Loudspeaker system

Abstract

The present invention addresses the problem of providing a speaker system in which a plurality of audiences located in a specific location can hear sounds in a wide frequency range from low pitch to high pitch. A solution is provided. A speaker system (100) provided with: an audio sound output unit (110) for outputting sound to be output; a speaker array (120) comprising a plurality of speakers (122); and a method for selectively driving one or more speakers (122) by extracting a plurality of frequency components having different frequencies from an audio sound signal and by means of a signal for each of the plurality of frequency components and a speaker drive unit (130). Each of the plurality of frequency components is input to the one or more speakers (122) in accordance with the width of the directivity characteristics of each of the plurality of frequency components.

Description

Technical Field

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

[0002] A speaker system is conventionally known in which directivity corresponding to a wide-band signal is controlled by combining a plurality of speakers (for example, see Patent Document 1). In this speaker system, by setting the characteristics of filters corresponding to the respective speakers among the plurality of speakers, different directivities can be achieved for the bass component and the treble component, respectively.

[0003] Prior Art Documents:

[0004] Patent Documents:

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-68398 Summary of the Invention

[0006] Problems to be Solved by the Invention:

[0007] In addition, in the speaker system disclosed in Patent Document 1 described above, it is possible to output sounds of various frequency components such as bass components and treble components toward listeners (users) located at a specific place. However, generally, the width of the directivity characteristics of the sound output from the speaker varies according to the frequency of the sound. Specifically, the directivity characteristics are narrow when the frequency of the sound is high, and the directivity characteristics become wider as the frequency of the sound becomes lower. Therefore, for example, when there are a plurality of listeners laterally spaced out in a loose manner at a position facing the speaker, the bass component of the sound reaches 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.

[0008] The present invention has been made in view of the above problems, and an object thereof is to provide a speaker system in which a plurality of listeners located at a specific place can hear sounds in a wide frequency range from bass to treble.

[0009] Means for Solving the Problems:

[0010] To solve the above problems, the speaker system of the present invention includes: an output sound generation mechanism that outputs a sound to be output; a speaker array including a plurality of speakers; and a speaker drive mechanism that extracts a plurality of frequency components having different frequencies from the output sound of the output sound generation mechanism and selectively drives one or more speakers by signals of the respective frequency components among the plurality of frequency components, and the speaker system inputs the respective frequency components among the plurality of frequency components to one or more speakers in accordance with the width of the directivity characteristics of the respective frequency components among the plurality of frequency components.

[0011] By switching the driven speakers for each frequency component, it is possible to widen the directivity characteristics of the radiated sound that becomes narrower as the frequency increases when radiated from the same number of speakers, and multiple listeners located in a specific place can hear sounds in a wide frequency range from low to high frequencies.

[0012] In addition, it is preferable that the above high-frequency components correspond to one or more speakers arranged in a narrow range, while the low-frequency components correspond to multiple speakers arranged in a wide range. In addition, it is preferable that the above high-frequency components correspond to a small number of speakers arranged in a narrow range, while the low-frequency components correspond to a large number of speakers arranged in a wide range. In this way, by changing the arrangement range of the speakers or the number of speakers for each frequency component, the width and narrowness of the directivity characteristics of each frequency band can be arbitrarily set.

[0013] In addition, it is preferable that there is also provided: a gain adjustment mechanism that adjusts the output level of the speaker array corresponding to at least a part of the above multiple frequency components. Thereby, when radiating sounds from different numbers of speakers corresponding to each frequency component, the difference in the output levels of each frequency component can be eliminated.

[0014] In addition, it is preferable that the number of speakers corresponding to each of the above multiple frequency components is the same. Thereby, it is easy to eliminate the difference in the output levels of each frequency component.

[0015] In addition, it is preferable that the above high-frequency components correspond to speakers arranged in a narrow range, while the low-frequency components correspond to speakers arranged in a wide range. Thereby, it is possible to adjust both the width and narrowness of the directivity characteristics and the output level of each frequency component simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a diagram showing the configuration of a speaker system according to an embodiment.

[0017] Figure 2 is a diagram showing an example of a speaker array.

[0018] Figure 3 is a diagram showing the positional relationship between the speaker array and the listeners.

[0019] Figure 4 is a diagram showing the relationship between frequency bands and speakers.

[0020] Figure 5 is a diagram showing the relationship between frequency bands and speakers.

[0021] Figure 6 is a diagram showing the relationship between frequency bands and speakers.

[0022] Figure 7 It is a diagram showing the relationship between the frequency band and the speaker.

[0023] Figure 8 It is a diagram showing the configuration of a speaker system of a modified example.

[0024] Figure 9 It is a diagram showing the configuration of a speaker system of another modified example.

[0025] Figure 10 It is a diagram showing another example of changing the number of speakers corresponding to the frequency band.

[0026] Figure 11 It is a diagram showing another example of changing the number of speakers corresponding to the frequency band.

[0027] Figure 12 It is a diagram showing another example of changing the number of speakers corresponding to the frequency band.

[0028] Figure 13 It is a diagram showing another example of changing the number of speakers corresponding to the frequency band.

[0029] Figure 14 It is a diagram showing another example of changing the number of speakers corresponding to the frequency band.

[0030] Explanation of reference numerals:

[0031] 100, 100A, 100B Speaker system

[0032] 110 Audio sound output section

[0033] 120, 220, 320 Speaker array

[0034] 122, 222, 322 Speaker

[0035] 130, 130A, 130B SP (Speaker) drive section

[0036] 132, 134, 136 LPF (Low-pass filter)

[0037] 240, 242, 244, 246 BPF (Band-pass filter)

[0038] 252, 254, 256 Filter

[0039] 260, 262, 264 Adder

[0040] 340, 342, 344 BPF

[0041] 350, 352 Adder Detailed implementation mode

[0042] Hereinafter, a loudspeaker system to which one embodiment of the present invention is applied will be described with reference to the accompanying drawings.

[0043] Figure 1 It is a diagram showing the configuration of a loudspeaker system according to one embodiment. Figure 1 The loudspeaker system 100 shown is for emitting a sound corresponding to an input audio sound signal toward a plurality of listeners located in a specific area. For this purpose, the loudspeaker 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 an output sound generation mechanism, and the SP drive unit 130 corresponds to a speaker drive mechanism.

[0044] The audio sound output unit 110 outputs an audio sound signal to be radiated toward a plurality of listeners. For example, the output sound in a receiver for terrestrial digital broadcasting or satellite broadcasting is envisaged, but it may also be the output sound of a video distributed over a network, or an output sound without an accompanying video obtained by playing an audio sound recorded in a CD or a semiconductor memory, etc.

[0045] The speaker array 120 includes a plurality of speakers 122 that selectively receive frequency components included in the audio sound signal output from the audio sound output unit 110. The speaker array 120 is provided at a position facing the plurality of listeners.

[0046] Figure 2 It is a diagram showing an example of the speaker array 120. As Figure 2 shown, in the speaker array 120 of the present embodiment, a total of 256 speakers 122 arranged in 16 columns each in the horizontal and vertical directions are arranged without gaps.

[0047] By radiating an audio sound from the speaker array 120 composed of a plurality of speakers 122 as Figure 2 shown, the directivity characteristic of the radiated sound can be narrowed, and it is possible to make only the listeners mainly located in front of the speaker array 120 hear the audio sound, and unnecessary audio sound does not reach a third party located at other positions.

[0048] Figure 3 It is a diagram showing the positional relationship between the speaker array 120 and the listeners. In Figure 3 the example shown, it is envisaged that the speaker array 120 is provided in a part of the display device 500 included in a receiver for terrestrial digital broadcasting, and audio sound is provided to the listeners M1 located in the specified area p1 facing the display device 500 and the listeners M2 located in the areas p2 on both sides thereof. By using the speaker array 120, the directivity characteristic of the radiated sound can be narrowed, so that the listeners M1 and M2 located in the areas p1 and p2 can hear the radiated sound (audio sound).

[0049] In addition, the width of the directivity characteristic of the sound radiated by the speaker array 120 depends on the number of speakers 122 (spatial expansion) that make up the speaker array 120 and the frequency of the radiated sound. Generally speaking, the fewer the number of speakers 122 that make up the speaker array 120 (the narrower the spatial expansion), the wider the directivity characteristic. On the contrary, the more the number of speakers 122 that make up the speaker array 120 (the wider the spatial expansion), the narrower the directivity characteristic. In addition, the higher the frequency of the radiated sound, the narrower the directivity characteristic. On the contrary, the lower the frequency of the radiated sound, the wider the directivity characteristic.

[0050] For this reason, regarding Figure 3 the three listeners M1 and M2 located in the regions p1 and p2 as shown, the following situation will occur: Even when the bass component of the radiated sound can reach sufficiently, for the high-frequency component of the radiated sound, only the central listener M1 can hear it, while the listeners M2 on both sides of it can hardly hear it.

[0051] Therefore, in the present embodiment, for the bass component, all (256) speakers 122 that make up the speaker array 120 are used to emit the audio sound. As the frequency increases, the number of speakers 122 that emit the audio sound is reduced (the spatial expansion is made narrower).

[0052] Specifically, in the present embodiment, for the four types of frequency bands below 500 Hz, below 1 kHz, below 2 kHz, and below 4 kHz, the number of speakers 122 that radiate the audio sound is switched.

[0053] Figures 4 - 7 FIG. is a diagram showing the relationship between the frequency band and the speaker 122. It is assumed that the switching is performed in four stages for the frequency band below 4 kHz, and four regions are set within the speaker array 120. The region s1 ( Figure 4 ) corresponding to the highest frequency band (above 2 kHz) includes a total of four speakers 122 (122a) in the two columns in the center and the two columns in the horizontal direction. In addition, the region s2 ( Figure 5 ) corresponding to the second highest frequency band (above 1 kHz) includes the region s1 and a total of 16 speakers 122 (122a, 122b) in one column surrounding the region s1. In addition, the region s3 ( Figure 6 ) corresponding to the third highest frequency band (above 500 Hz) includes the region s2 and a total of 64 speakers 122 (122a, 122b, 122c) in two columns surrounding the region s2. Further, the region s4 ( Figure 7)Corresponds to the entire frequency band including the lowest frequency. In this way, by making the range where the speaker 122 is configured narrower by 1 / 2 times when the frequency doubles, it is possible to make the width of the directivity characteristics of the radiated sound corresponding to each frequency band approximately match.

[0054] The SP driving unit 130 inputs a signal obtained by extracting four different types of frequency components from the audio sound signal output from the audio sound output unit 110 and amplifying it to the corresponding speaker 122 (122a to 122d) in the speaker array 120 to drive each speaker 122.

[0055] For this purpose, the SP driving unit 130 includes three LPFs (low-pass filters) 132, 134, and 136. The LPF 132 is set to a cut-off frequency of 2 kHz and extracts a signal of a frequency component lower than 2 kHz from the audio sound signal. In addition, the LPF 134 is set to a cut-off frequency of 1 kHz and extracts a signal of a frequency component lower than 1 kHz from the audio sound signal. The LPF 136 is set to a cut-off frequency of 500 Hz and extracts a signal of a frequency component lower than 500 Hz from the audio sound signal.

[0056] When the SP driving unit 130 configured in this way is input with an audio sound signal, it inputs the audio sound signal itself to the speaker 122a ( Figure 4 ), inputs the signal of the frequency component below 2 kHz to the speakers 122a and 122b ( Figure 5 ), inputs the signal of the frequency component below 1 kHz to the speakers 122a, 122b, and 122c ( Figure 6 ), and inputs the signal of the frequency component below 500 Hz to the speakers 122a, 122b, 122c, and 122d ( Figure 7 ) to drive each speaker 122 included in the speaker 120. In addition, in front of each speaker 122, there is an amplifier that amplifies the signal and drives each speaker 122, but it is omitted in Figure 1 . The above content is sorted by frequency band as follows.

[0057] (1a) The signal of the frequency component below 500 Hz included in the audio sound is directly input to the speaker 122a and is also extracted by the LPFs 132, 134, and 136 and input to the speakers 122b, 122c, and 122d. That is, the signal of the frequency component below 500 Hz is input to all the speakers 122 included in the area s4 of the speaker array 120. Regarding the sound of the frequency component radiated from each of the speakers 122a to 122d, the range of the directivity characteristics is set so that it reaches the position located at Figure 3Three listeners M1, M2 in regions p1, p2 shown.

[0058] (2a) Signals of the frequency components of 500 to 1 kHz included in the audio sound are directly input to speaker 122a, and are extracted by LPFs 132, 134 and input to speakers 122b, 122c. That is, the signals of the frequency components of 500 to 1 kHz are only input to speakers 122a, 122b, 122c included in the central region s3 of the speaker array 120. The sound of the frequency components radiated from a part of the speakers 122a to 122c has a narrower radiation sound directivity characteristic than the frequency components of 500 Hz or less by an amount corresponding to the increase in frequency, but by reducing the range where the speakers 122a, 122b, 122c that radiate the sound are located by a corresponding amount, a range of directivity characteristics similar to that in the case of (1a) above is ensured.

[0059] (3a) Signals of the frequency components of 1 to 2 kHz included in the audio sound are directly input to speaker 122a, and are extracted by LPF 132 and input to speaker 122b. That is, the signals of the frequency components of 1 to 2 kHz are only input to speakers 122a, 122b included in the central region s2 of the speaker array 120. The sound of the frequency components radiated from a part of the speakers 122a, 122b has a narrower radiation sound directivity characteristic than the frequency components of 1 kHz or less by an amount corresponding to the increase in frequency, but by reducing the range where the speakers 122a, 122b that radiate the sound are located by a corresponding amount, a range of directivity characteristics similar to that in the case of (1a) or (2a) above is ensured.

[0060] (4a) Signals of the frequency components of 2 kHz or more included in the audio sound are directly input to speaker 122a, but cannot pass through LPFs 132, 134, 136. That is, the signals of the frequency components of 2 kHz or more are only input to speaker 122a included in the central region s1 of the speaker array 120. The sound of the frequency components radiated from a part of the speaker 122a has a narrower radiation sound directivity characteristic than the frequency components of 2 kHz or less by an amount corresponding to the increase in frequency, but by reducing the range where the speaker 122a that radiates the sound is located by a corresponding amount, a range of directivity characteristics similar to each of the cases of (1a), (2a), (3a) above is ensured.

[0061] In this way, in the speaker system 100 of the present embodiment, by switching the driven speaker 122 for each frequency band, it is possible to widen the directivity characteristics of the radiation sound that becomes narrower as the frequency increases when radiated from the same number of speakers 122, and all of the multiple listeners M1, M2 located in a specific place (prescribed areas p1, p2) can hear the wide-band sound from bass to treble. In particular, by changing the range of the configuration of the speakers 122 or the number of speakers 122 for each frequency band, the width of the directivity characteristics of each frequency band can be arbitrarily set.

[0062] Figure 8 It is a diagram showing the configuration of a speaker system according to a modified example. Figure 8 The shown speaker system 100A is different from Figure 1 the shown speaker system 100 in that the SP drive unit 130 is replaced with the SP drive unit 130A.

[0063] The SP drive unit 130A inputs a signal obtained by extracting four different types of frequency components from the audio sound signal output from the audio sound output unit 110, performing gain adjustment, and then amplifying it, to the corresponding speakers 122 (122a to 122d) in the speaker array 120 to drive each speaker 122.

[0064] For this purpose, the SP drive unit 130A includes four BPFs (band-pass filters) 240, 242, 244, 246, three filters 252, 254, 256 for gain adjustment, and three adders 260, 262, 264. The filters 252, 254, 256 correspond to the gain adjustment mechanism.

[0065] The BPF 240 extracts the components in the frequency band of 2 kHz or higher from the audio sound signal. The BPF 242 extracts the components in the frequency band of 1 to 2 kHz from the audio sound signal. The BPF 244 extracts the components in the frequency band of 500 to 1 kHz from the audio sound signal. The BPF 246 extracts the components in the frequency band of 500 Hz or lower from the audio sound signal.

[0066] 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. In addition, 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 ( Figure 7 ) and the adder 264.

[0067] In Figure 1In the illustrated speaker system 100, the number of speakers 122 corresponding to each frequency band is not the same. Instead, the lower frequency bands radiate from a larger number of speakers 122, and the higher the frequency band, the fewer the number of speakers 122. Therefore, there are differences in the output levels of each frequency band. In this modification, this point is improved so that the gains of the filters 252, 254, and 256 are in the relationship of g1 > g2 > g3 (the degree of signal attenuation increases in the order of the filters 252, 254, and 256). Thereby, the differences in the output levels of each frequency band are eliminated.

[0068] The adder 264 adds the signal of the frequency band below 500 Hz output from the BPF 246 and gain-adjusted by the filter 256 to the signal of the frequency band from 500 Hz to 1 KHz output from the BPF 244 and gain-adjusted by the filter 254. The added signal is input to the speaker 122c( Figure 6 ) and the adder 262.

[0069] The adder 262 adds the signal of the frequency band below 1 kHz output from the adder 264 and gain-adjusted to the signal of the frequency band from 1 kHz to 2 kHz output from the BPF 242 and gain-adjusted by the filter 252. The added signal is input to the speaker 122b( Figure 5 ) and the adder 260.

[0070] The adder 260 adds the signal of the frequency band below 2 kHz output from the adder 262 and gain-adjusted to the component of the frequency band above 2 kHz output from the BPF 240. The added signal is input to the speaker 122a( Figure 4 )

[0071] If the SP driving unit 130A having such a configuration is input with an audio sound signal, it inputs the signal with all the frequency components included in the audio sound signal gain-adjusted to the speaker 122a( Figure 4 ), inputs the signal with each frequency component below 2 kHz and gain-adjusted to the speakers 122a and 122b( Figure 5 ), inputs the signal with each frequency component below 1 kHz and gain-adjusted to the speakers 122a, 122b, and 122c( Figure 6 ), inputs the signal with each frequency component below 500 Hz and gain-adjusted to the speakers 122a, 122b, 122c, and 122d( Figure 7 ), thereby driving each speaker 122 included in the speaker 120. In addition, in front of each speaker 122, there is an amplifier that amplifies the signal and drives each speaker 122, but it is omitted in Figure 8 . The above content is organized by each frequency band as follows.

[0072] (1b) The signal of the frequency component below 500 Hz included in the audio sound is extracted by the BPF264, and after being gain-adjusted by the filter 256, it is input to the speakers 122a to 122d. That is, the signal of the frequency component below 500 Hz is input to all the speakers 122 included in the area s4 of the speaker array 120 after being gain-adjusted for each frequency band. Regarding the sound of the frequency components radiated from each of the speakers 122a to 122d like this, the range of the directivity characteristic is set so that it reaches Figure 3 the three listeners M1 and M2 in the areas p1 and p2 shown.

[0073] (2b) The signal of the frequency component of 500 to 1 kHz included in the audio sound is extracted by the BPF244, and after being gain-adjusted by the filter 254, it is input to the speakers 122a to 122c. That is, the signal of the frequency component of 500 to 1 kHz is input only to the speakers 122a, 122b, and 122c included in the central area s3 of the speaker array 120 after being gain-adjusted for each frequency band. The sound of the frequency components radiated from a part of the speakers 122a to 122c like this has a narrower directivity characteristic of the radiated sound by an amount corresponding to the increase in frequency compared with the frequency component below 500 Hz, but by making the range where the speakers 122a, 122b, and 122c that radiate the sound smaller by a corresponding amount, the range of the directivity characteristic of the same degree as in the case of (1b) above is ensured.

[0074] (3b) The signal of the frequency component of 1 to 2 kHz included in the audio sound is extracted by the BPF242, and after being gain-adjusted by the filter 252, it is input to the speakers 122a and 122b. That is, the signal of the frequency component of 1 to 2 kHz is input only to the speakers 122a and 122b included in the central area s2 of the speaker array 120 after being gain-adjusted for each frequency band. The sound of the frequency components radiated from a part of the speakers 122a and 122b like this has a further narrower directivity characteristic of the radiated sound by an amount corresponding to the increase in frequency compared with the frequency component below 1 kHz, but by making the range where the speakers 122a and 122b that radiate the sound further smaller by a corresponding amount, the range of the directivity characteristic of the same degree as in the case of (1b) or (2b) above is ensured.

[0075] (4b) The signals of the frequency components above 2 kHz included in the audio sound are directly input to the speaker 122a. That is, the signals of the frequency components above 2 kHz are only input to the speaker 122a included in the central region s1 of the speaker array 120. The sound of the frequency components radiated from a part of the speakers 122a, compared with the frequency components below 2 kHz, has a more narrow radiation directivity characteristic corresponding to the amount of increase in frequency. However, by making the range where the speakers 122a radiating the sound is further reduced by a corresponding amount, a range of directivity characteristics similar to that in each of the cases (1b), (2b), and (3b) above is ensured.

[0076] In this way, in the speaker system 100A of this modification example, by using the filters 252, 254, and 256 to adjust the gain of each frequency band, when sounds are radiated from different numbers of speakers 122 corresponding to each frequency component, differences in the output levels of each frequency component can be eliminated.

[0077] Figure 9 It is a diagram showing the configuration of a speaker system of another modification example. Figure 9 The shown speaker system 100B is different from Figure 1 the shown speaker system 100 in that the SP drive unit 130 is replaced with the SP drive unit 130B, and the speaker array 120 is replaced with the speaker array 220.

[0078] The SP drive unit 130B inputs and drives each speaker 222 by inputting a signal obtained by extracting three different types of frequency components from the audio sound signal output from the audio sound output unit 110, amplifying them, to the corresponding speakers 222 (222a, 222b, 222c, 222d) within the speaker array 220.

[0079] For this purpose, the SP drive unit 130B includes three BPFs (band - pass filters) 340, 342, 344 and two adders 350, 352.

[0080] The BPF 340 extracts the high - frequency components from the audio sound signal. The signal of the high - frequency components is input to the speaker 222b included in the speaker array 220 and the adder 350. The BPF 342 extracts the intermediate - frequency components from the audio sound signal. The signal of the intermediate - frequency components is input to the speaker 222c included in the speaker array 220 and the adder 352. The BPF 344 extracts the low - frequency components from the audio sound signal. The signal of the low - frequency components is input to the speaker 222d included in the speaker array 220 and the adder 350.

[0081] 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 intermediate-frequency component output from the BPF 342. The added signal is input to the speaker 222a included in the speaker array 220.

[0082] If an audio sound signal is input to the SP driving unit 130B configured like this, the BPF 340 extracts the high-frequency component included in the audio sound signal and inputs it directly or via the adders 350 and 352 to the speakers 222a and 222b, the BPF 342 extracts the intermediate-frequency component included in the audio sound signal and inputs it directly or via the adder 352 to the speakers 222a and 222c, and the BPF 344 extracts the low-frequency component included in the audio sound signal and inputs it directly or via the adder 350 to the speakers 222a and 222d, thereby driving each speaker 222 included in the speaker array 220. In addition, in front of each speaker 222, there is an amplifier that amplifies the signal and drives each speaker 222, but it is omitted in Figure 9 The above content is sorted by each frequency band as follows.

[0083] (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.

[0084] In this modification example, 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 (at a distance D1 from the central speaker 222a), the speaker 222c is arranged at an outer position (at a distance D2 (> D1) from the central speaker 222a), and the speaker 222d is arranged at an even more outer position (at a distance D3 (> D2) from the central speaker 222a).

[0085] In such a speaker array 220, the signal of the low-frequency component is input to the central speaker 222a and the outermost two end speakers 222d. Regarding the sound of the low-frequency component radiated from the speakers 222a and 222d arranged in the widest range like this, the range of the directivity characteristic is set so that it reaches Figure 3 the three listeners M1 and M2 located in the regions p1 and p2 as shown.

[0086] (2c) The signals of the intermediate-frequency components included in the audio sound are input to the speakers 222c and 222a of the speaker array 220. Compared with the sound of the low-frequency components, the sound of the intermediate-frequency components radiated from these speakers 222a and 222c has a narrower radiation sound directivity characteristic corresponding to the amount of increase in frequency. However, by reducing the location range of the speakers 222a and 222c that radiate the sound by a corresponding amount, a directivity characteristic range similar to that in the above case (1c) is ensured.

[0087] (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. Compared with the sound of the intermediate-frequency components, the sound of the high-frequency components radiated from these speakers 222a and 222b has a further narrower radiation sound directivity characteristic corresponding to the further increase in frequency. However, by further reducing the location range of the speakers 222a and 222b that radiate the sound by a corresponding amount, a directivity characteristic range similar to that in the above case (1c) or (2c) is ensured.

[0088] In addition, in this modification example, the number of speakers 222 that radiate the sound of each frequency band can be the same in all cases of the above (1c) to (3c). Therefore, there is no need to use Figure 8 filters such as the shown 252, 254, 256, etc., and the output level differences when radiating the sound of each frequency band are eliminated.

[0089] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be implemented within the scope of the gist of the present invention. In the Figures 4 - 7 shown speaker array 120, the number of speakers 122 in the vertical and horizontal directions is changed corresponding to the frequency components of the audio sound. However, as shown in Figure 3 , when switching the directivity characteristics of the respective frequency components of the radiation sound in one direction (horizontal direction), the number of speakers can be changed corresponding to this direction.

[0090] Figures 10 - 13 is a diagram showing another example of changing the number of speakers corresponding to the frequency band. It is assumed that the frequency band below 4 kHz is divided into four parts, and four regions are set within the speaker array 320, which is the same as the example shown in Figure 4 . The region s1 ( Figure 10 ) including a total of 32 speakers 322 in the two centralmost vertical columns corresponds to the highest frequency band (above 2 kHz). In addition, the region s2 ( Figure 11) corresponds to the second highest frequency band (1 kHz to 2 kHz). In addition, a region s3 including the region s2 and a total of 128 speakers 322 in two columns on each of the left and right sides surrounding the region s2 ( Figure 12 ) corresponds to the third highest frequency band (500 Hz to 1 kHz). Further, a region s4 including the region s3 and a total of 256 speakers 322 in four columns on each of the left and right sides surrounding the region s3 ( Figure 13 ) corresponds to the entire frequency band including the lowest frequency. In this way, by making the horizontal range in which the speakers 322 are arranged narrower by 1 / 2 times when the frequency is doubled, it is possible to make the width of the horizontal directivity characteristics of the radiated sound corresponding to each frequency band approximately match.

[0091] Figure 14 is a diagram showing another example of changing the number of speakers according to the frequency band. In Figures 10 - 13 the example shown, the speaker array 320 is constituted by a total of 256 speakers 322 in 16 columns in the horizontal and vertical directions, but the number of speakers 322 in the vertical direction can be changed, for example. In Figure 14 the example shown, the speaker array 320 is constituted by 1 column (16 speakers) of speakers 322 in the vertical direction. Figure 14 in (A) of Figure 14 in (B) of Figure 14 in (C) of Figure 14 in (D) of Figures 10 - 13 correspond to the same frequency bands respectively.

[0092] In addition, in Figure 9 the modified example shown, the number of speakers 222 corresponding to each frequency component is the same, but it is not necessarily required to be the same. In addition, in this case, gain adjustment such as that of the speaker system 100A shown in Figure 8 can also be performed according to this difference.

[0093] Industrial applicability:

[0094] As described above, according to the present invention, by switching different speakers to be driven for each frequency component, it is possible to adjust so that the directivity characteristics of the radiated sound, which become narrower as the frequency is higher when radiated from the same speaker, are widened, and a plurality of listeners located at a specific place can hear sounds in a wide frequency range from low to high.

Claims

1. A loudspeaker system, characterized in that, Comprising: An output sound generation mechanism that outputs a sound as an output object; A speaker array including a plurality of speakers; and A speaker driving mechanism that extracts a plurality of frequency components with different frequencies from the output sound of the output sound generation mechanism, and selectively drives one or more of the speakers through signals of each of the plurality of frequency components. The speaker system inputs each of the plurality of frequency components to one or more of the speakers corresponding to the width of the directivity characteristics of each of the plurality of frequency components.

2. The speaker system according to claim 1, wherein: The higher frequency components correspond to one or more of the speakers configured in a narrow range, and the lower frequency components correspond to a plurality of the speakers configured in a wide range.

3. The speaker system according to claim 2, wherein: The higher frequency components correspond to a small number of the speakers configured in the narrow range, and the lower frequency components correspond to a large number of the speakers configured in the wide range.

4. The loudspeaker system according to claim 1, characterized in that, Further comprising: A gain adjustment mechanism that adjusts 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 the speakers corresponding to each of the plurality of frequency components is set to be the same.

6. The speaker system according to claim 5, wherein: The higher frequency components correspond to the speakers configured in a narrow range, and the lower frequency components correspond to the speakers configured in a wide range.

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