Speaker system

Abstract

To reduce downward shifting of a position of a sound image of a middle-range sound in an on-vehicle speaker system comprising a woofer and a squawker disposed higher than the woofer in a vertical axis.SOLUTION: A speaker system 1A comprises a woofer WF, a squawker SC, a filter 111 and a filter 112. The woofer WF and the squawker SC are disposed on a front door of a vehicle. The squawker SC is positioned higher than the woofer WF in a vertical axis in a vertical direction. The filter 111 is a low-pass filter and disposed between an output terminal 20 of an amplification device 2 and the woofer WF. The filter 112 is a high-pass filter and disposed between the output terminal 20 and the squawker SC. A crossover frequency of frequency characteristics of an output system L1 including the filter 111 and the woofer WF and frequency characteristics of an output system L2 including the filter 112 and the squawker SC is 300 Hz or lower.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a speaker system, and more particularly to a speaker system mounted in a vehicle such as a passenger car. [Background technology]

[0002] A multi-way speaker system includes a channel dividing network that divides an input sound signal into frequency bands and dedicated individual speakers corresponding to each frequency band. Prior art documents related to multi-way speaker systems include Patent Document 1. Patent Document 1 describes dividing a sound signal into frequency bands using an even-order Butterworth filter or Linkwits-Riley filter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 4-67895 Summary of the Invention [Problem to be solved by the invention]

[0004] When configuring an in-vehicle three-way speaker system including a tweeter for reproducing high-frequency sounds, a squawker for reproducing mid-frequency sounds, and a woofer for reproducing low-frequency sounds, the woofer is typically placed below the door. The squawker is typically placed above the woofer on a vertical axis, such as above the door, so that the sound image obtained by the sound reproduced from the squawker is positioned at the ears of the vehicle passengers. In this speaker layout, problems occur if the frequency bands of the sounds reproduced by the woofer and the squawker are not appropriately allocated. For example, suppose a singing voice is reproduced in a speaker system in which sounds having frequency components of 300 Hz to 500 Hz are overlappingly allocated to the squawker and the woofer. Since the frequency band of singing voices is generally 400 Hz to 2 kHz, singing voices having frequencies of 500 Hz to 2 kHz are output only from the squawker. On the other hand, singing voices with frequencies lower than 500 Hz are output from both the squawker and the woofer. The sound image of a singing voice having frequency components between 500 Hz and 2 kHz is obtained only by the sound reproduced from the squawker, so the position of this sound image is at the position of the passenger's ears. On the other hand, the sound image of a singing voice having a frequency lower than 500 Hz is obtained by the sound reproduced from the squawker and the woofer, so this sound image is located between the squawker and the woofer. In other words, the sound image of a singing voice having a frequency lower than 500 Hz is shifted to a position lower than the position of the passenger's ears. Therefore, passengers in the vehicle feel an uncomfortable sensation as if the sound source positions are different for singing voices having frequency components between 500 Hz and 2 kHz and singing voices having frequency components lower than 500 Hz.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to solve the problem of reducing the downward shift of the sound image position of mid-range sounds in an in-vehicle speaker system that includes a first speaker responsible for reproducing low-range sounds and a second speaker that is positioned higher on the vertical axis than the first speaker and is responsible for reproducing mid-range sounds. [Means for solving the problem]

[0006] A speaker system according to one aspect of the present disclosure includes a first speaker, a second speaker, a first filter, and a second filter. The first speaker and the second speaker are disposed in a vehicle equipped with the speaker system. The second speaker is positioned higher than the first speaker on a vertical axis along a vertical direction. The first filter is disposed between the first speaker and an output terminal of an amplifier that outputs a sound signal to the speaker system. The second speaker is disposed between the output terminal and the second speaker. The first filter is a low-pass filter. The second filter is a high-pass filter or a band-pass filter. In this speaker system, a crossover frequency between the frequency characteristics of a first output system including the first filter and the first speaker and the frequency characteristics of a second output system including the second filter and the second speaker is 300 Hz or less. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating an example configuration of a speaker system 1A according to an embodiment of the present disclosure. [Figure 2] 1 is a diagram showing an example of the arrangement of a woofer 31, a squawker 32A, and a tweeter 33 in a vehicle C equipped with a speaker system 1A. [Figure 3] FIG. 2 is a diagram illustrating an example of an equivalent circuit of a speaker. [Figure 4] FIG. 2 is a diagram illustrating an example of the configuration of a filter 111. [Figure 5] FIG. 2 illustrates an example of the configuration of a filter 112. [Figure 6] FIG. 1 is a diagram illustrating frequency characteristics of first-, second-, third-, and fourth-order low-pass filters. [Figure 7] 10 is a diagram illustrating an example of frequency characteristics of a filter 111, a filter 112, and a filter 113. FIG. [Figure 8] FIG. 1 is a diagram showing an example of the configuration of a conventional speaker system 1D. [Figure 9] 1 is a diagram showing an example of the configuration of a speaker system 1E in which the number of parts is reduced from that of a conventional speaker system 1D. [Figure 10]FIG. 10 is a diagram showing an example of the frequency characteristic of impedance in a speaker system 1E when the cutoff frequency of a filter 112 is set to 464 Hz. [Figure 11] 10 is a diagram showing an example of frequency characteristics of impedance in a speaker system 1A. FIG. [Figure 12] 10 is a diagram showing an example of measurement results of sound pressure for each frequency of sound reproduced in speaker system 1A. FIG. [Figure 13] FIG. 10 is a diagram showing an example of the configuration of a speaker system 1B according to a modified example (3). [Figure 14] FIG. 10 is a diagram showing an example of the configuration of a speaker system 1C according to a modified example (4). DETAILED DESCRIPTION OF THE INVENTION

[0008] A. Embodiment FIG. 1 is a diagram illustrating an example configuration of a speaker system 1A according to an embodiment of the present disclosure. The speaker system 1A is a three-way speaker system including a channel dividing network 10A, a woofer 31, a squawker 32A, and a tweeter 33. The woofer 31 is responsible for reproducing low-frequency sounds. The squawker 32A is responsible for reproducing mid-frequency sounds. The tweeter 33 is responsible for reproducing high-frequency sounds. Although FIG. 1 illustrates one woofer 31, one squawker 32A, and one tweeter 33, the speaker system 1A may include multiple pairs of speakers each consisting of a woofer 31, a squawker 32A, and a tweeter 33.

[0009] The speaker system 1A is an in-vehicle speaker system mounted in a vehicle. FIG. 2 is a diagram showing an example of the arrangement of the woofer 31, the squawker 32A, and the tweeter 33 in a vehicle C equipped with the speaker system 1A. In the vehicle C, the driver's seat is located on the right side and the passenger seat is located on the left side relative to the direction of travel. The vehicle C is used in Japan, India, the United Kingdom, Australia, African countries, etc. Note that the arrangement of the driver's seat and the passenger seat may be reversed. Such vehicles are used in China, Germany, France, Italy, the United States, etc. As shown in FIG. 2, the tweeter 33 is located on the console CS of the vehicle C, closer to the driver's seat than to the passenger seat. The woofer 31 and the squawker 32A are located on the front door D, which is closer to the driver's seat than to the passenger seat in the vehicle C. More specifically, the woofer 31 is located on the front door D, closer to the floor F than to the driver's seat surface SS. On the other hand, the squawker 32A is arranged in the front door D at a position closer to the pillar P than the seat surface SS of the driver's seat so that the position of the sound image obtained by the sound reproduced from the squawker 32A is at the ear position of a passenger sitting in the driver's seat. In other words, the squawker 32A is located higher on the vertical axis Z that extends vertically than the woofer 31 in the vehicle C. Note that in FIG. 2, the symbol TR indicates the trunk of the vehicle C. If the speaker system 1A includes another set of the woofer 31, the squawker 32A, and the tweeter 33, the other set of the woofer 31, the squawker 32A, and the tweeter 33 may be provided in the front door closer to the passenger seat than the driver's seat in the vehicle C, and in a position on the console CS closer to the passenger seat than the driver's seat.

[0010] In this embodiment, the impedance of each of the woofer 31, squawker 32A, and tweeter 33 is 4 Ω, the same as the impedance of a typical speaker. The impedance of each of the woofer 31, squawker 32A, and tweeter 33 is calculated by simulation based on the equivalent circuit shown in FIG. 3. FIG. 3 is a diagram showing an example of a speaker equivalent circuit. The inductance of inductor Le1 in FIG. 3 is a parameter corresponding to the inductance of the voice coil of the speaker, and the resistance value of resistor Re1 is a parameter corresponding to the DC resistance of the voice coil. The capacitance of capacitor Cms1, the inductance of inductor Lms1, and the resistance value of resistor Rms1 in FIG. 3 are parameters determined according to the cone, damper, and edge of the speaker.

[0011] 1 divides an audio signal Sin input to a speaker system 1A into a low-frequency audio signal S1, a mid-frequency audio signal S2, and a high-frequency audio signal S3. The audio signal S1 is supplied to a woofer 31. The audio signal S2 is supplied to a squawker 32A. The audio signal S3 is supplied to a tweeter 33.

[0012] FIG. 1 shows, in addition to a speaker system 1A, an amplifier 2 that supplies a sound signal Sin to the speaker system 1A. The amplifier 2 has an output terminal 20 that outputs the sound signal Sin. A channel dividing network 10A is connected to the output terminal 20. A sound signal is supplied to the amplifier 2 from an in-car audio device such as a CD (Compact Disk) player. In FIG. 1, the in-car audio device that supplies the sound signal to the amplifier 2 is not shown. The sound signal supplied from the in-car audio device to the amplifier 2 is, for example, a sound signal representing singing voice. The amplifier 2 amplifies the sound signal supplied from the in-car audio device. The amplifier 2 outputs the amplified sound signal as the sound signal Sin from the output terminal 20.

[0013] As shown in FIG. 1 , the channel dividing network 10A includes a filter 111, a filter 112, a filter 113, a resistor 121, and a resistor 122. In this embodiment, the resistance value of the resistor 121 is 0.5 Ω, and the resistance value of the resistor 122 is 1 Ω. The filter 111 and the resistor 121 are connected in series between the output terminal 20 of the amplifier device 2 and the woofer 31. The filter 111, the resistor 121, and the woofer 31 constitute an output system SL1 that outputs low-frequency sounds. The filter 112 and the resistor 122 are connected in series between the output terminal 20 and the squawker 32A. The filter 112, the resistor 122, and the squawker 32A constitute an output system SL2 that outputs mid-frequency sounds. The filter 113 is provided between the output terminal 20 and the tweeter 33. In this embodiment, the filter 113 and the tweeter 33 constitute an output system SL3 that outputs high-frequency sounds.

[0014] The filter 111 is a low-pass filter. In this embodiment, the cutoff frequency of the filter 111 is set to 288 Hz. The filter 111 generates a sound signal S1 by attenuating frequency components having frequencies higher than 288 Hz in the sound signal Sin supplied from the amplifier device 2. The cutoff frequency is the boundary frequency between the pass band and the stop band of the filter. More specifically, the cutoff frequency is the frequency at which the attenuation of the output signal of the filter relative to the input signal is 3 dB.

[0015] The filter 112 is a high-pass filter. In this embodiment, the cutoff frequency of the filter 112 is set to 276 Hz. The filter 112 generates a sound signal S2 by attenuating frequency components having a frequency lower than 276 Hz in the sound signal Sin supplied from the amplifier device 2. The filter 113 is a high-pass filter like the filter 112. In this embodiment, the cutoff frequency of the filter 113 is set to 9.8 kHz. The filter 113 generates a sound signal S3 by attenuating frequency components having a frequency lower than 9.8 kHz in the sound signal Sin supplied from the amplifier device 2.

[0016] In this embodiment, the cutoff frequency of filter 111 is 288 Hz, but the cutoff frequency of filter 111 is not limited to 288 Hz as long as it is 300 Hz or less. If the cutoff frequency of filter 111 is set higher than 300 Hz, sounds with frequencies around 300 Hz are output from woofer 31 at high sound pressure. In this embodiment, sounds in a frequency band equal to or higher than 300 Hz are mainly output from squawker 32A. If the cutoff frequency of filter 111 is set higher than 300 Hz, sounds with frequencies around 300 Hz are output from woofer 31. As a result, the position of the sound image of sounds with frequencies around 300 Hz shifts downward on vertical axis Z from the position of the ears of a passenger sitting in the driver's seat. Therefore, in order to reduce the downward shift of the position of the sound image of sounds with frequencies around 300 Hz, it is preferable that the cutoff frequency of filter 111 be 300 Hz or less.

[0017] FIG. 4 is a diagram showing an example of the configuration of filter 111. In addition to filter 111, FIG. 4 also shows an amplifier 2, a resistor 121, and a woofer 31. As shown in FIG. 4, filter 111 is a second-order low-pass filter composed of an inductor L1 and a capacitor C1. FIG. 5 is a diagram showing an example of the configuration of filter 112. In addition to filter 112, FIG. 5 also shows an amplifier 2, a resistor 122, and a squawker 32A. As shown in FIG. 5, filter 112 is a first-order high-pass filter composed only of capacitor C2. Filter 113 is also a first-order high-pass filter, like filter 112.

[0018] FIG. 6 shows the frequency characteristics of first-, second-, third-, and fourth-order low-pass filters. In FIG. 6, FC indicates the cutoff frequency. FL indicates the lower limit frequency of a one-octave frequency band centered on the cutoff frequency, and FH indicates the upper limit frequency of that frequency band. The frequency characteristics of first-, second-, third-, and fourth-order high-pass filters can be obtained by horizontally inverting the frequency characteristics shown in FIG. 6 around the cutoff frequency. As shown in FIG. 6, higher-order filters have steeper attenuation in the stopband than lower-order filters. Furthermore, higher-order filters have a greater number of passive elements than lower-order filters.

[0019] Generally, a woofer can output sound up to 4 kHz, so to reduce the downward shift of the sound image of the sound reproduced by the squawker 32A from the position of the passenger's ears, it is desirable that the attenuation in the stop band of the filter 111 be steep. This is because it is preferable that the frequency band of the sound reproduced from the squawker 32A and the frequency band of the sound reproduced from the woofer 31 do not overlap. For this reason, in this embodiment, a second-order low-pass filter is used as the filter 111. A second-order low-pass filter has steeper attenuation in the stop band than a first-order low-pass filter.

[0020] On the other hand, because filter 112 is a first-order high-pass filter, sound signal S2 output from filter 112 may contain signal components of frequencies lower than the cutoff frequency of filter 112 without being sufficiently attenuated. As a result, interference may occur between the sound reproduced from woofer 31 and the sound reproduced from squawker 32A in the frequency band lower than the cutoff frequency of filter 112. However, the sound reproduced from squawker 32A is generally attenuated in the frequency band lower than 200 Hz. Furthermore, because the frequency band lower than 200 Hz is lower than 400 Hz, which is the lower limit of the singing voice band, there is no particular effect on the sound quality of the singing voice reproduced by speaker system 1A.

[0021] Furthermore, in this embodiment, since filter 112 and filter 113 are both first-order high-pass filters, interference may occur between the sound reproduced from squawker 32A and the sound reproduced from tweeter 33. However, in the frequency band where the sound reproduced from squawker 32A and the sound reproduced from tweeter 33 overlap, the frequency is sufficiently high and the effect of phase interference is small, so no particular problem occurs.

[0022] 7 shows a graph G1 of the frequency characteristics of the filter 111, a graph G2 of the frequency characteristics of the filter 112, and a graph G3 of the frequency characteristics of the filter 113. The crossover frequency between the frequency characteristics of the output system SL1 and the frequency characteristics of the output system SL2 is determined according to an intersection P1 between the graphs G1 and G2. The crossover frequency between the frequency characteristics of the output system SL1 and the frequency characteristics of the output system SL2 refers to the frequency at which the frequency characteristics of the output system SL1 and the frequency characteristics of the output system SL2 intersect. In this embodiment, in order to set this crossover frequency to 300 Hz or less, the cutoff frequency of the filter 112 is set to 276 Hz.

[0023] Before describing the effects of this embodiment, a conventional 3-way speaker system will be described for comparison. FIG. 8 is a diagram showing a configuration example of a speaker system 1D, which is an example of a conventional 3-way speaker system. Comparing the speaker system 1D with the speaker system 1A, the speaker system 1D differs from the speaker system 1A in that the speaker system 1D includes a channel dividing network 10D instead of the channel dividing network 10A. The channel dividing network 10D differs from the channel dividing network 10A in the following three points. The first difference is that a second-order high-pass filter 133 is used to generate the sound signal S3. The second difference is that a band-pass filter 132 is used to generate the sound signal S2. The band-pass filter 132 is configured by connecting a second-order high-pass filter and a second-order low-pass filter in series. The third difference is that the speaker system 1D does not include resistors 121 and 122.

[0024] When a 3-way speaker system is installed in a vehicle C, it is necessary to reduce the number of components constituting the speaker system. To reduce the number of components in a conventional speaker system 1D, it is possible to replace the high-pass filter 133 with a filter 113 and the band-pass filter 132 with a filter 112, as in a speaker system 1E shown in FIG. 9 . Replacing the high-pass filter 133 with the filter 113 eliminates one inductor, and replacing the band-pass filter 132 with the filter 112 eliminates the low-pass filter and another inductor. As mentioned above, using a first-order high-pass filter to generate the sound signal S3 and a first-order high-pass filter to generate the sound signal S2 does not pose any particular problems in terms of sound quality. Comparing FIG. 9 with FIG. 1 clearly shows that the channel dividing network 10E in the speaker system 1E differs from the channel dividing network 10A in that it does not include resistors 121 and 122.

[0025] However, in the speaker system 1E shown in FIG. 9, the cutoff frequency of filter 112 needs to be set to a frequency sufficiently higher than the cutoff frequency of filter 111. The reason is as follows: In the speaker system 1E, when the cutoff frequencies of filter 112 and filter 111 are substantially equal, sound signals of frequencies near the cutoff frequency are supplied to woofer 31 and squawker 32A. Because filter 112 is a first-order high-pass filter, at frequencies near the cutoff frequency, squawker 32A is equivalently connected in parallel to woofer 31. When woofer 31 and squawker 32A are connected in parallel to amplifier 2, the combined impedance is lower than the impedance of woofer 31 alone or squawker 32A alone. As the impedance drops, there is a risk of an overcurrent occurring in amplifier 2. In order to reduce the occurrence of such an overcurrent, it is necessary to set the cutoff frequency of filter 112 in speaker system 1E to be sufficiently higher than the cutoff frequency of filter 111.

[0026] Fig. 10 is a diagram showing an example of the frequency characteristics of the impedance of speaker system 1E viewed from output terminal 20 when filter 111 has a cutoff frequency of 288 Hz and filter 112 has a cutoff frequency of 464 Hz. In the example shown in Fig. 10, the impedance in the frequency band of 200 to 500 Hz is sufficiently higher than the impedance of woofer 31 alone or squawker 32A alone, which is 4 Ω, and the flow of overcurrent in amplifier device 2 in this frequency band is reduced.

[0027] However, in speaker system 1E, if the cutoff frequency of filter 112 is set sufficiently higher than the cutoff frequency of filter 111, the connection between the frequency band of the sound output from squawker 32A and the frequency band of the sound output from woofer 31 will be poor, resulting in problems with sound quality. Resistors 121 and 122 in speaker system 1A are provided to prevent the above-mentioned overcurrent from occurring even if the cutoff frequency of filter 112 is set to a value approximately equal to the cutoff frequency of filter 111. FIG. 11 shows an example of the frequency characteristics of impedance in speaker system 1A. In the example shown in FIG. A10, the impedance in the frequency band of 200 to 500 Hz is sufficiently higher than the impedance of 4 Ω of the woofer 31 alone or the squawker 32A alone. Therefore, the flow of overcurrent through amplifier 2 in this frequency band is reduced.

[0028] FIG. 12 is a diagram showing an example of measurement results of sound pressure for each frequency of sound reproduced by speaker system 1A in the cabin of vehicle C. In FIG. 12, graph GW shows measurement results for sound reproduced by woofer 31 alone. In FIG. 12, graph GS shows measurement results for sound reproduced by squawker 32A alone. In FIG. 12, graph GT shows measurement results for sound reproduced by tweeter 33 alone. In FIG. 12, graphs GA1 and GA2 show measurement results for sound obtained by overlapping the sounds reproduced by woofer 31, squawker 32A, and tweeter 33. More specifically, graph GA1 shows measurement results when the sounds reproduced by woofer 31 and squawker 32A are in phase, and graph GA2 shows measurement results when the sounds reproduced by woofer 31 and squawker 32A are out of phase with each other. As is clear from the graphs GA1 and GA2 shown in Figure 12, there are no frequency bands in which the sound pressure of the sound reproduced by the speaker system 1A drops significantly, so the sound quality does not deteriorate significantly in any particular frequency band.

[0029] The speaker system 1A of this embodiment reduces downward shift of the sound image obtained by the sound reproduced from the squawker 32A. Furthermore, the speaker system 1A of this embodiment makes it possible to configure a 3-way speaker system with fewer components than conventional systems. Furthermore, this embodiment reduces overcurrent flow in the amplifier 2 while avoiding deterioration in sound quality due to poor connection between the frequency band of the sound output from the squawker 32A and the frequency band of the sound output from the woofer 31.

[0030] B. Deformation The above-described embodiment may be modified as follows. (1) In the speaker system 1A, the filter 112 is a high-pass filter, but the filter 112 may be a band-pass filter. However, since a band-pass filter is configured by connecting a high-pass filter and a low-pass filter in series, by using a high-pass filter as the filter 112 as in this embodiment, the number of components constituting the speaker system 1A can be reduced compared to an embodiment in which a band-pass filter is used as the filter 112.

[0031] (2) In speaker system 1A, filters 112 and 113 are both first-order filters, but either or both of filters 112 and 113 may be second-order filters. However, a second-order filter is made up of more components than a first-order filter. Therefore, by configuring both filters 112 and 113 as first-order filters, as in this embodiment, the number of components constituting speaker system 1A can be reduced compared to an embodiment in which either or both of filters 112 and 113 are second-order filters.

[0032] (3) In the speaker system 1A, the resistors 121 and 122 are provided to reduce the occurrence of overcurrent due to setting the cutoff frequency of the filter 112 to a value equivalent to the cutoff frequency of the filter 111. However, if the impedance of the squawker 32A is high, the resistor 122 is unnecessary. Furthermore, if the DC resistance component of the voice coil in the woofer 31 doubles as the resistor 121, the resistor 121 is unnecessary. In other words, the resistors 121 and 122 can be omitted. For example, the speaker system 1B shown in FIG. 13 differs from the speaker system 1A in that it does not include the resistors 121 and 122 and that a squawker 32B is provided instead of the squawker 32A. The impedance of the squawker 32B is adjusted to a value higher than that of a typical speaker, specifically, 5 Ω. In the speaker system 1B, the DC resistance component of the voice coil in the woofer 31 serves as the resistor 121.

[0033] (4) Speaker system 1A and speaker system 1B are examples of the application of the present disclosure to a 3-way in-vehicle speaker system. However, the application of the present disclosure is not limited to 3-way in-vehicle speaker systems, and the present disclosure may also be applied to a 2-way in-vehicle speaker system. FIG. 14 is a diagram showing an example configuration of speaker system 1C, which is an example of the application of the present disclosure to a 2-way in-vehicle speaker system consisting of a woofer 31 and a squawker 32. As is clear from comparing FIG. 14 with FIG. 13, speaker system 1C differs from speaker system 1B in the following two respects. The first difference is that speaker system 1C does not include a tweeter 33. The second difference is that speaker system 1C has a channel dividing network 10C instead of channel dividing network 10B. Channel dividing network 10C differs from channel dividing network 1B in that it does not include filter 113.

[0034] (5) In the above embodiment, the woofer 31 is disposed on the front door D, which is closer to the driver's seat than the passenger seat in the vehicle C. However, it may be disposed between the console CS and the floor F, or in the trunk TR of the vehicle C. The squawker 32A may also be disposed on a pillar P of the vehicle C. The pillar P is a column connecting the roof, which is a part of the roof, to the body. In short, the squawker 32A only needs to be positioned higher than the woofer 31 on the vertical axis Z along the vertical direction.

[0035] C. Aspects Understood from Each Embodiment and Modification The present disclosure is not limited to the above-described embodiments and modifications, and can be realized in various forms without departing from the spirit thereof. For example, the present disclosure can also be realized in the following forms. The technical features in the above embodiments corresponding to the technical features in each form described below can be replaced or combined as appropriate to solve some or all of the problems of the present disclosure or to achieve some or all of the effects of the present disclosure. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

[0036] A speaker system 1A according to one embodiment of the present disclosure includes a woofer 31, a squawker 32A, a filter 111, and a filter 112. The woofer 31 and the squawker 32A are disposed in a vehicle C that mounts the speaker system 1A. The woofer 31 is an example of a first speaker in the present disclosure. The squawker 32A is positioned higher than the woofer 31 along a vertical axis Z that extends in the vertical direction. The squawker 32A is an example of a second speaker in the present disclosure. The filter 111 is a low-pass filter. The filter 111 is disposed between the woofer 31 and an output terminal 20 of the amplifier 2 that outputs a sound signal Sin. The filter 111 and the woofer 31 constitute an output system SL1. The filter 111 is an example of a first filter in the present disclosure. The output system SL1 is an example of a first output system in the present disclosure. The filter 112 is a high-pass filter or a band-pass filter. The filter 112 is disposed between the output terminal 20 and the squawker 32A. The filter 112 and the squawker 32A constitute an output system SL2. The filter 112 is an example of a second filter in the present disclosure. The output system SL2 is an example of a second output system in the present disclosure. In this speaker system 1A, the crossover frequency between the frequency characteristics of the output system SL1 and the frequency characteristics of the output system SL2 is 300 Hz or less. The speaker system 1A reduces a downward shift in the position of the sound image obtained by the sound reproduced from the squawker 32A while avoiding deterioration in the sound quality of the sound reproduced by the woofer 31 and the squawker 32A. The woofer 31 may be disposed in the door, between the console and the floor, or in the trunk of the vehicle C, and the squawker may be disposed in the door or on a pillar of the vehicle C.

[0037] It is preferable that filter 112 is a high-pass filter. If filter 112 is a high-pass filter, the number of components constituting speaker system 1A can be reduced compared to when filter 112 is a band-pass filter.

[0038] The speaker system 1A may include a tweeter 33 and a filter 113 disposed between the output terminal 20 and the tweeter 33, and the filter 113 is preferably a high-pass filter. According to this embodiment, a 3-way speaker system can be constructed with fewer components than conventional systems while reducing downward shift of the sound image position. The tweeter 33 is an example of a third speaker in the present disclosure. The filter 113 is an example of a third filter in the present disclosure.

[0039] At least one of the filters 112 and 113 is preferably a first-order filter. According to this embodiment, the number of components constituting the speaker system 1A can be reduced compared to an embodiment in which both the filters 112 and 113 are second-order filters.

[0040] The speaker system 1A may further include at least one of a resistor 121 connected in series between the filter 111 and the woofer 31 and a resistor 122 connected in series between the filter 112 and the squawker 32A. The resistor 121 is an example of a first resistor in the present disclosure. The resistor 122 is an example of a second resistor in the present disclosure. According to this aspect, it is possible to prevent an overcurrent from flowing in the amplifier device 2 due to the crossover frequency between the frequency characteristics of the output system SL1 and the frequency characteristics of the output system SL2 being 300 Hz or less.

[0041] A squawker 32B having an impedance of 5 Ω or more may be used instead of the squawker 32A. This embodiment also makes it possible to prevent an overcurrent from flowing in the amplifier 2 due to the crossover frequency between the frequency characteristics of the output system SL1 and the frequency characteristics of the output system SL2 being 300 Hz or less. [Explanation of symbols]

[0042] 1A, 1B, 1C, 1D, 1E...speaker system, 10A, 10B, 10C, 10D, 10E...channel dividing network, 111, 112, 113...filter, 121, 122...resistor, 2...amplifier, 20...output terminal, 31...woofer, 32A, 32B...squawka, 33...tweeter.

Claims

1. a first speaker that is arranged in the vehicle and is not responsible for reproducing singing voices; a second speaker that is disposed in the vehicle and is located above the first speaker on a vertical axis along a vertical direction, and that is responsible for reproducing a singing voice; a first filter disposed between an output terminal of an amplifier that outputs a singing voice signal and the first speaker; a second filter disposed between the output terminal and the second speaker; the first filter is a second-order low-pass filter, the second filter is a high-pass filter or a band-pass filter, a crossover frequency between a frequency characteristic of a first output system including the first filter and the first speaker and a frequency characteristic of a second output system including the second filter and the second speaker is around 300 Hz; Speaker system.

2. 2. The speaker system of claim 1, wherein the second filter is a high-pass filter.

3. A third speaker; a third filter disposed between the output terminal and the third speaker; 3. The speaker system according to claim 2, wherein the third filter is a high-pass filter.

4. 4. The speaker system according to claim 3, wherein at least one of the second filter and the third filter is a first-order filter.

5. 5. The speaker system according to claim 1, further comprising at least one of a first resistor connected in series between the first filter and the first speaker, and a second resistor connected in series between the second filter and the second speaker.

6. 5. The speaker system according to claim 1, wherein the second speaker has an impedance of 5[Omega] or more.

7. the first speaker is disposed in a door, between a console and a floor, or in a trunk of the vehicle; The speaker system according to claim 1 , wherein the second speaker is disposed in the door or a pillar of the vehicle.

Images