JP4096960B2 - Speaker array device - Google Patents

Description

  The present invention relates to a speaker array device that outputs a plurality of sound beams and reproduces surround sound, and more particularly to a speaker array device that has a high degree of freedom in installation location and can easily set sound directivity. .

  Conventionally, a technique for controlling the directivity of sound signal propagation by forming a plurality of sound beams using a speaker array composed of a plurality of speakers arranged in a matrix (see, for example, Patent Document 1). ). By using this technology, it is not necessary to install a plurality of speakers around the user (listener) as in the conventional surround system, and a plurality of sound beams are output from a single panel speaker array. Surround sound can be played.

  FIG. 10 is a top perspective view of a listening room in which the speaker array device disclosed in Patent Document 1 is installed, and shows an example in which a 5.1 channel surround system is realized by the speaker array device. In the following description, in the 5.1 channel surround system, the front left channel is L (Left) ch, the front right channel is R (Right) ch, the center channel is C (Center) ch, and the rear left The channel is called SL (Surround Left) ch, the rear right channel is called SR (Surround Right) ch, and the subwoofer is called LFE (Low Frequency Effects) ch.

  A speaker array apparatus 213 shown in FIG. 10 includes a plurality of speaker units arranged in a predetermined arrangement on a baffle plate, and adjusts the timing for outputting surround sound from each speaker unit for each channel and radiates it in a beam shape. Then, delay control is performed so that the sound beam is focused at an arbitrary point in space. Then, by reflecting the sound of each channel to the ceiling or wall, a sound source is created in the wall direction and a multi-channel sound field is reproduced.

  As shown in FIG. 10, the speaker array device 213 disposed in the listening room 220 directly outputs the same sound as the center speaker (C) and the subwoofer (LFE) for low sound reinforcement to the user U. In addition, the speaker array device 213 reflects the sound beam on the left and right walls 221 and 222 of the listening room 220 to create a virtual Rch speaker 214 and a virtual Lch speaker 215. Further, the speaker array device 213 reflects the sound beams on the left and right walls 221 and 222 and the rear wall 223 of the listening room 220 to create virtual SRch speakers 216 and virtual SLch speakers 217 on the left and right sides of the user U. As described above, in the surround system using the speaker array, the sound signal of each channel is delayed and beamed, and the beamed sound is reflected on the wall to create a plurality of sound sources, thereby creating a plurality of sound sources around the user U. A surround feeling as if a speaker was installed can be obtained.

Japanese translation of PCT publication No. 2003-510924

  Conventionally, when installing a speaker array device, the speaker array device is provided with the width, depth, and height of the listening room as information on the listening position of the user and shape information of the installation environment. The directivity of the voice was automatically calculated and set. In addition, when such a setting function is not provided in the speaker array device, or when the preconditions for automatic calculation and the room environment are greatly different, an expert listens to the reproduction sound of the speaker array device at the listening position, Adjustments were made while manually changing the sound directivity of each channel.

  However, when the speaker array device automatically sets the sound directivity of each channel based on the shape and size information of the room input by the user, the shape of the listening room in which the speaker array device is installed and the speaker array device There was a problem that the installation location was limited. In other words, the listening room in which the speaker array device is installed has an ideal shape such as a rectangular parallelepiped or a cube as shown in FIG. Could not be requested. Therefore, in a listening room with a specially shaped listening room or large furniture, the sound directivity setting of the speaker array device cannot be set automatically, and manual adjustment may be necessary. It was.

  In addition, when setting the directivity of the sound of each channel manually, the sound beam adjustment often depends on the sense of the setter, so individual differences are likely to occur in the viewing environment, and the setting operation requires knowledge and knowledge. Familiarity is necessary. Therefore, the adjustment of the sound beam is performed by an expert as described above, and there is a problem that it is difficult for the user himself to adjust.

  The present invention has been made to solve the above-described problems, and provides a speaker array device that has a high degree of freedom in the installation location of the speaker array device and that allows the user to easily set the sound directivity. Objective.

The speaker array device of the present invention adds a delay time to each of a multi-channel audio signal input from the outside and a speaker array composed of a plurality of speaker units arranged in a matrix or a line. , Directivity control means for driving the speaker array so that sounds corresponding to the multi-channel sound signals are radiated with different directivities, and measurement signals from the speaker array when setting the directivity control means. A test sound beam corresponding to the sound sound, and a sound beam sweeping means for sweeping to gradually change the radiation angle of the test sound beam; and a test sound beam installed at a listening position in a room where the speaker array is installed. A microphone that collects the direct sound and reflected sound of the sound and the focal length of the test sound beam during the sweep The focal length setting means for setting the same value as the microphone distance from the speaker array to the microphone, and the relationship between the signal level of the sound collected by the microphone during the sweep and the radiation angle of the test sound beam as measurement data The storage means for storing, the signal peak of the measurement data stored in the storage means, and the radiation angle of the test sound beam when this signal peak is obtained, the radiation angle for outputting the multi-channel sound for each channel. And determining the directivity of the multi-channel sound for each channel from the radiation angle obtained by the angle detection unit, and setting the delay time corresponding to the directivity to the directivity control unit. And directivity setting means for setting each time.
In addition, one configuration example of the speaker array device of the present invention further includes microphone distance measuring means for measuring the microphone distance before sweeping the test sound beam.
Further, one configuration example of the speaker array apparatus of the present invention further includes measurement signal setting means for setting a frequency band of the measurement signal to a maximum frequency at which directivity can be controlled by the speaker array, and the test sound beam. Determining whether or not the microphone distance is longer than a predetermined limit distance before performing the sweep, and if the microphone distance is equal to or less than the limit distance, microphone distance determination means for prompting the user to correct the position of the microphone; It is what you have.

  According to the present invention, when the speaker array apparatus is installed indoors, a microphone is installed at the listening position of the user, and a test sound beam corresponding to the measurement signal is emitted from the speaker array, and the test sound beam is emitted. By sweeping the angle gradually and collecting the sound with the microphone at this time, the sound output directly from the speaker array to the microphone or the sound reflected from the room wall toward the microphone It can be detected as a level peak. As a result, it is possible to easily detect in a short time whether a multi-channel sound can be optimally reproduced when each sound is output from the array speaker at what radiation angle. As a result, according to the present invention, regardless of the shape of the room in which the speaker array device is installed or the arrangement of furniture, the user can easily and appropriately set the directivity control means of the speaker array device. Further, in the present invention, by setting the focal length of the test sound beam to the same value as the microphone distance from the speaker array to the microphone, the degree of separation between the direct sound and the reflected sound of the test sound beam can be increased. The S / N ratio of the sound can be improved, the peak detection of the reflected sound corresponding to the surround channel and the front channel can be facilitated, and the angle range in which the peak of the reflected sound can be detected can be widened. As a result, according to the present invention, it is possible to easily and accurately obtain the optimum radiation angle for outputting the sound of each channel.

  Further, in the present invention, the microphone distance is measured before the test audio beam is swept, thereby eliminating the need for the user to input the microphone distance.

  In the present invention, the frequency band of the measurement signal is set to the highest frequency at which directivity can be controlled by the speaker array, it is determined whether the microphone distance is longer than a predetermined limit distance, and the microphone distance is equal to or less than the limit distance. In this case, it is possible to avoid deterioration of the angular resolution of the reflected sound by prompting the user to correct the position of the microphone.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a speaker array apparatus according to an embodiment of the present invention, and FIG. 2 is a front view showing an arrangement example of speaker units on a baffle plate of the speaker array.
The speaker array device 1 according to the present embodiment includes a microphone 2, an A / D converter 3, a level measurement unit 4, a beam angle detection unit 5, a control unit 6, a measurement signal generation unit 7, and a beam control unit. 8, an amplifier 9, a speaker array 10, an operation unit 11, and a display unit 12. The level measurement unit 4 constitutes storage means, the beam angle detection unit 5 constitutes angle detection means, and the control unit 6 constitutes focal length setting means, directivity setting means, measurement signal setting means, and microphone distance determination means. The beam control unit 8 constitutes a directivity control unit, and the control unit 6, the measurement signal generation unit 7, and the beam control unit 8 constitute an audio beam sweep unit. The control unit 6, the measurement signal generation unit 7, and the beam The control unit 8, the amplifier 9, the speaker array 10, the microphone 2, the A / D converter 3, and the level measuring unit 4 constitute a microphone distance measuring unit. In addition, the part except the microphone 2 of the speaker array apparatus 1 shown in FIG. 1 is called the main body 1h.

The microphone 2 is an omnidirectional microphone and is connected to the A / D converter 3.
The A / D converter 3 converts the analog audio signal collected by the microphone 2 into a digital audio signal in the audio beam setting mode in which the beam control unit 8 is set by obtaining the sound radiation angle and path distance of each channel. And output to the level measuring unit 4.

The level measurement unit 4 stores measurement data collected by the microphone 2 in the sound beam setting mode.
The beam angle detection unit 5 reads the measurement data stored in the level measurement unit 4 after the sound collection in the sound beam setting mode is completed, detects the peak of the measurement data, and Cch, Lch, Rch, SLch, SRch The radiation angle at which the sound of each channel is output is detected, and the detection result is notified to the control unit 6.

The measurement signal generator 7 outputs a measurement signal to the beam controller 8 in the sound beam setting mode.
In the sound beam setting mode, the beam control unit 8 outputs a test sound beam corresponding to the measurement signal from the measurement signal generation unit 7 from the speaker array 10 while changing the radiation angle, and during normal listening after the setting is completed. Then, the directivity according to the setting is given to the sound of each channel and output from the speaker array 10.

  The speaker array 10 has a plurality of speaker units 101 arranged in a matrix or a line on a front baffle plate 100. In the example of FIG. 2, an example in which the speaker units 101 are arranged in a matrix is shown.

  Here, the principle of directivity control by the speaker array apparatus 1 will be described with reference to FIG. A large number of speaker units 101-1 to 101-n are arranged in a line, an arc whose distance from the focal point P is L is Z, and a straight line connecting the focal point P and each of the speaker units 101-1 to 101-n is a straight line. Suppose that virtual speaker units 102-1 to 102-n as shown by broken lines in FIG. 3 are arranged at intersections where these extended straight lines intersect with the arc Z. Since the distances from these virtual speaker units 102-1 to 102-n to the focal point P are all L, the sound radiated from each of the speaker units 102-1 to 102-n reaches the focal point P at the same time.

  In order to simultaneously allow the sound radiated from the actual speaker unit 101-i (i = 1, 2,... N) to reach the focal point P, the speaker unit 101-i and the corresponding virtual speaker unit 102. What is necessary is just to add the delay (time difference) according to the distance between -i to the sound output from the speaker unit 101-i. That is, when viewed from the focal point P, control is performed as if virtual speaker units 102-1 to 102-n are arranged on the arc Z. As a result, at the focal point P, the phases of the outputs of the speaker units 101-1 to 101-n are aligned and a sound pressure peak is created. As a result, a sound pressure distribution having a directivity that emits an audio beam toward the focal point P can be obtained. In addition, by arranging the speakers in a matrix rather than a line, a sound beam having a three-dimensional directivity can be output.

  FIG. 4 is a diagram schematically illustrating the processing of the beam control unit 8 for the audio signal. The delay unit 80-L generates (n) Lch audio signals corresponding to the number of speaker units, each of which adds a delay time to the input Lch audio signal, and the delay unit 80-R receives the input Rch audio signal. N Rch audio signals each having a delay time added to the signal are generated, and the delay unit 80-C generates n Cch audio signals each having a delay time added to the input Cch audio signal. The delay unit 80-SL generates n SLch audio signals obtained by adding a delay time to the input SLch audio signal, and the delay unit 80-SR outputs the input SRch audio signal. Each of the n SRch audio signals to which the delay time is added is generated. Delay times added by the delay units 80-L, 80-R, 80-C, 80-SL, and 80-SR are individually set by the control unit 6.

Then, the adder 81-1 includes Lch, Rch, Cch, SLch, SRch for the speaker unit 101-1 output from the delay units 80-L, 80-R, 80-C, 80-SL, 80-SR. Are added to generate the audio signal AO-1, and the adder 81-2 adds the Lch, Rch, Cch, SLch, and SRch audio signals for the speaker unit 101-2 to generate the audio signal. AO-2 is generated, and the adder 81-n adds the audio signals of Lch, Rch, Cch, SLch, SRch for the speaker unit 101-n to generate an audio signal AO-n.
The amplifiers 9-1 to 9-n amplify the audio signals AO-1 to AO-n output from the beam control unit 8, respectively, and drive the speaker units 101-1 to 101-n.

For example, the operation unit 11 receives various setting inputs from the user when the speaker array device 1 is installed, and passes the input information to the control unit 6.
The display unit 12 displays the content transmitted to the user based on the control signal output from the control unit 6.

  The control unit 6 controls the entire speaker array apparatus. In the sound beam setting mode, the control unit 6 causes the measurement signal generation unit 7 and the beam control unit 8 to sweep the test sound beam, and at the same time, obtains the measurement data at this time from the level measurement unit. 4, and the setting of the beam control unit 8 is performed based on the measurement data.

  Next, the operation of the speaker array device 1 of the present embodiment will be described. FIG. 5 is a flowchart showing the operation of the speaker array device 1 in the sound beam setting mode. First, the user U installs the speaker array 10 at a desired position in the listening room and installs the microphone 2 at the listening position.

  When the control unit 6 is instructed to execute the sound beam setting mode by the user, the control unit 6 measures the microphone distance from the speaker array 10 to the microphone 2 (listening position) (step S1). To measure the microphone distance, the control unit 6 controls the measurement signal generation unit 7 to output a pulse signal and noise for measuring the microphone distance, and outputs the sound corresponding to the pulse signal and noise from the speaker array 10. Let At this time, the beam controller 8 does not need to add a delay time to the pulse signal or noise. The sound output from the speaker array 10 is collected by the microphone 2 and recorded in the level measuring unit 4 as a digital signal through the A / D converter 3.

  The control unit 6 measures the elapsed time from when the pulse signal or noise is output from the measurement signal generation unit 7 to the beam control unit 8 until the level measurement unit 4 obtains the pulse signal or noise. The microphone distance is calculated based on (Step S2). Subsequently, the control unit 6 determines whether or not the microphone distance obtained in step S2 is longer than a predetermined limit distance (step S3). The reason for making such a determination will be described later. Although the microphone distance is measured in this embodiment, the user may input it.

  When it is determined in step S3 that the microphone distance is longer than the limit distance, the control unit 6 sweeps the test audio beam, and sets the focal length of the test audio beam before performing this sweep (step S4). Here, the sweep of the test sound beam will be described. FIG. 6 is a top perspective view of the listening room 20 in which the speaker array device 1 is installed, and is a diagram for explaining the test sound beam sweep operation of the present embodiment. As shown in FIG. 6A, the speaker array 10 is arranged so that the baffle plate of the speaker array 10 is parallel to the front wall 21 and faces the rear wall 23 at the center of the front wall 21 of the listening room 20. Install. Further, the microphone 2 is installed at the listening position of the user. At this time, the height of the microphone 2 is preferably adjusted to the position of the user's ear.

  The controller 6 of the speaker array device 1 causes the measurement signal generator 7 to output a measurement signal to the beam controller 8 and causes the speaker array 10 to output a test sound beam 30 corresponding to the measurement signal. At this time, in response to an instruction from the control unit 6, the beam control unit 8 changes the baffle plate from one direction (hereinafter referred to as 0 degree direction) parallel to the baffle plate of the speaker array 10 as shown in FIG. A sweep is performed to gradually change the radiation angle of the test sound beam 30 to the other parallel direction (hereinafter referred to as a 180-degree direction). This sweep can be realized by setting the delay time of the delay unit of the beam control unit 8 to which the measurement signal is input from the control unit 6 and gradually changing the focal position of the test audio beam 30. Here, since only the measurement signal of one channel is input to the beam control unit 8, measurement is performed on any one of the delay units 80-L, 80-R, 80-C, 80-SL, and 80-SR. What is necessary is just to input a signal.

  As described above, when the test audio beam is swept, the test audio beam is applied to the left wall 22, the rear wall 23, and the right wall 24 of the listening room 20 according to the radiation angle θ of the test audio beam output from the speaker array 10. Is reflected. At this time, the microphone 2 collects the direct sound of the test sound beam and the indirect sound reflected by each wall. The A / D converter 3 converts the analog audio signal collected by the microphone 2 into a digital audio signal, and the level measuring unit 4 stores this digital audio signal as measurement data together with the radiation angle θ.

  For example, as shown in FIG. 6B, when the radiation angle θ = θ1, the test sound beam 30a is reflected by the left wall 22 and the right wall 24 and then reaches the microphone 2, so that θ1 is an Lch sound beam. Is not suitable as an angle to output. When the radiation angle θ = θ2, the test sound beam 30b is reflected by the left wall 22 and then reaches the microphone 2. Therefore, θ2 is an appropriate angle for outputting the Lch sound beam. When the radiation angle θ = θ3, the test sound beam 30c is reflected by the left wall 22 and the rear wall 23 and then reaches the microphone 2. Therefore, θ3 is an appropriate angle for outputting the SLch sound beam. is there. Further, when the radiation angle θ = θ4, the test sound beam 30d directly reaches the microphone 2, so θ4 is an appropriate angle for outputting the Cch sound beam.

Thus, the optimum radiation angle for outputting the sound of each channel can be obtained by sweeping the test sound beam and analyzing the measurement data obtained by the sweep.
The process of step S4 is a process of setting the microphone distance obtained in step S2 as the focal distance of the test audio beam. The control unit 6 causes the measurement signal generation unit 7 and the beam control unit 8 to sweep the test audio beam described with reference to FIG. 6A (step S5), but from the speaker array 10 to the focus by the setting in step S4. The focal length is always fixed at a fixed microphone distance. The reason why the focal length is the same as the microphone distance will be described later.

  The measurement signal used for sweeping the test audio beam is preferably an audio signal that has no correlation and is limited to a frequency band in which directivity can be controlled by the speaker array device 1.

  After the sweep of the test audio beam is completed, the control unit 6 causes the beam angle detection unit 5 to perform a radiation angle detection process (step S6). 7A and 7B are diagrams for explaining the radiation angle detection process. FIG. 7A is a top perspective view showing the sweep operation of the test sound beam, and FIG. 7B is a level measurement by the sweep operation of the test sound beam. FIG. 6 is a diagram showing measurement data stored in a unit 4. In FIG. 7B, the horizontal axis represents the radiation angle of the test sound beam, and the vertical width represents the gain of sound data collected by the microphone 2.

  In order to easily detect a plurality of peaks from the measurement data shown in FIG. 7B, the threshold value Tha is set in advance to a level at which only a sound beam reflected up to two times can be detected. In step S6, the beam angle detection unit 5 analyzes the measurement data of the level measurement unit 4, and the radiation angle θa3 (of FIG. 7A) when the peak Pa3 having the highest level equal to or higher than the threshold Tha is obtained. The angle of the test sound beam 47) is defined as a radiation angle at which Cch sound is output. The reason why the angle θa3 is set as the radiation angle of the Cch sound is that the Cch sound is directly radiated to the listening position of the user. The beam angle detection unit 5 regards a peak having a pulse width equal to or less than a predetermined value as noise and excludes it even if the level is maximum.

  Subsequently, the beam angle detection unit 5 assigns peaks that are present on both sides of the peak Pa3 on the horizontal axis in FIG. 7B and that are equal to or higher than the threshold Tha in the order of the surround channel and the front channel from the side closer to Pa3. Determine the radiation angle. That is, the beam angle detection unit 5 uses the angle θa1 (the angle of the test audio beam 45 in FIG. 7A) when the peak Pa1 is obtained as the radiation angle for outputting the Lch audio beam, and the peak Pa2 is obtained. The angle θa2 (angle of the test audio beam 46) at the time of measurement is the radiation angle at which the SLch audio beam is output, and the angle θa4 (angle of the test audio beam 48) when the peak Pa4 is obtained is output as the SRch audio beam. The angle θa5 (the angle of the test audio beam 49) when the peak Pa5 is obtained is the emission angle at which the Rch audio beam is output. Thus, the optimum radiation angle for outputting the sound of each channel can be obtained, and the beam angle detection unit 5 notifies the control unit 6 of the obtained radiation angle.

  After the end of the radiation angle detection process, the control unit 6 performs directivity setting for the beam control unit 8 (step S7). First, the control unit 6 sets a focus in the direction of the radiation angle θa3 of the Cch sound beam, and the delay of the delay unit 80-C so that the Cch sound radiated from each speaker unit 101 simultaneously reaches this focus. The time is calculated for each speaker unit, and the calculated delay time is set in the delay unit 80-C. The delay time for each speaker unit can be uniquely calculated based on the spatial coordinates of the speaker units 101-1 to 101-n and the spatial coordinates of the focal point.

  Similarly, the control unit 6 sets a focus in the direction of the radiation angle θa1 of the Lch sound beam, and the delay unit 80-L causes the Lch sound radiated from each speaker unit 101 to reach this focus at the same time. The delay time is calculated, and the delay time is set in the delay unit 80-L. Further, the control unit 6 sets a focus in the direction of the radiation angle θa5 of the Rch sound beam, and the delay of the delay unit 80-R so that the Rch sound radiated from each speaker unit 101 simultaneously reaches this focus. The time is calculated and the delay time is set in the delay unit 80-R. Further, the control unit 6 sets a focus in the direction of the radiation angle θa2 of the SLch sound beam, and the delay of the delay unit 80-SL is performed so that the SLch sound radiated from each speaker unit 101 simultaneously reaches this focus. The time is calculated and the delay time is set in the delay unit 80-SL. Further, the control unit 6 sets a focus in the direction of the radiation angle θa4 of the SRch sound beam, and the delay of the delay unit 80-SR so that the SRch sound radiated from each speaker unit 101 simultaneously reaches this focus. The time is calculated and the delay time is set in the delay unit 80-SR. This completes the directivity setting in step S7.

  With the above settings, when the Lch, Rch, Cch, SLch, and SRch audio signals are input to the speaker array device 1 during normal listening, the Cch audio is received by the user U as shown in FIG. Directly reaches the position, the Lch sound reaches the listening position after being reflected by the left wall 22 of the listening room 20, the Rch sound reaches the listening position after being reflected by the right wall 24, and the SLch sound is reflected from the left wall. The sound is reflected at 22 and further reflected at the rear wall 23 and then reaches the listening position. The SRch sound is reflected at the right wall 24 and further reflected at the rear wall 23 and then reaches the listening position. Thus, the user U can enjoy the 5.1 channel surround sound field at the listening position.

  As described above, according to the present embodiment, it is possible to easily and quickly set the directivity that has been difficult in the conventional speaker array apparatus. In addition, since the test sound beam is swept and the radiation angle of each sound is determined from the measurement result, it is easy for the user regardless of the shape of the listening room where the speaker array device is installed or the arrangement of furniture. Appropriate settings can be made.

  In the present embodiment, the following effects can be obtained by setting the focal length of the test audio beam to the same value as the microphone distance. FIG. 9 is a diagram for explaining the effect of the present embodiment. FIG. 9A is a top perspective view for explaining the influence of the difference in the focal length of the test sound beam on the level measurement. (B) is a figure which shows the measurement data memorize | stored in the level measurement part 4 by the sweep operation | movement of a test audio beam. In FIG. 9B, Da1 is measurement data when the focal length of the test sound beam is longer than the microphone distance, and Da2 is measurement data when the focal length is equal to the microphone distance.

  Both test audio beams 31 and 32 shown in FIG. 9A are output at the radiation angle θ5, but the focal lengths are different. The distance from the speaker array 10 to the focal point F1 of the test sound beam 31 is longer than the microphone distance, and the distance from the speaker array 10 to the focal point F2 of the test sound beam 32 is the same as the microphone distance. The angle θ4 in FIG. 9A is an angle when the microphone 2 is viewed from the speaker array 10.

When the focal length and the microphone distance are equal, the direct sound of the test sound beam reaches the microphone 2 when the radiation angle is in the vicinity of θ4.
On the other hand, the test sound beam 32 output at the radiation angle θ5 deviates from the microphone 2, whereas the test sound beam 31 output at the same angle is partially applied to the microphone 2. When the focal distance is longer than the microphone distance, the radiation angle range in which the direct sound of the test sound beam reaches the microphone 2 is wider than that when the focal distance and the microphone distance are equal.

  In the above-described radiation angle detection process, in order to easily and accurately determine the radiation angle for outputting the sound of each channel, the direct sound of the test sound beam reaches the microphone 2 only when the radiation angle of the test sound beam is θ4, It is preferable that the reflected sound of the test sound beam reaches the microphone 2 at other radiation angles. However, the expansion of the radiation angle range in which the direct sound of the test sound beam reaches the microphone 2 means that the direct sound of the test sound beam affects the measurement data over a wide angle range.

  Due to the influence of such direct sound, the measurement data has a waveform with a wide skirt width of the peak P1 as indicated by Da1 in FIG. 9B. As described above, the beam angle detector 5 detects the peak of the measurement data and detects the radiation angle at which the sound of each channel is output. In the waveform like the measurement data Da1, the reflected sound of the test sound beam is reflected. Since the S / N ratio is significantly deteriorated in the angle range near θ4 due to the direct sound, it is possible to detect the peak P1 of the direct sound corresponding to Cch, but the surround on both sides of the peak P1. There is a possibility that the peak of the reflected sound corresponding to the channel or the front channel cannot be detected. In particular, the closer the reflected sound peak is to the direct sound peak P1, the more difficult it is to detect the reflected sound peak.

  On the other hand, in this embodiment, by setting the focal length of the test sound beam to be the same as the microphone distance, the radiation angle range in which the direct sound of the test sound beam reaches the microphone 2 can be narrowed. The influence on the measurement data can be suppressed. As a result, the measurement data stored in the level measuring unit 4 has a sharp peak P2 and a narrow skirt as shown by Da2 in FIG. 9B, so that the reflected sound S in the angle range near θ4 is reduced. / N ratio can be improved. As a result, in this embodiment, it becomes easy to detect the peak of the reflected sound corresponding to the surround channel and the front channel, and the angle range in which the peak of the reflected sound can be detected can be expanded.

  Note that if the focal length of the test sound beam is shortened, the spread of the beam at the position of the microphone 2 increases, so there is a concern about the deterioration of the angular resolution of the reflected sound. However, the signal band used for the measurement is determined by the speaker array device 1. If the position of the microphone 2 (listening position) is limited so that the focal length of the test sound beam is not significantly shortened with respect to the path distance of the reflected sound, it is set near the maximum frequency where directivity can be controlled as a single beam. The influence of shortening the focal length can be suppressed.

  The determination in step S3 is a process for preventing the focal length of the test sound beam from becoming significantly shorter than the path length of the reflected sound. When the microphone distance obtained in step S2 is equal to or less than the predetermined limit distance (NO in step S3), the control unit 6 displays an error display screen on the display unit 12 and prompts the user to increase the microphone distance (step) S8). After the user corrects the position of the microphone 2, the control unit 6 returns to step S1 and measures the microphone distance again.

  Further, in this embodiment, since the spread of the reflected sound toward the microphone 2 is increased by shortening the focal length of the test sound beam, an obstacle such as furniture localized in the listening room gives measurement accuracy. The influence can be mitigated, and a radiation angle close to the actual audibility can be detected.

  The present invention can be applied to a speaker array device.

It is a block diagram which shows the structure of the speaker array apparatus which concerns on embodiment of this invention. It is a front view which shows the example of arrangement | positioning of the speaker unit of the speaker array of FIG. It is a figure for demonstrating the principle of directivity control by a speaker array apparatus. It is a figure which represents typically the process of the beam control part in the speaker array apparatus of FIG. It is a flowchart which shows the operation | movement at the time of the sound beam setting mode of the speaker array apparatus of FIG. It is a figure for demonstrating the sweep operation | movement of the test audio | voice beam in embodiment of this invention. It is a figure for demonstrating the radiation angle detection process in embodiment of this invention. It is a top perspective view showing a surround system realized by a speaker array in an embodiment of the present invention. It is a figure for demonstrating the effect of the speaker array apparatus of FIG. It is an upper surface perspective view which shows the example which implement | achieves a surround system with a speaker array apparatus single-piece | unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Speaker array apparatus, 2 ... Microphone, 3 ... A / D converter, 4 ... Level measurement part, 5 ... Beam angle detection part, 6 ... Control part, 7 ... Measurement signal generation part, 8 ... Beam control part, 9 ... Amplifier 10, speaker array 11, operation unit 12, display unit

Claims (3)

A speaker array comprising a plurality of speaker units arranged in a matrix or a line;
During normal listening, a delay time is added to each of multi-channel audio signals input from the outside, and the speaker array is radiated with different directivities according to the multi-channel audio signals. Directivity control means for driving
A sound beam sweeping means for radiating a test sound beam corresponding to the measurement signal from the speaker array and performing a sweep for gradually changing the radiation angle of the test sound beam when setting the directivity control means;
A microphone that is installed at a listening position of a room in which the speaker array is installed and collects a direct sound and a reflected sound of the test sound beam;
A focal length setting means for setting a focal length of the test sound beam to the same value as a microphone distance from the speaker array to the microphone at the time of the sweep;
Storage means for storing, as measurement data, the relationship between the signal level of the sound collected by the microphone during the sweep and the radiation angle of the test sound beam;
Angle detection means for obtaining, for each channel, a radiation angle at which the multi-channel sound should be output from a signal peak of measurement data stored in the storage means and a radiation angle of a test sound beam when the signal peak is obtained; ,
Directivity setting for determining the directivity of the multi-channel sound for each channel from the radiation angle obtained by the angle detection means, and setting the delay time corresponding to this directivity for each channel in the directivity control means And a speaker array device. The speaker array device according to claim 1, wherein
Further, the speaker array apparatus further comprises microphone distance measuring means for measuring the microphone distance before the test sound beam is swept. The speaker array device according to claim 1, wherein
Further, a measurement signal setting means for setting the frequency band of the measurement signal to the highest frequency at which directivity can be controlled by the speaker array;
A microphone that determines whether or not the microphone distance is longer than a predetermined limit distance before sweeping the test sound beam, and if the microphone distance is equal to or less than the limit distance, a microphone that prompts the user to correct the position of the microphone A speaker array device comprising: a distance determination unit.

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