing unit 1441 to select the room among the plurality of speakers (speakers 12a to 12d) that form the speaker 12. By controlling the delay time and the sound level of the speaker facing the wall of No. 2, the reverberation at the listening position of the sound reproduced from the plurality of speakers (speakers 12a to 12d) is added. In the present modification, the reverberation addition processing unit 1443 controls the acoustic characteristic correction unit 145a, the acoustic characteristic correction unit 145b, the acoustic characteristic correction unit 145c, and the acoustic characteristic correction unit 145d, so that a plurality of speakers (constituting the speaker 12 ( The delay time and the sound level of the speaker facing the wall of the room 2 among the speakers 12a to 12d) are controlled.

  Note that not only the case where both the reverberation addition process and the process of calculating the correction coefficient and applying it to the correction unit 145 are performed, but only the reverberation addition process may be performed.

[Modified Signal Processing Method]
A signal processing method of the speaker system 1 of the modified example configured as described above will be described.

  FIG. 13 is a flowchart showing a signal processing method of speaker system 1 according to the modification of the present embodiment. The same elements as those in FIG. 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

  In S18, the processor 14 first causes the coefficient calculation unit 144 to estimate the position of the speaker 12 and the shape of the room 2 (S181). Subsequently, the processor 14 causes the coefficient calculation unit 144 to estimate the listening position in the shape of the room 2 from the estimated shape of the room 2 and the position of the speaker 12, and to configure a plurality of speakers that configure the speaker 12 in the listening position. The response time reproduced from each (speaker 12a to speaker 12d) is estimated.

  In S20A, first, the processor 14 causes the coefficient calculating unit 144 to set the correction coefficient calculated in S19 in the correcting unit 145 (S201). Subsequently, the processor 14 causes the coefficient calculation unit 144 to control the delay time and the level of the speaker facing the wall (S202).

  Here, the sound addition processing method will be specifically described.

  14 to 15B are diagrams for explaining the sound addition processing method according to the modification of the present embodiment. FIG. 14 shows an example of the relationship between the position of the speaker 12, the shape of the room 2, and the listening position 17. FIG. 15A shows an example of the time response waveform of the sound at the listening position 17 shown in FIG. FIG. 15B shows an example of the time response waveform of the sound at the listening position 17 after the sound addition processing.

  For example, as shown in FIG. 14, at the listening position 17, the primary reflected sound of the speaker 12a facing the wall 2a, the primary reflected sound of the speaker 12b facing the wall 2b, and the speaker 12d facing the wall 2d. The primary reflected sound of, and the direct sound of the speaker 12c arrive. In this case, for example, as shown in (a) to (d) of FIG. 15A, at the listening position 17, the sound of the time response waveform of each of the speakers 12a to 12d is heard, and as shown in (e) of FIG. 15A. , Hear the sound of the time response waveform of the speaker 12.

  Therefore, as shown in FIG. 15B, for example, the sound of the speakers 12a, 12b, and 12d facing the walls 2a, 2b, and 2d is delayed, and the input level is reduced to an appropriate level to add a sound. It is possible to create rich sounds that have been created.

  That is, in the example shown in FIGS. 14 and 15A, it can be estimated that the direct sound reaching the listening position 17 is only from the speaker 12c. Therefore, when the sounds of the speakers 12a, 12b, 12d are delayed, and the input level is made smaller than the primary reflected sound from the speakers 12a, 12b, 12d, and the primary reflected sound is emphasized, the sound of the primary reflected sound is emphasized. Is controlled to be large. As a result, the sound from the speaker 12 can be reverberated and the sound field feeling can be increased. The time for delaying the sound (delay time) needs to be changed according to the size of the room 2. For example, if the room 2 is 5 m × 5 m, the delay time may be about 50 ms to 100 ms, and the larger the size of the room 2, the longer the delay time.

[Effect]
As described above, according to the present modified example, from the position and the direction of each of the plurality of speakers constituting the speaker 12 estimated using the measurement microphone 16 located at the position of the speaker 12, the direction of the wall among the plurality of speakers is changed. By independently delaying the sound of the facing speaker and lowering the input level, a rich sound can be added at the listening position, for example.

  In this way, according to the signal processing method and the speaker system of the present modification, it is possible to reduce the influence of reflected sound on the acoustic characteristics.

(Embodiment 2)
In the first embodiment, the example in which the speaker 12 reproduces the entire frequency band of the music signal input to the input unit 11 and output from the processor 14 has been described. In the present embodiment, a case will be described where speaker 12 reproduces only a high frequency band (high frequency band) of the frequency band of the music signal output from processor 14.

[Structure of Speaker System 1B]
FIG. 16 is a diagram showing an example of the configuration of the speaker system 1B according to the second embodiment. The same elements as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

  The speaker system 1B according to the present embodiment differs from the speaker system 1 according to the first embodiment shown in FIG. 1 in that the processor 14A has a configuration including a band dividing unit 146, and further includes a low-frequency reproduction speaker 22. An amplifier 23 is added. Hereinafter, the differences from the first embodiment will be mainly described.

  The low-frequency reproduction speaker 22 is a speaker such as a woofer that is in charge of low-frequency reproduction, and is different from the speaker 12.

  The amplifier 23 is connected to the low-frequency reproduction speaker 22, amplifies the signal output from the processor 14A, and transmits the amplified signal to the low-frequency reproduction speaker 22.

  The band division unit 146 divides the frequency band of the signal input for reproduction by the speaker 12 and the low-frequency reproduction speaker 22 into at least a low-frequency band and a high-frequency band.

  The band dividing unit 146 outputs the divided high frequency band signal to the speaker 12, and outputs the divided low frequency band signal to the low frequency reproduction speaker 22.

[Signal Processing Method of Speaker System 1B]
A signal processing method of the speaker system 1B configured as above will be described.

  For example, when a music signal is input to the input unit 11, the band division unit 146 divides the input music signal into a high frequency band and a low frequency band. Here, the band dividing unit 146 may divide the low band and the high band near 3 kHz, for example.

  In this way, the music signal in the high frequency band is reproduced by the speaker 12 through the correction unit 145 and the amplifier 13. The music signal in the low frequency band passes through the amplifier 23 and is reproduced by the low frequency reproduction speaker 22.

[Effect]
As described above, according to the present embodiment, it is possible to realize the signal processing method and the speaker system 1B that can reduce the influence of the reflected sound on the acoustic characteristics.

  More specifically, the signal processing method and the speaker system 1B according to the present embodiment reduce the influence of the sound reflected from a reflective object such as a wall while maintaining a wide directivity, so that the listener can hear the high frequency band. Since the direct sound can be dominantly reached, the listener can hear with good acoustic characteristics.

(Modification)
A low-frequency characteristic correction unit may be added between the amplifier 23 and the band division unit 146.

  When a music signal in the low frequency band is reproduced by the low frequency reproduction speaker 22, the frequency characteristic of the low frequency reproduction speaker 22 near f0 changes depending on the location of the speaker 12 such as on the wall of the room 2 or in the middle of the room 2. This is because the balance between the low range and the high range will change. For example, when the speaker 12 is placed near the wall of the room 2, the frequency of the low-frequency reproduction speaker 22 near f0 becomes high.

  In this case, the coefficient calculation unit 144 further calculates a correction coefficient that is a coefficient for correcting the acoustic characteristic of the low-frequency reproduction speaker 22 based on the reflected sound information acquired by the reflected sound information acquisition unit 143, and It may be set in the characteristic correction unit.

  As described above, according to the speaker system of the present modification, even if the speaker system further includes the low-frequency reproduction speaker 22 and is configured by the 2-way speaker of the high frequency range and the low frequency range, the speaker 12 does not depend on the place where the speaker 12 is placed. A balance between the low range and the high range can be maintained. Thereby, the disturbance of the frequency characteristic due to the reflected sound is small, and it is possible to listen with a good sound at a wide listening position.

(Embodiment 3)
The first and second embodiments have described the configuration in which the speaker system estimates the position of the speaker 12 and the shape of the room 2 using the measurement microphone, but the present invention is not limited to this. The position of the speaker 12 and the shape of the room 2 may be input to the speaker system by the user (listener) of the speaker system. Hereinafter, this case will be described.

[Configuration of speaker system 1C]
FIG. 17 is a diagram showing an example of the configuration of the speaker system 1C according to the third embodiment. The same elements as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

  The speaker system 1C of the present embodiment is different from the speaker system 1 shown in FIG. 1 in the configuration of the processor 14C, and further, the input signal switching unit 15 and the measurement microphone 16 are deleted, and the input unit 31 and the display device. 32 and 32 are added. In the processor 14C of the present embodiment, the control unit 141, the measurement signal generation unit 142, and the reflected sound information acquisition unit 143 are deleted and the reflected sound estimation unit 147 is added to the processor 14 according to the first embodiment. ing. Hereinafter, the differences from the first embodiment will be mainly described.

  The display device 32 is, for example, a touch panel display, and displays the room shape, the position of the speaker, and the like as an image on the display screen. The shape of the room and the position of the speaker displayed on the display screen can be changed by the user (listener). The display device 32 is connected to the input unit 31, and changes in the shape of the room and the position of the speaker displayed on the display screen are output to the input unit 31.

  The input unit 31 receives inputs of a distance between each of the plurality of speakers (speakers 12a to 12d) forming the speaker 12 and an object in the sound emission direction of each of the plurality of speakers, and a listening position. Here, the object is a reflector, for example, a wall. In the present embodiment, the user (listener) changes the position and orientation of the speaker displayed on the display screen of the display device 32, and designates the listening position. Inputs of the distance to and the listening position are received. The user (listener) directly inputs the position of each of the plurality of speakers (speakers 12a to 12d) configuring the speaker 12, the distance between each of the plurality of speakers (speakers 12a to 12d) and the wall, to the input unit 31. The distance from each of the plurality of speakers (speakers 12a to 12d) to the listening position, the distance between the wall and the listening position, the reflection coefficient of the wall, and the like may be input.

  The reflected sound estimation unit 147 receives the sound reproduced from the plurality of speakers (speakers 12a to 12d) forming the speaker 12 as reflected sound information from the distance between the speaker and the wall received at the input unit 31, and the listening position. An estimated reflected sound, which is the sound when reflected by, is calculated. More specifically, the reflected sound estimation unit 147 determines the direct sound from each of the plurality of speakers (speakers 12a to 12d) that form the speaker 12 and the reflected sound from the wall based on the information received by the input unit 31. The time and the loudness are calculated as the estimated reflected sound.

  Then, the coefficient calculation unit 144 is a coefficient that corrects the acoustic characteristics of each of the plurality of speakers (speakers 12a to 12d) that configure the speaker 12 based on the estimated reflected sound calculated by the reflected sound estimation unit 147. Calculate the coefficient.

[Signal Processing Method of Speaker System 1C]
A signal processing method of the speaker system 1C configured as above will be described.

  FIG. 18 is a flowchart showing a signal processing method of speaker system 1C according to the present embodiment. FIG. 19 is a diagram showing an example of a display screen of the display device 32 according to the present embodiment.

  First, the display device 32 displays the shape of the room, the position of the speaker, and the like as an image on the display screen (S31). In the example shown in FIG. 19, the display device 32 displays the shape of the room 322 such as a rectangle and the position of the speaker 323 on the display screen 321. Here, the room 322 corresponds to the room 2 in Embodiments 1 and 2, but is a room virtually displayed on the display screen 321. The speaker 323 corresponds to the speaker 12 of the first and second embodiments, but is a speaker virtually displayed on the display screen 321.

  Next, the user inputs the position of the speaker 12, the direction of the speaker 12, and the listening position (S32). In the example shown in FIG. 19, the user changes the position of the speaker 323 displayed on the display screen 321 in the room 322 so as to match the position of the speaker 12 in the actual room 2. The user also specifies the listening position 324 in the room 322 displayed on the display screen 321 so as to match the actual listening position in the room 2. The user may further input the reflection coefficient of the wall of the room 322 into the input unit 31.

  Next, the processor 14C of the speaker system 1C causes the coefficient calculation unit 144 to calculate the correction coefficient at the listening position input in S32 (S33), and causes the correction unit 145 to set the calculated correction coefficient (S34).

  More specifically, first, the processor 14C of the speaker system 1C reproduces from the plurality of speakers (speakers 12a to 12d) forming the speaker 323 on the basis of the information input in S32 in the reflected sound estimation unit 147. An estimated reflected sound that is a sound when the sound is reflected by the object is calculated. Next, the processor 14C of the speaker system 1C causes the coefficient calculation unit 144 to use the estimated reflected sound calculated by the reflected sound estimation unit 147 and the listening position 324 input in S32, at the listening position 324 input in S32. The correction coefficient is calculated. The coefficient calculation unit 144 includes a direct sound of a plurality of speakers (speakers 12 a to 12 d) constituting the speaker 323 at the listening position 324, which is calculated as an estimated reflected sound by the reflected sound estimation unit 147, and a reflection from a wall of the room 322. The correction coefficient set in the correction unit 145 is calculated in consideration of the influence of the reflected sound at the listening position 324 based on the time and the volume of the sound. Then, the coefficient calculation unit 144 sets the calculated correction coefficient in the correction unit 145.

[Effect]
As described above, according to the present embodiment, it is possible to realize a signal processing method and a speaker system that can reduce the influence of reflected sound on the acoustic characteristics.

  More specifically, the signal processing method and the speaker system of the present embodiment reduce the influence of reflected sound from a reflective object such as a wall while maintaining a wide directivity, and the direct sound is dominant to the listener. Since it can reach the listener, the listener can listen to the sound with good acoustic characteristics.

  The signal processing method and the speaker system according to one or more aspects of the present invention have been described above based on the embodiment, but the present invention is not limited to this embodiment. As long as it does not depart from the gist of the present invention, various modifications conceived by those skilled in the art may be applied to the present embodiment, or a configuration constructed by combining components in different embodiments may be one or more of the present invention. It may be included in the range of the aspect. For example, the following cases are also included in the present invention.

  (1) Each of the above devices is specifically a computer system including a microprocessor, a ROM, a RAM, a hard disk unit, a display unit, a keyboard, a mouse, and the like. A computer program is stored in the RAM or the hard disk unit. Each device achieves its function by the microprocessor operating according to the computer program. Here, the computer program is configured by combining a plurality of instruction codes indicating instructions to the computer in order to achieve a predetermined function.

  (2) Some or all of the constituent elements of each of the above devices may be configured by one system LSI (Large Scale Integration). The system LSI is a super-multifunctional LSI manufactured by integrating a plurality of components on a single chip, and specifically, is a computer system including a microprocessor, ROM, RAM and the like. . A computer program is stored in the RAM. The system LSI achieves its function by the microprocessor operating according to the computer program.

  (3) Part or all of the constituent elements of each of the above devices may be configured with an IC card that can be attached to and detached from each device or a single module. The IC card or the module is a computer system including a microprocessor, ROM, RAM and the like. The IC card or the module may include the super multifunctional LSI described above. When the microprocessor operates according to the computer program, the IC card or the module achieves its function. This IC card or this module may be tamper resistant.

  (4) The present invention may be methods shown by the above. Further, it may be a computer program that realizes these methods by a computer, or may be a digital signal including the computer program.

  Further, the present invention provides a computer-readable recording medium such as the computer program or the digital signal, for example, a flexible disk, a hard disk, a CD-ROM, a MO, a DVD, a DVD-ROM, a DVD-RAM, a BD (Blu-ray). (Registered trademark) Disc), or may be recorded in a semiconductor memory or the like. Further, it may be the digital signal recorded on these recording media.

  Further, the present invention may be the computer program or the digital signal transmitted via an electric communication line, a wireless or wired communication line, a network typified by the Internet, a data broadcast, or the like.

  Further, the present invention may be a computer system including a microprocessor and a memory, wherein the memory stores the computer program and the microprocessor operates according to the computer program.

  In addition, by recording and transferring the program or the digital signal in the recording medium, or by transferring the program or the digital signal via the network or the like, it is carried out by another independent computer system. You may.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a signal processing method and a speaker system, and is particularly the same for many people in a small space such as an audio device, a classroom or a coffee shop, which reproduces music with good acoustic characteristics in a wide range in a music reproduction space. INDUSTRIAL APPLICABILITY The present invention can be used for a signal processing method and a speaker system used for facility applications for reproducing music with acoustic characteristics.

1, 1B, 1C Speaker system 2, 322 Room 2a, 2b, 2c, 2d, 93 Wall 11, 31 Input section 12, 12a, 12b, 12c, 12d, 92, 323 Speaker 13, 13a, 13b, 13c, 13d, 23 amplifier 14, 14A, 14C processor 15 input signal switching unit 16 measurement microphone 17, 94, 324 listening position 22 low-range reproduction speaker 32 display device 141 control unit 142 measurement signal generation unit 143 reflected sound information acquisition unit 144, 144a coefficient Calculation unit 145 Correction unit 145a, 145b, 145c, 145d Acoustic characteristic correction unit 146 Band division unit 147 Reflected sound estimation unit 321 Display screen 1441 Estimation processing unit 1442 Coefficient calculation processing unit 1443 Reverberation addition processing unit

Claims (6)

A signal processing method performed by a processor included in a speaker system having a plurality of speakers each having a certain directivity,
Using a measurement microphone, an acquisition step of acquiring reflected sound information related to the effect when the sound reproduced from the plurality of speakers is reflected by an object,
A coefficient calculation step of calculating a correction coefficient which is a coefficient for correcting the acoustic characteristics of the plurality of speakers based on the reflected sound information acquired in the acquisition step;
Look including a correction step of correcting the acoustic characteristics of the plurality of speakers using the correction coefficient calculated in the coefficient calculating step,
The measurement microphone is arranged at the same position as the plurality of speakers,
In the coefficient calculation step,
Based on the primary reflected sound information of each of the plurality of speakers included in the reflected sound information acquired in the acquisition step, a room shape in which the plurality of speakers are arranged and a room shape partitioned by a wall. A room shape and an estimation step of estimating speaker positions which are positions of the plurality of speakers in the room shape;
A correction coefficient calculation step of calculating a correction coefficient for each of the plurality of speakers from the room shape and the speaker position estimated in the estimation step,
Signal processing method. In the estimation step, further, from the estimated room shape and the speaker position, the listening position in the room shape is estimated, and the response time reproduced from the plurality of speakers at the listening position is estimated,
The signal processing method further comprises
Controlling the delay time and the sound level of the speaker facing the wall of the room among the plurality of speakers based on the room shape, the speaker position, the listening position, and the response time estimated in the estimating step. In addition, a sound addition step of adding the sound at the listening position of the sound reproduced from the plurality of speakers,
The signal processing method according to claim 1 . The speaker system further includes a low-frequency reproduction speaker different from the plurality of speakers,
The signal processing method further includes a band division step of dividing a frequency band of a signal input for reproduction by the plurality of speakers and the low-frequency reproduction speaker into at least a low-frequency band and a high-frequency band. Including,
In the band division step, the divided high frequency band signal is output to the plurality of speakers, the divided low frequency band signal is output to the low frequency reproduction speaker,
The signal processing method according to claim 1 or 2. In the acquisition step,
A receiving step of receiving an input of each of the plurality of speakers, a distance between the object in the sound emission direction of each of the plurality of speakers, and a listening position;
Reflected sound estimation that calculates an estimated reflected sound that is a sound when the sound reproduced from the plurality of speakers is reflected by the object as the reflected sound information from the distance and the listening position received in the receiving step. Including steps and,
The signal processing method according to claim 1. The acoustic characteristics of the plurality of speakers are
Including at least one of the phase, sound level and frequency characteristics of the plurality of speakers,
The signal processing method according to any one of claims 1-4. A speaker system having a plurality of speakers each having a certain directivity,
Using a measurement microphone, a reflected sound information acquisition unit that acquires reflected sound information related to the influence when the sound reproduced from the plurality of speakers is reflected by an object,
A coefficient calculation unit that calculates a correction coefficient that is a coefficient that corrects the acoustic characteristics of the plurality of speakers based on the reflected sound information acquired by the reflected sound information acquisition unit;
A correction unit that corrects the acoustic characteristics of the plurality of speakers using the correction coefficient calculated by the coefficient calculation unit;
The measurement microphone is arranged at the same position as the plurality of speakers,
In the coefficient calculation unit,
On the basis of the primary reflected sound information of each of the plurality of speakers included in the reflected sound information acquired by the reflected sound information acquisition unit, a room shape in which the plurality of speakers are arranged and which is partitioned by a wall A room shape that is a shape, and an estimation unit that estimates speaker positions that are positions of the plurality of speakers in the room shape;
A correction coefficient calculation unit that calculates a correction coefficient for each of the plurality of speakers from the room shape and the speaker position estimated by the estimation unit;
Speaker system.

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