Loud speaker system

Abstract

To provide a loud speaker system that enables a plurality of listeners existing at a specific location to listen sound in a wide frequency range from low-pitched sound to high-pitched sound.SOLUTION: A loud speaker system 100 comprises: an audio sound output portion 110 outputting output-object sound; a loud speaker array 120 including a plurality of loud speakers 122; and a loud speaker drive portion 130 that extracts a plurality of frequency components having different frequencies from an audio sound signal and selectively drives one or more loud speakers 122 using a signal of each of the plurality of frequency components. Depending on the width of a directional characteristic of each of the plurality of frequency components, each of the plurality of frequency components is input to the one or more loud speakers 122.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a speaker system combining a plurality of speakers.

Background Art

[0002] Conventionally, a speaker system has been known in which directivity with respect to a signal in a wide frequency band is controlled by combining a plurality of speakers (see, for example, Patent Document 1). In this speaker system, by setting the characteristics of filters corresponding to each of the plurality of speakers, it is possible to realize different directivities for each of the bass component and the treble component.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the speaker system disclosed in Patent Document 1 described above, it is possible to output sounds of various frequency components such as a bass component and a treble component toward a listener (user) at a specific location. However, generally, the width of the directivity characteristic of the sound output from the speaker changes according to the frequency of the sound. Specifically, when the frequency of the sound is high, the directivity characteristic becomes narrow, and as the frequency of the sound becomes lower, the directivity characteristic becomes wider. Therefore, for example, when there are a plurality of listeners extending horizontally at a position facing the speaker, all of the bass components of the sound reach all the listeners, but for the treble component, it may reach only one of the listeners, and the other listeners may not be able to hear it sufficiently.

[0005] The present invention has been created in view of such points, and its object is to provide a speaker system in which a plurality of listeners at a specific location can listen to sounds in a wide frequency range from low to high frequencies.

Means for Solving the Problems

[0006] In order to solve the above-described problems, the speaker system of the present invention includes output sound generation means for outputting sound to be output, a speaker array including a plurality of speakers, and a plurality of frequency components having different frequencies are extracted from the output sound of the output sound generation means, and one or more speakers are selectively driven by the signals of these plurality of frequency components, and each of the plurality of frequency components is input to one or more speakers in accordance with the width of the directivity characteristic of each of the plurality of frequency components.

[0007] By switching the speakers driven for each frequency component, when radiating from the same number of speakers, it is possible to widen the directivity characteristic of the radiated sound that becomes narrower as the frequency increases, and a plurality of listeners at a specific location can listen to sounds in a wide frequency range from low to high frequencies.

[0008] Further, it is desirable that the above-described high-frequency components correspond to one or more speakers arranged in a narrow range, and the low-frequency components correspond to a plurality of speakers arranged in a wide range. Also, it is desirable that the above-described high-frequency components correspond to a small number of speakers arranged in a narrow range, and the low-frequency components correspond to a large number of speakers arranged in a wide range. In this way, by varying the range of speaker arrangement and the number of speakers for each frequency component, it becomes possible to arbitrarily set the width of the directivity characteristic for each frequency band.

[0009] Further, it is desirable to further include gain adjustment means for adjusting the output level of the speaker array corresponding to at least a part of the plurality of frequency components described above. Thereby, it becomes possible to eliminate the difference in the output level for each frequency component when radiating sound from different numbers of speakers corresponding to each frequency component.

[0010] Also, it is desirable to make the number of speakers corresponding to each of the plurality of frequency components described above the same. This makes it easy to eliminate the difference in output levels for each frequency component.

[0011] Also, it is desirable that the above-described high-frequency components correspond to speakers arranged in a narrow range, and the low-frequency components correspond to speakers arranged in a wide range. This makes it possible to simultaneously adjust the width of the directivity characteristics and the output level for each frequency component.

Brief Description of the Drawings

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[0013] Hereinafter, a speaker system according to an embodiment to which the present invention is applied will be described with reference to the drawings.

[0014] FIG. 1 is a diagram showing the configuration of a speaker system according to an embodiment. The speaker system 100 shown in FIG. 1 is for emitting sound corresponding to an input audio sound signal toward a plurality of listeners in a specific area. For this purpose, the speaker system 100 includes an audio sound output unit 110, a speaker array 120, and an SP (speaker) drive unit 130. The audio sound output unit 110 corresponds to output sound generation means, and the SP drive unit 130 corresponds to speaker drive means, respectively.

[0015] The audio sound output unit 110 outputs an audio sound signal to be radiated toward a plurality of listeners. For example, it is assumed to be the output sound in a receiver such as a terrestrial digital broadcast or a satellite broadcast, but it may be the output sound of a video distributed over the network, or the output sound without video obtained by reproducing the audio sound recorded on a CD, a semiconductor memory, etc.

[0016] The speaker array 120 includes a plurality of speakers 122 to which the frequency components included in the audio sound signal output from the audio sound output unit 110 are selectively input. This speaker array 120 is installed at a position facing a plurality of listeners.

[0017] FIG. 2 is a diagram showing an example of the speaker array 120. As shown in FIG. 2, the speaker array 120 of the present embodiment has 16 columns each in the vertical and horizontal directions, and a total of 256 speakers 122 are arranged without gaps.

[0018] By emitting audio sound from a speaker array 120 composed of a plurality of speakers 122 as shown in FIG. 2, the directivity characteristics of the emitted sound can be narrowed, so that only the listener located mainly in front of the speaker array 120 can listen to the audio sound, and unnecessary audio sound can be prevented from reaching a third party located at other positions.

[0019] FIG. 3 is a diagram showing the positional relationship between the speaker array 120 and the listener. In the example shown in FIG. 3, the speaker array 120 is installed in a part of the display device 500 included in the receiver of the terrestrial digital broadcast, and it is assumed that audio sound is provided to the listener M1 in a predetermined region p1 facing the display device 500 and the listener M2 in the regions p2 on both sides thereof. By using the speaker array 120, the directivity characteristics of the emitted sound can be narrowed, so that this emitted sound (audio sound) can be made audible to the listeners M1 and M2 in the regions p1 and p2.

[0020] Incidentally, the width of the directivity characteristics of the emitted sound of the speaker array 120 depends on the number of speakers 122 (spatial spread) constituting the speaker array 120 and the frequency of the emitted sound. Generally, the fewer the number of speakers 122 (the narrower the spatial spread) constituting the speaker array 120, the wider the directivity characteristics become. Conversely, the more the number of speakers 122 (the wider the spatial spread) constituting the speaker array 120, the narrower the directivity characteristics become. Also, the higher the frequency of the emitted sound, the narrower the directivity characteristics become. Conversely, the lower the frequency of the emitted sound, the wider the directivity characteristics become.

[0021] For these reasons, for the three listeners M1 and M2 in the regions p1 and p2 shown in FIG. 3, even if the low-frequency component of the emitted sound can reach sufficiently, only the central listener M1 can listen to the high-frequency component of the emitted sound, and it is difficult for the listeners M2 on both sides thereof to hear it.

[0022] Therefore, in this embodiment, for the bass components, all 256 speakers 122 that make up the speaker array 120 are used to emit the audio sound, and as the frequency increases, the number of speakers 122 that emit the audio sound is reduced (the spatial spread is narrowed).

[0023] Specifically, in this embodiment, for four frequency bands of 500 Hz or less, 1 kHz or less, 2 kHz or less, and 4 kHz or less, the number of speakers 122 that radiate the audio sound is switched.

[0024] Figs. 4 to 7 are diagrams showing the relationship between the frequency band and the speakers 122. Assuming that the frequency band of 4 kHz or less is switched in four steps, four regions are set within the speaker array 120. The region s1 (Fig. 4) including a total of four speakers 122 (122a) in two columns each in the vertical and horizontal directions closest to the center corresponds to the highest frequency band (2 kHz or more). Also, the region s2 (Fig. 5) including a total of 16 speakers 122 (122a, 122b) in one column surrounding the region s1 corresponds to the next highest frequency band (1 kHz or more). Further, the region s3 (Fig. 6) including a total of 64 speakers 122 (122a, 122b, 122c) in two columns surrounding the region s2 corresponds to the next highest frequency band (500 Hz or more). Furthermore, the region s4 (Fig. 7) including a total of 256 speakers 122 (122a, 122b, 122c, 122d) in four columns surrounding the region s3 corresponds to the entire frequency band including the lowest frequency. In this way, when the frequency is doubled, by narrowing the range where the speakers 122 are arranged to 1 / 2 times, it becomes possible to make the widths of the directivity characteristics of the radiated sound corresponding to each frequency band substantially the same.

[0025] The SP drive unit 130 extracts four different types of frequency components from the audio sound signal output from the audio sound output unit 110, amplifies the signals, and inputs them to the corresponding speakers 122 (122a to 122d) within the speaker array 120 to drive each speaker 122.

[0026] For this purpose, the SP driving unit 130 includes three LPFs (low-pass filters) 132, 134, and 136. The cut-off frequency of the LPF 132 is set to 2 kHz, and it extracts signals with frequency components lower than 2 kHz from the audio sound signal. Also, the cut-off frequency of the LPF 134 is set to 1 kHz, and it extracts signals with frequency components lower than 1 kHz from the audio sound signal. The cut-off frequency of the LPF 136 is set to 500 Hz, and it extracts signals with frequency components lower than 500 Hz from the audio sound signal.

[0027] When an audio sound signal is input to the SP driving unit 130 having such a configuration, the audio sound signal itself is input to the speaker 122a (Fig. 4), and signals with frequency components of 2 kHz or less are input to the speakers 122a and 122b (Fig. 5), signals with frequency components of 1 kHz or less are input to the speakers 122a, 122b, and 122c (Fig. 6), and signals with frequency components of 500 Hz or less are input to the speakers 122a, 122b, 122c, and 122d (Fig. 7), thereby driving each speaker 122 included in the speaker 120. Note that although an amplifier for amplifying the signal and driving each speaker 122 is included in front of each speaker 122, it is omitted in Fig. 1. When the above-described content is organized in terms of frequency bands, it is as follows.

[0028] (1a) The signal with frequency components of 500 Hz or less included in the audio sound is directly input to the speaker 122a and is also extracted through the LPFs 132, 134, and 136 and input to the speakers 122b, 122c, and 122d. That is, the signal with frequency components of 500 Hz or less is input to all the speakers 122 included in the area s4 of the speaker array 120. In this way, the range of the directivity characteristics is set so that the sound with frequency components radiated from each of the speakers 122a to 122d reaches the three listeners M1 and M2 in the areas p1 and p2 shown in Fig. 3.

[0029] (2a) The signals of the frequency components from 500 to 1 kHz included in the audio sound are directly input to the speaker 122a and are also extracted through the LPFs 132 and 134 and input to the speakers 122b and 122c. That is, the signals of the frequency components from 500 to 1 kHz are input only to the speakers 122a, 122b, and 122c included in the region s3 closer to the center of the speaker array 120. In this way, the sound of the frequency components radiated from some of the speakers 122a to 122c has a narrower radiation sound directivity characteristic by the amount that the frequency is higher than the frequency components of 500 Hz or less. However, by reducing the location range of the speakers 122a, 122b, and 122c that radiate the sound by that amount, a range of directivity characteristics comparable to the case of (1a) described above is ensured.

[0030] (3a) The signals of the frequency components from 1 to 2 kHz included in the audio sound are directly input to the speaker 122a and are also extracted through the LPF 132 and input to the speaker 122b. That is, the signals of the frequency components from 1 to 2 kHz are input only to the speakers 122a and 122b included in the region s2 closer to the center of the speaker array 120. In this way, the sound of the frequency components radiated from some of the speakers 122a and 122b has an even narrower radiation sound directivity characteristic by the amount that the frequency is higher than the frequency components of 1 kHz or less. However, by further reducing the location range of the speakers 122a and 122b that radiate the sound by that amount, a range of directivity characteristics comparable to the cases of (1a) and (2a) described above is ensured.

[0031] (4a) The signals of the frequency components of 2 kHz or higher included in the audio sound are directly input to the speaker 122a and cannot pass through the LPFs 132, 134, and 136. That is, the signals of the frequency components of 2 kHz or higher are input only to the speaker 122a included in the region s1 closer to the center of the speaker array 120. In this way, the sound of the frequency components radiated from some of the speakers 122a has a narrower radiation sound directivity characteristic by a higher frequency than the frequency components of 2 kHz or lower. However, by further reducing the location range of the speakers 122a that radiate the sound by that amount, a range of directivity characteristics comparable to each of the cases (1a), (2a), and (3a) described above is ensured.

[0032] In this way, in the speaker system 100 of the present embodiment, by switching the speakers 122 driven for each frequency band, it is possible to widen the directivity characteristic of the radiation sound that becomes narrower as the frequency increases when radiating from the same number of speakers 122, and all of the plurality of listeners M1 and M2 at a specific location (predetermined regions p1 and p2) can listen to sounds in a wide frequency band from low to high. In particular, by varying the arrangement range of the speakers 122 and the number of speakers 122 for each frequency band, it is possible to arbitrarily set the width of the directivity characteristic for each frequency band.

[0033] FIG. 8 is a diagram showing the configuration of a speaker system according to a modified example. The speaker system 100A shown in FIG. 8 is different from the speaker system 100 shown in FIG. 1 in that the SP drive unit 130 is replaced with an SP drive unit 130A.

[0034] The SP drive unit 130A extracts four different types of frequency components from the audio sound signal output from the audio sound output unit 110, adjusts the gain, and then amplifies the signal and inputs it to the corresponding speakers 122 (122a to 122d) in the speaker array 120 to drive each speaker 122.

[0035] For this purpose, the SP drive unit 130A includes four BPFs (band-pass filters) 240, 242, 244, 246, three gain adjustment filters 252, 254, 256, and three adders 260, 262, 264. The filters 252, 254, 256 correspond to the gain adjustment means.

[0036] The BPF 240 extracts components in the frequency band of 2 kHz or higher from the audio sound signal. The BPF 242 extracts components in the frequency band of 1 to 2 kHz from the audio sound signal. The BPF 244 extracts components in the frequency band of 500 to 1 kHz from the audio sound signal. The BPF 246 extracts components in the frequency band of 500 Hz or lower from the audio sound signal.

[0037] The filter 252 performs gain adjustment on the components in the frequency band of 1 to 2 kHz output from the BPF 242 with a gain g1. Also, the filter 254 performs gain adjustment on the components in the frequency band of 500 to 1 kHz output from the BPF 244 with a gain g2. The filter 256 performs gain adjustment on the components in the frequency band of 500 Hz or lower output from the BPF 246 with a gain g3. The signal after this gain adjustment is input to the speaker 122d (Fig. 7) and the adder 264.

[0038] In the speaker system 100 shown in Fig. 1, the number of speakers 122 corresponding to each frequency band is not the same. In the lower frequency band, more speakers 122 radiate, and as the frequency band becomes higher, the number of speakers 122 decreases. Therefore, there is a difference in the output level for each frequency band. In this modification, this point is improved, and the gains of the filters 252, 254, 256 are set such that g1 > g2 > g3 (the degree of signal attenuation increases in the order of the filters 252, 254, 256). As a result, the difference in the output level for each frequency band is eliminated.

[0039] The adder 264 adds the signal in the frequency band of 500 Hz or less output from the BPF 246 and gain-adjusted by the filter 256, and the signal in the frequency band of 500 to 1 kHz output from the BPF 244 and gain-adjusted by the filter 254. This added signal is input to the speaker 122c (Fig. 6) and the adder 262.

[0040] The adder 262 adds the signal in the frequency band of 1 kHz or less output from the adder 264 and gain-adjusted, and the signal in the frequency band of 1 to 2 kHz output from the BPF 242 and gain-adjusted by the filter 252. This added signal is input to the speaker 122b (Fig. 5) and the adder 260.

[0041] The adder 260 adds the signal in the frequency band of 2 kHz or less output from the adder 262 and gain-adjusted, and the component in the frequency band of 2 kHz or more output from the BPF 240. This added signal is input to the speaker 122a (Fig. 4).

[0042] When an audio sound signal is input, the SP drive unit 130A having such a configuration inputs the signal after gain-adjusting all frequency components included in this audio sound signal to the speaker 122a (Fig. 4), inputs the signal in which each frequency component is gain-adjusted and is 2 kHz or less to the speakers 122a and 122b (Fig. 5), inputs the signal in which each frequency component is gain-adjusted and is 1 kHz or less to the speakers 122a, 122b, and 122c (Fig. 6), and inputs the signal in which each frequency component is gain-adjusted and is 500 Hz or less to the speakers 122a, 122b, 122c, and 122d (Fig. 7), thereby driving each speaker 122 included in the speaker 120. Although an amplifier for amplifying the signal and driving each speaker 122 is included in front of each speaker 122, it is omitted in Fig. 8. When the above-described content is organized for each frequency band, it is as follows.

[0043] (1b) The signal of the frequency component below 500 Hz included in the audio sound is extracted through BPF264, and after being further gain-adjusted through filter 256, it is input to speakers 122a to 122d. That is, the signal of the frequency component below 500 Hz is gain-adjusted for each frequency band and then input to all the speakers 122 included in region s4 of the speaker array 120. In this way, the sound of the frequency component radiated from each of the speakers 122a to 122d has its directivity characteristic range set so as to reach the three listeners M1, M2 in regions p1, p2 shown in FIG. 3.

[0044] (2b) The signal of the frequency component of 500 to 1 kHz included in the audio sound is extracted through BPF244, and after being further gain-adjusted through filter 254, it is input to speakers 122a to 122c. That is, the signal of the frequency component of 500 to 1 kHz is gain-adjusted for each frequency band and then input only to speakers 122a, 122b, 122c included in region s3 closer to the center of the speaker array 120. In this way, although the directivity characteristic of the radiated sound becomes narrower for the frequency component of 500 to 1 kHz than for the frequency component below 500 Hz by the amount of the higher frequency, by making the location range of the speakers 122a, 122b, 122c that radiate the sound smaller by that amount, a directivity characteristic range comparable to the case of (1b) described above is ensured.

[0045] (3b) The signal of the frequency component of 1 - 2 kHz included in the audio sound is extracted through BPF242. After further gain adjustment through filter 252, it is input to speakers 122a and 122b. That is, the signal of the frequency component of 1 - 2 kHz is input only to speakers 122a and 122b included in the region s2 closer to the center of the speaker array 120 after gain adjustment for each frequency band. In this way, the sound of the frequency component radiated from some of the speakers 122a and 122b has a more narrow radiation directivity characteristic by a higher frequency than the frequency component of 1 kHz or less, but by making the location range of the speakers 122a and 122b that radiate the sound smaller by that amount, a range of directivity characteristics comparable to the cases of (1b) and (2b) described above is ensured.

[0046] (4b) The signal of the frequency component of 2 kHz or more included in the audio sound is directly input to speaker 122a. That is, the signal of the frequency component of 2 kHz or more is input only to speaker 122a included in the region s1 closer to the center of the speaker array 120. In this way, the sound of the frequency component radiated from some of the speakers 122a has a more narrow radiation directivity characteristic by a higher frequency than the frequency component of 2 kHz or less, but by making the location range of the speaker 122a that radiates the sound smaller by that amount, a range of directivity characteristics comparable to each of the cases of (1b), (2b), and (3b) described above is ensured.

[0047] Thus, in the speaker system 100A of this modification example, gain adjustment is performed for each frequency band using filters 252, 254, and 256, and it is possible to eliminate the difference in the output level for each frequency component when different numbers of speakers 122 radiate sound corresponding to each frequency component.

[0048] FIG. 9 is a diagram showing the configuration of a speaker system of another modification example. The speaker system 100B shown in FIG. 9 is different from the speaker system 100 shown in FIG. 1 in that the SP drive unit 130 is replaced with an SP drive unit 130B and the speaker array 120 is replaced with a speaker array 220.

[0049] The SP driving unit 130B extracts three different types of frequency components from the audio sound signal output from the audio sound output unit 110, amplifies the signal, and inputs it to the corresponding speakers 222 (222a, 222b, 222c, 222d) in the speaker array 220 to drive each speaker 222.

[0050] For this purpose, the SP driving unit 130B includes three BPFs (band-pass filters) 340, 342, 344 and two adders 350, 352.

[0051] The BPF 340 extracts the high-frequency component from the audio sound signal. The signal of this high-frequency component is input to the speaker 222b included in the speaker array 220 and the adder 350. The BPF 342 extracts the mid-frequency component from the audio sound signal. The signal of this mid-frequency component is input to the speaker 222c included in the speaker array 220 and the adder 352. The BPF 344 extracts the low-frequency component from the audio sound signal. The signal of this low-frequency component is input to the speaker 222d included in the speaker array 220 and the adder 350.

[0052] The adder 350 adds the signal of the high-frequency component output from the BPF 340 and the signal of the low-frequency component output from the BPF 344. The added signal is input to the adder 352. The adder 352 adds the signal output from the adder 350 (the signal including the high-frequency component and the low-frequency component) and the signal of the mid-frequency component output from the BPF 342. The added signal is input to the speaker 222a included in the speaker array 220.

[0053] When an audio sound signal is input to the SP drive unit 130B having such a configuration, the high-frequency component included in the audio sound signal is extracted by the BPF 340 and input to the speakers 222a and 222b directly or via the adders 350 and 352. The mid-frequency component included in the audio sound signal is extracted by the BPF 342 and input to the speakers 222a and 222c directly or via the adder 352. The low-frequency component included in the audio sound signal is extracted by the BPF 344 and input to the speakers 222a and 222d directly or via the adder 350, thereby driving each speaker 222 included in the speaker 220. Although an amplifier for amplifying the signal and driving each speaker 222 is included in front of each speaker 222, it is omitted in FIG. 9. When the above-described content is organized for each frequency band, it becomes as follows.

[0054] (1c) The signal of the low-frequency component included in the audio sound is input to the speakers 222d and 222a of the speaker array 220.

[0055] In this modification, in the speaker array 220, the speaker 222a is arranged at the center, the speaker 222b is arranged at a position adjacent to the speaker 222a (distance D1 from the central speaker 222a), the speaker 222c is arranged at an outer position (distance D2 (> D1) from the central speaker 222a), and the speaker 222d is arranged at a further outer position (distance D3 (> D2) from the central speaker 222a).

[0056] In such a speaker array 220, the signal of the low-frequency component is input to the central speaker 222a and the outermost both-end speakers 222d. In this way, the range of the directivity characteristic is set so that the sound of the low-frequency component radiated from the speakers 222a and 222d arranged in the widest range reaches the three listeners M1 and M2 in the regions p1 and p2 shown in FIG. 3.

[0057] (2c) The signals of the midrange components included in the audio sound are input to the speakers 222c and 222a of the speaker array 220. The midrange component sounds radiated from these speakers 222a and 222c have a narrower radiation sound directivity characteristic than the low-frequency component sounds by an amount corresponding to their higher frequency. However, by reducing the location range of the speakers 222a and 222c that radiate the sound by that amount, a directivity characteristic range comparable to the case of (1c) described above is ensured.

[0058] (3c) The signals of the high-frequency components included in the audio sound are input to the speakers 222b and 222a of the speaker array 220. The high-frequency component sounds radiated from these speakers 222a and 222b have an even narrower radiation sound directivity characteristic than the midrange component sounds by an amount corresponding to their even higher frequency. However, by further reducing the location range of the speakers 222a and 222b that radiate the sound by that amount, a directivity characteristic range comparable to the cases of (1c) and (2c) described above is ensured.

[0059] Also, in this modification, in all cases of (1c) to (3c) described above, the number of speakers 222 that radiate the sound of each frequency band can be made the same. For this reason, without using filters 252, 254, 256, etc. shown in FIG. 8, the difference in output levels when radiating the sound of each frequency band is eliminated.

[0060] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the gist of the present invention. In the speaker array 120 shown in FIGS. 4 to 7, the number of speakers 122 in the vertical and horizontal directions is variable corresponding to the frequency components of the audio sound. However, as shown in FIG. 3, when switching the directivity characteristic for each frequency component of the radiation sound in one direction (horizontal direction), the number of speakers may be made variable according to that direction.

[0061] Figures 10 to 13 are diagrams showing another example of varying the number of speakers according to the frequency band. Assuming that the frequency band of 4 kHz or less is divided into four, the fact that four regions are set within the speaker array 320 is the same as the example shown in FIG. 4. The region s1 (FIG. 10) containing a total of 32 speakers 322 in the two innermost vertical columns contains the highest frequency band (2 kHz or more). Also, the region s2 (FIG. 11) containing a total of 64 speakers 322 in the one column on each side surrounding the region s1 contains the next highest frequency band (1 kHz to 2 kHz). Also, the region s3 (FIG. 12) containing a total of 128 speakers 322 in the two columns on each side surrounding the region s2 contains the next highest frequency band (500 Hz to 1 kHz). Further, the region s4 (FIG. 13) containing a total of 256 speakers 322 in the four columns on each side surrounding the region s3 corresponds to the entire frequency band including the lowest frequency. Thus, when the frequency is doubled, by narrowing the horizontal range in which the speakers 322 are arranged to 1 / 2 times, it becomes possible to substantially match the widths of the horizontal directivity characteristics of the radiated sound corresponding to each frequency band.

[0062] Figure 14 is a diagram showing another example of varying the number of speakers according to the frequency band. In the example shown in FIGS. 10 to 13, the speaker array 320 was configured by 256 speakers 322 in 16 columns vertically and horizontally, but for example, the number of speakers 322 in the vertical direction may be changed. In the example shown in FIG. 14, the speaker array 320 is configured by 16 speakers 322 in one column vertically. The frequency bands corresponding to each of FIGS. 14(A), 14(B), 14(C), and 14(D) are the same as the frequency bands corresponding to each of FIGS. 10 to 13.

[0063] Also, in the modified example shown in FIG. 9, the number of speakers 222 corresponding to each frequency component was made the same, but it is not necessarily required to make the numbers the same. Also, in this case, gain adjustment may be performed as in the speaker system 100A shown in FIG. 8 according to the difference.

Industrial Applicability

[0064] As described above, according to the present invention, by switching speakers to be driven differently for each frequency component, it is possible to adjust so that the directivity characteristics of the radiated sound, which become narrower as the frequency increases when radiated from the same speaker, become wider, and a plurality of listeners at a specific location can listen to sounds in a wide frequency range from low to high frequencies.

Explanation of Signs

[0065] 100, 100A, 100B Speaker System 110 Audio Sound Output Unit 120, 220, 320 Speaker Array 122, 222, 322 Speaker 130, 130A, 130B SP (Speaker) Driver 132, 134, 136 LPF (Low Pass Filter) 240, 242, 244, 246 BPF (Band Pass Filter) 252, 254, 256 Filter 260, 262, 264 Adder 340, 342, 344 BPF 350, 352 Adder

Claims

1. Output sound generation means for outputting a sound to be output; A speaker array including a plurality of speakers; Speaker driving means for extracting a plurality of frequency components having different frequencies from the output sound of the output sound generation means and selectively driving one or more of the plurality of speakers with signals of the respective frequency components; A speaker system comprising: inputting each of the plurality of frequency components to one or more of the plurality of speakers according to the width of the directivity characteristic of each of the plurality of frequency components.

2. The speaker system according to claim 1, wherein the high frequency components correspond to one or more speakers arranged in a narrow range, and the low frequency components correspond to a plurality of speakers arranged in a wide range.

3. The speaker system according to claim 2, wherein the high frequency components correspond to a small number of speakers arranged in the narrow range, and the low frequency components correspond to a large number of speakers arranged in the wide range.

4. The speaker system according to claim 1, further comprising gain adjustment means for adjusting the output level of the speaker array corresponding to at least a part of the plurality of frequency components.

5. The speaker system according to claim 1, wherein the number of speakers corresponding to each of the plurality of frequency components is made the same.

6. The speaker system according to claim 5, wherein the high frequency components correspond to the speakers arranged in a narrow range, and the low frequency components correspond to the speakers arranged in a wide range.

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