WO2020129581A1

WO2020129581A1 - Onboard audio device

Info

Publication number: WO2020129581A1
Application number: PCT/JP2019/046951
Authority: WO
Inventors: 本地　由和; 克也平野
Original assignee: ヤマハ株式会社
Priority date: 2018-12-20
Filing date: 2019-12-02
Publication date: 2020-06-25
Also published as: JP2020102702A

Abstract

This onboard audio device includes a plurality of first speakers provided to a front section of a vehicle interior, at least one second speaker provided lower than the plurality of first speakers in the vehicle interior, and a processing unit that outputs to each of the plurality of first speakers a signal generated by filtering an input signal through a high-pass filter having a first cutoff frequency, and outputs to the at least one second speaker a signal generated by filtering the input signal through a low-pass filter having a second cutoff frequency.

Description

Car audio system

The present disclosure relates to an in-vehicle audio device.

　An audio device that reproduces sound in the passenger compartment requires listeners in the seat to hear the appropriate sound. Therefore, for example, there is known a technique in which a main speaker is provided corresponding to each seat and a woofer is provided at a position shared by a plurality of seats (see, for example, Patent Document 1).

JP 2012-10094 A

However, the above technology may impair the stereo localization.

An in-vehicle audio device according to an aspect of the present disclosure includes a plurality of first speakers provided in a front portion of a vehicle compartment and at least one second speaker provided below the plurality of first speakers in the vehicle compartment. A speaker and a signal generated by filtering the input signal with a high-pass filter having a first cutoff frequency are output to each of the plurality of first speakers, and the input signal is output to the second cutoff. A processing unit that outputs a signal generated by filtering with a low-pass filter having a frequency to the at least one second speaker.

An in-vehicle audio device according to an aspect of the present disclosure includes a plurality of first speakers provided in a range from a middle portion of a vehicle interior to a rear portion of the vehicle interior, and a plurality of first speakers below the first speakers in the vehicle interior. And outputting a signal generated by filtering an input signal with a high-pass filter having a first cutoff frequency to each of the plurality of first speakers, the at least one second speaker being provided in A processing unit that outputs a signal generated by filtering an input signal with a low-pass filter having a second cutoff frequency to the at least one second speaker.

It is a block diagram which shows the structure of the audio device which concerns on 1st Embodiment. It is a figure which shows the frequency characteristic of HPF and LPF in an audio device. It is a top view which shows arrangement|positioning of the speaker in an audio device. It is a figure which shows the characteristic of the reproduction frequency in an audio device. It is a figure which shows another example of arrangement|positioning of the woofer in an audio device. It is a figure which shows another example of arrangement|positioning of the woofer in an audio device. It is a block diagram which shows the structure of the audio device which concerns on 2nd Embodiment. It is a top view which shows arrangement|positioning of the speaker in an audio device. It is a block diagram which shows the structure of the audio device which concerns on 3rd Embodiment. It is a top view which shows arrangement|positioning of the speaker in an audio device. It is a figure which shows the preferable installation example of a speaker. It is a figure which shows the preferable installation example of a speaker.

An audio device according to an embodiment of the present disclosure will be described with reference to the drawings.
The audio device according to the embodiment is mounted on a vehicle such as a passenger car. Several embodiments are envisioned for this audio device. First, the audio device according to the first embodiment will be described.

<First Embodiment>
FIG. 1 is a block diagram showing an electrical configuration of the audio device 10a according to the first embodiment. The audio device 10a includes a head unit 100, a plurality of speakers, and a plurality of woofers. The plurality of speakers includes speakers 12FL, 12FR, 12RL and 12RR. The plurality of woofers includes

woofers

14L and 14R. The head unit 100 includes a signal acquisition unit 110, a volume control unit 120, a processing unit 200, and an amplification unit (AMP) 130.

The signal acquisition unit 110 acquires a sound signal output from a sound source, that is, a sound signal indicating a sound to be output by the audio device 10a. The sound source is, for example, a compact disc player, a digital audio player or a smartphone. The sound signal is a stereo signal. The sound signal includes an L signal for the left channel and an R signal for the right channel. The signal acquisition unit 110 acquires a sound signal wirelessly or by wire. The sound signal is a digital signal or an analog signal. When the signal acquisition unit 110 is an acquisition unit that acquires an analog sound signal, the signal acquisition unit 110 includes a converter that converts the analog sound signal into a digital sound signal. The converter is used to facilitate signal processing on the sound signal. The signal acquisition unit 110 is, for example, a signal acquisition circuit.

The volume control unit 120 adjusts the amount of sound output from the audio device 10a according to a user's operation on a slider or a switch. The volume adjusting unit 120 generates an input signal input to the processing unit 200. The volume adjusting unit 120 specifically generates the input signal by adjusting the amplitude of the sound signal according to the user's operation on the slider or the switch. The input signal includes an L signal and an R signal. The volume control unit 120 is, for example, a volume control circuit.

The processing unit 200 is, for example, a DSP (Digital Signal Processor). The processing unit 200 includes an HPF (High Pass Filter) 210, an LPF (Low Pass Filter) 220, a plurality of delay units, a plurality of equalizers, and a plurality of effectors. The plurality of delay units include

delay devices

212F, 212R and 222. The plurality of equalizers includes

equalizers

214F, 214R and 224. The plurality of effectors includes

effectors

216F, 216R and 226.
The processing unit 200 may be realized by a microcomputer instead of the DSP. That is, some or all of the processing executed by the processing unit 200 can be realized by a DSP, a microcomputer, or the like.

FIG. 2 is a diagram showing the frequency characteristics of the HPF 210 and the LPF 220. The HPF 210 and the LPF 220 have a common cutoff frequency fc. The cutoff frequency fc is an example of the first cutoff frequency and the second cutoff frequency. The input signal may include the first component included in the frequency band below the cutoff frequency fc. The input signal may include the second component included in the frequency band equal to or higher than the cutoff frequency fc. The HPF 210 executes a first filtering process that attenuates the first component in the input signal. The LPF 220 executes a second filtering process that attenuates the second component in the input signal. Therefore, the cutoff frequency fc functions as a crossover frequency. In the present embodiment, the cutoff frequency fc is set to 200 Hz, the reason for which will be described later.

The HPF 210 generates the HL signal by performing the first filtering process on the L signal included in the input signal. The HPF 210 generates the HR signal by performing the first filtering process on the R signal included in the input signal. The LPF 220 generates the LL signal by performing the second filtering process on the L signal included in the input signal. The LPF 220 generates the LR signal by performing the second filtering process on the R signal included in the input signal. The HL signal is divided into an FL signal which is an L signal for front and an RL signal which is an L signal for rear. The HR signal is divided into an FR signal which is a front R signal and an RR signal which is a rear R signal.

The description returns to FIG. The delay device 212F delays the FL signal to generate a delayed FL signal. The delay device 212F delays the FR signal to generate a delayed FR signal. The equalizer 214F generates the adjusted FL signal by adjusting the frequency characteristic of the delayed FL signal. The equalizer 214F generates the adjusted FR signal by adjusting the frequency characteristic of the delayed FR signal. The delay device 212R delays the RL signal to generate a delayed RL signal. The delay device 212R delays the RR signal to generate a delayed RR signal. The equalizer 214R adjusts the frequency characteristic of the delayed RL signal to generate the adjusted RL signal. The equalizer 214R generates the adjusted RR signal by adjusting the frequency characteristic of the delayed RR signal. The delay device 222 generates a delayed L signal by delaying the LL signal. The delay device 222 delays the LR signal to generate a delayed R signal. The equalizer 224 generates the adjusted L signal by adjusting the frequency characteristic of the delayed L signal. The equalizer 224 generates the adjusted R signal by adjusting the frequency characteristic of the delayed R signal.
Each of the

delay devices

212F, 212R, and 222 can adjust the delay amount based on the operation by the user in order to appropriately adjust at least one of the sound image localization and the sound quality. Each of the

equalizers

214F, 214R, and 224 is capable of adjusting the degree of frequency characteristic adjustment based on a user operation in order to appropriately adjust at least one of sound image localization and sound quality.

The effector 216F adds an effect such as reverb or echo selected by the user or the like to each of the adjusted FL signal and the adjusted FR signal. The effector 216R imparts the above-mentioned effect to each of the adjusted RL signal and the adjusted RR signal. The effector 226 imparts the above-mentioned effect to each of the adjustment L signal and the adjustment R signal.

The amplification unit 130 amplifies the output signal of the effector 216F, the output signal of the effector 216R, and the output signal of the effector 226. The output signal of the effector 216F specifically includes a front left (FL) channel signal and a front right (FR) channel signal. The output signal of the effector 216R specifically includes a rear left (RL) channel signal and a rear right (RR) channel signal. The output signal of the effector 226 specifically includes a low-frequency left channel signal and a low-frequency right channel signal. The amplification unit 130 amplifies each of the 6-channel signals.

Each of the speakers 12FL, 12FR, 12RL, and 12RR is a so-called full-range type speaker capable of reproducing sound in a range from low range to high range. Each of the speakers 12FL, 12FR, 12RL, and 12RR is an example of the first speaker. Each of the

woofers

14L and 14R is a speaker that reproduces a sound in a bass range. Each of the

woofers

14L and 14R is an example of the second speaker.

FIG. 3 is a plan view showing the arrangement of the speakers. Specifically, FIG. 3 is a plan view showing a vehicle 1a in which the audio device 10a is mounted.
The vehicle 1a is, for example, a right-hand drive vehicle and is a 4-door, 4- or 5-seater sedan. Specifically, the

doors

71 and 72 are located at the front of the vehicle 1a.

Doors

73 and 74 are located at the rear of the vehicle 1a. A driver seat 51 and a passenger seat 52 are provided at the front of the vehicle 1a.

Seats

53 and 54 are provided at the rear of the vehicle 1a. In the vehicle 1a, a steering wheel 22, an accelerator pedal 24, and a brake pedal 26 are provided at the front of the driver's seat 51.

The speakers 12FL and 12FR are provided in the front part of the vehicle 1a. The speakers 12RL and 12RR are provided in the rear part of the vehicle 1a. Specifically, the speakers 12FL and 12FR are provided on the dashboard 32, for example. The speaker 12FL is provided on the left portion of the dashboard 32 so as to output sound toward the center of the vehicle compartment, for example. The speaker 12FR is provided on the right portion of the dashboard 32 so as to output sound toward the center of the vehicle compartment, for example. The speakers 12RL and 12RR are provided, for example, in the upper part of the trunk room 34. The speaker 12RL is provided in the upper left part of the luggage compartment 34 so as to output sound toward the center of the passenger compartment, for example. The speaker 12RR is provided in the upper right part of the luggage compartment 34 so as to output sound toward the center of the passenger compartment, for example. The positions of the speakers 12FL and 12FR are substantially the same as the positions of the speakers 12RL and 12RR in the height direction.

The woofer 14L is provided, for example, in the left portion of the vehicle 1a and near the center in the front-rear direction of the vehicle compartment so as to output sound toward the center of the vehicle compartment. Specifically, the woofer 14L is provided at the rear part of the front left door 72, the front part of the rear left door 74, or the center pillar 36L. FIG. 3 shows an example in which the woofer 14L is provided on the center pillar 36L.
The woofer 14R is provided, for example, in the right portion of the vehicle 1a and near the center in the front-rear direction of the vehicle compartment so as to output sound toward the center of the vehicle compartment. Specifically, the woofer 14R is provided on the rear part of the front right door 71, the front part of the rear right door 73, or the center pillar 36R. FIG. 3 shows an example in which the woofer 14R is provided on the center pillar 36R.
Thus, the positions of the

woofers

14L and 14R are lower than the positions of the speakers 12FL, 12FR, 12RL and 12RR.

The head unit 100 is provided, for example, in the central portion of the instrument panel. The head unit 100 is connected to each of the speakers 12FL, 12FR, 12RL and 12RR via a wire harness. The head unit 100 is connected to each of the

woofers

14L and 14R via a wire harnel.

Each of the speakers 12FL, 12FR, 12RL, and 12RR receives the second component included in the frequency band of the cutoff frequency fc or higher of the input signal. Each of the speakers 12FL, 12FR, 12RL and 12RR outputs a sound based on the second component. Each of the

woofers

14L and 14R receives the first component included in the frequency band below the cutoff frequency fc of the input signal. Each of the

woofers

14L and 14R outputs a sound based on the first component.

<Cutoff frequency>
Here, the significance of the cutoff frequency fc of the HPF 210 and the LPF 220 will be described.
For convenience, it is assumed that the input signals are supplied to the full-range speakers 12FL, 12FR, 12RL, and 12RR without the

woofers

14L and 14R. In this configuration, setting of delay, equalizing, effect, etc. is not considered.

First, attention is paid to sounds emitted from each of the left speakers 12FL and 12RL. The sound emitted from each of the left speakers 12FL and 12RL is output toward the right side of the passenger compartment, and then reflected by the right end of the passenger compartment (mainly the right doors 71 and 73).
Therefore, in the vehicle interior, the sound output from each of the speakers 12FL and 12RL and the sound reflected by the right end of the vehicle interior are combined. Therefore, for a sound of a certain frequency, a standing wave (standing wave) having “nodes” at the left end and the right end of the passenger compartment is likely to occur.
When the vehicle width of the vehicle 1a is 1.7 m on average and the speed of sound is 340 m/s, the frequency of the standing wave in the vehicle compartment is 200 Hz in case of double vibration (1 wavelength). Actually, a standing wave is generated in the frequency band of about 200 to 250 Hz.

Generally, in an audio device, it is ideally desirable that the speaker is arranged so that sound is output from a high position in front of the user in all frequency bands. However, in reality, such an arrangement is difficult in a vehicle compartment where space is limited. The reason is as follows.
A speaker that plays a low frequency range of about 200 to 250 Hz in the reproduction frequency band requires a certain amount of aperture and volume. Therefore, it is difficult to freely lay out the speaker in the passenger compartment. For this reason, the above-mentioned speaker is often provided inside the door where it is easy to secure a certain volume.
As described above, in the general vehicle interior, the frequency band in which the standing wave is dominant is about 200 to 250 Hz. In this frequency band, it is particularly difficult to control localization even if the speaker arrangement is devised and various kinds of signal processing are used.
With a speaker that outputs sound over a wide frequency band below the frequency band where the standing wave is dominant, the sound image localization of an instrument whose main component is the sound in the frequency band below the frequency band where the standing wave is dominant It is very difficult to control. For example, the timbre of a bass instrument such as a bass drum or a bass has a component in a frequency band in which a standing wave is dominant. Therefore, the sound image localization varies depending on the frequencies of the components that make up the sound. This means that the sound image localization of one instrument is poor.
On the other hand, a speaker in which the upper end of the reproduction frequency band is higher than 250 Hz and the lower end of the reproduction frequency band is about 200 Hz can be downsized. Therefore, the degree of freedom in layout of such a speaker is high. Therefore, it is relatively easy to arrange such a speaker in an ideal place.
In addition, even in a low-pitched music instrument or the like, there is an auditory characteristic that the entire sound including a lower frequency is localized in a place where a sound in a frequency band of approximately 200 Hz or higher is reproduced.

For these reasons, the

woofers

14R and 14L, which require a certain amount of volume, have little influence on the sound image localization, and output sounds in the low range of less than approximately 200 Hz, are arranged below the vehicle 1a. Further, the speakers 12FL, 12FR, 12RL and 12RR that determine the sound image localization and that output the sound in the sound range of approximately 200 Hz or higher are disposed above the

woofers

14L and 14R and in ideal positions. With such an arrangement, it is possible to prevent the localization feeling from becoming unnatural.

In the present embodiment, as a specific process, the HPF 210 first cuts a component included in a frequency range of less than 200 Hz in the input signal. Subsequently, the output signal of the HPF 210 is supplied to each of the speakers 12FL, 12FR, 12RL and 12RR. For this reason, it is possible to arrange the miniaturized speakers 12FL, 12FR, 12RL, and 12RR at ideal positions while preventing the sense of localization from being unnatural due to the sitting position.
However, each of the speakers 12FL, 12FR, 12RL, and 12RR has almost no ability to reproduce low-frequency sounds. Therefore, in the present embodiment, the LPF 220 passes the component in the frequency range of less than 200 Hz, and the output signal of the LPF 220 is supplied to the

woofers

14L and 14R.
Therefore, according to the present embodiment, it is possible to eliminate the inconvenience of an unnatural localization feeling while securing the ability to reproduce low-frequency sounds.

The reproduction characteristics of this embodiment will be described with reference to FIG. As indicated by the broken line (1), in the configuration in which the woofer does not exist and the full-range type speaker exists, the sound pressure is insufficient in the low frequency range. On the other hand, as indicated by the alternate long and two short dashes line (2), the sound pressure is insufficient in the mid-high frequency range in the configuration in which the full-range type speaker does not exist and the woofer exists.
On the other hand, in the present embodiment, as shown by the solid line (3), the midrange and high range sounds are reproduced by the full-range type speakers (12FL, 12FR, 12RL and 12RR), and the low range sounds are reproduced by the woofer. (14L, 14R) is reproduced. Therefore, the sound pressure does not become insufficient in the low range.
In FIG. 4, the frequency on the horizontal axis is shown on a logarithmic scale.

Also, according to the present embodiment, it is possible to suppress the phenomenon that the sense of localization becomes unnatural. Therefore, a stable sense of localization can be obtained even if the seat layout of the vehicle 1a is changed. This example will be described later.

As mentioned above, in general, a woofer has a large caliber and a large volume in order to enhance its ability to reproduce low frequency sounds. For this reason, the woofer is arranged below the vehicle compartment where it is easy to secure an installation space. Even if the woofer is arranged in this way, the directivity of the sound in the low frequency range is low, so the sense of localization is not impaired.

<Cutoff frequency range>
The standing wave generated in the passenger compartment depends on the width of the passenger compartment (the length in the horizontal direction orthogonal to the traveling direction). If the width of the passenger compartment is in the range of 1.98 m to 1.45 m, specifically, if the width of the passenger compartment is from the maximum sedan to the light vehicle, the frequency of the standing wave (double Vibration) spans the range of 172 Hz to 234 Hz.
The frequency of the standing wave is in the range of 86 Hz to 117 Hz, which is half of 172 Hz to 234 Hz, in the case of fundamental vibration (half wavelength). In addition, the speed of sound also changes depending on atmospheric pressure, temperature, humidity, and the like. The direction in which the standing wave is generated is not limited to the width direction of the vehicle and may be various. Therefore, the frequency range of the standing wave is wider than the above range.
Therefore, in consideration of these circumstances, the cutoff frequency fc is preferably set within the range of 80 Hz or more and less than 250 Hz.

<Other installation locations for full-range type speakers>
The full-range type speakers 12FL and 12FR may be provided at points other than the dashboard 32. For example, the speaker 12FL may be provided in the A pillar 37L and the speaker 12FR may be provided in the A pillar 37R.

Similarly, the speakers 12RL and 12RR may be provided at a position other than the trunk room 34. For example, as shown in FIG. 5, the speaker 12RL may be provided on the center pillar 36L, preferably above the center pillar 36L, so that the sound emission direction is toward the rear seat 53. Further, the speaker 12RR may be provided on the center pillar 36R, preferably above the center pillar 36R, so that the sound emission direction is directed to the rear seat 54.
Further, the speaker 12RL may be provided not on the center pillar 36L but on the upper part of the window frame of the door 74 or on the ceiling near the door 74. In this case, the speaker 12RR may be provided not on the center pillar 36R but on the upper part of the window frame of the door 73 or the ceiling near the door 73.

<Other location of woofer>
The woofer 14L (14R) may be provided in a component of the vehicle other than the center pillar 36L (36R). For example, the woofer 14L (14R) may be provided on the floor surface near the center pillar 36L (36R).

Further, for example, as shown in FIG. 5, the woofer 14L may be provided on the rear left door 74, and the woofer 14R may be provided on the rear right door 73. The woofer 14L may be provided on the front left door 72, and the woofer 14R may be provided on the front right door 71.

Further, as shown in FIG. 6, the woofer 14L may be provided in the seat 54 on the left side of the rear part so that the sound emission direction is, for example, toward the upper part of the vehicle compartment. Similarly, the woofer 14R may be provided on the seat 53 on the left side of the rear portion so that the sound emission direction is, for example, toward the upper side of the vehicle compartment.

<Minimum configuration>
From the perspective of ensuring the ability to reproduce low-frequency sounds, and preventing the localization of the sound range near a specific frequency from being unnatural depending on the seating position, a full-range speaker can be used in front of the vehicle. It is conceivable that not two in two parts and two in the rear of the vehicle, four in total, but two in either the front of the vehicle or the rear of the vehicle would suffice. Further, the sound emission direction of the full-range type speaker does not have to be toward the center of the passenger compartment, but it is considered sufficient if it is directed toward the seated listener.
Since the woofer has low directivity on the low frequency side, it is considered that one woofer is sufficient.
Therefore, the second and third embodiments in which two full-range type speakers and one woofer are used will be described next.

<Second Embodiment>
FIG. 7 is a block diagram showing an electrical configuration of the audio device 10b according to the second embodiment. The audio device 10b differs from the audio device 10a shown in FIG. 1 in the following points. The first point is that the audio device 10b does not have a system for processing a signal for the rear. The second point is that the audio device 10b has an adder 230. The third point is that the system for processing the signal to the woofer is one channel in the audio device 10b.

The adder 230 outputs a signal generated by adding the L signal of the input signal and the R signal of the input signal. Therefore, the LPF 220, the delay device 222, the equalizer 224, and the effector 226 may perform the processing for one channel.

FIG. 8 is a plan view showing the arrangement of the speakers in the second embodiment. Specifically, FIG. 8 is a plan view of the vehicle 1b, similar to FIG. The speakers 12FL and 12FR are provided, but the speakers 12RL and 12RR are not provided. The woofer 14 is provided, for example, on the floor surface between the driver seat 51 and the passenger seat 52 so that the sound emission direction is, for example, toward the upper part of the vehicle compartment.
As described above, the directivity of the low frequency sound reproduced by the woofer 14 is low. Therefore, the woofer 14 does not necessarily have to be provided in the center of the vehicle compartment. For example, the woofer 14 may be provided near the left side of the vehicle or near the right side of the vehicle. The woofer 14 may be provided near the

rear seat

53 or 54. The woofer 14 may be provided on the seat surface instead of the floor surface. The woofer 14 may be provided on the

center pillar

36R or 36L.

According to the second embodiment, it is possible to achieve the same effect as that of the first embodiment with fewer speakers. The effect similar to that of the first embodiment is that the ability to reproduce sounds in the low frequency range is ensured and the sense of localization in the frequency range near a specific frequency does not become unnatural due to the sitting position. Therefore, the second embodiment is advantageous in terms of cost reduction and weight reduction as compared with the first embodiment.

<Third Embodiment>
FIG. 9 is a block diagram showing an electrical configuration of the audio device 10c according to the third embodiment. The audio device 10c differs from the audio device 10a shown in FIG. 1 in the following points. The first point is that the audio device 10c has no system for processing front signals. The second point is that the audio device 10c has an adder 230. The third point is that the system for processing the signal to the woofer is one channel in the audio device 10c.

FIG. 10 is a plan view showing the arrangement of speakers in the third embodiment. Specifically, FIG. 10 is a plan view of the vehicle 1c, as in FIG. The speakers 12RL and 12RR are provided, but the speakers 12FL and 12FR are not provided.
In the third embodiment, the speakers 12RL and 12RR are provided at the position shown in FIG. 3 or the position shown in FIG. Note that in FIG. 10, for convenience of explanation, the speakers 12RL and 12RR are shown as if they are provided at both the position shown in FIG. 3 and the position shown in FIG. Actually, it is sufficient that the speakers 12RL and 12RR are provided in either position.
As described above, the speakers 12RL and 12RR are provided within the range from the middle portion in the vehicle interior, specifically, the

center pillars

36L and 36R to the rear portion including the trunk room 14 when viewed in the front-rear direction of the vehicle.
In addition, the woofer 14 is provided, for example, similarly to the second embodiment.

According to the third embodiment, it is possible to achieve the same effect as that of the first embodiment with less speakers, as in the second embodiment. Therefore, the third embodiment is also advantageous in terms of cost reduction and weight reduction as compared with the first embodiment.

<Other>
In recent years, so-called three-row seat vehicles have appeared. Therefore, a preferred installation example of the speakers 12FL, 12FR, 12RL and 12RR in such a vehicle will be described.

FIG. 11 is a diagram showing an example in which speakers 12FL, 12FR, 12RL, and 12RR are installed in a vehicle 1d having three rows of seats. The vehicle 1d has

front seats

51 and 52 and

rear seats

53 and 54, as well as

middle seats

55 and 56. The

middle seats

55 and 56 are oriented in the traveling direction in FIG. However, the orientation of the

middle seats

55 and 56 can be changed. If the orientation of the

middle seats

55 and 56 is changed, the

middle seats

55 and 56 face the rearward direction as shown in FIG.

As shown in FIGS. 11 and 12, the speakers 12FL and 12FR are provided at the same positions as in the first embodiment shown in FIG. 5 and the like. The speaker 12RL is provided on the left side of the vehicle so that, for example, the sound emission direction from the speaker 12RL is directed to the listener located in the

seat

56 or 55 regardless of the orientation of the

seat

56 and 55. The speaker 12RR is provided on the right side of the vehicle so that, for example, the sound emission direction from the speaker 12RR is directed toward the listener located in the

seat

56 or 55 regardless of the orientation of the

seat

56 and 55. The speakers 12RL and 12RR are preferably installed above the position of the listener, such as the ceiling or the top of the window frame of the door.
Although the woofer 14 (14L and 14R) is not shown in FIGS. 11 and 12, the woofer 14 does not include the

seats

53 and 54 at the rear of the accelerator pedal 24 when viewed in the front-rear direction of the vehicle. It is preferable to be provided in the areas up to.

As shown in FIG. 11, when the

middle seats

55 and 56 face in the traveling direction, the front-rear balance of the sounds produced by the speakers 12FL, 12FR, 12RL, and 12RR is closer to the front side of the vehicle compartment than to the rear side of the vehicle compartment. As shown in FIG. 12, when the

seats

55 and 56 in the middle portion are directed rearward, the front and rear balance of the sounds by the speakers 12FL, 12FR, 12RL and 12RR is more than that of the front side of the passenger compartment. It may be changed so that a large amount is distributed to the rear side of the passenger compartment.
According to the above-described embodiment and the like, the sense of localization does not become unnatural depending on the sitting position, so that even if the orientation of the

middle seats

55 and 56 changes, for example, the sense of localization for the listeners located in the seats is not impaired. ..

<Appendix>
From the above-described embodiments and the like, for example, the following aspects are understood.

<Aspect 1>
An audio device according to a preferred aspect 1 of the present disclosure includes a plurality of first speakers provided in a front portion of a vehicle compartment and at least one second speaker provided below the plurality of first speakers in the vehicle compartment. A speaker and a signal generated by filtering the input signal with a high-pass filter having a first cutoff frequency are output to each of the plurality of first speakers, and the input signal is output to the second cutoff. A processing unit that outputs a signal generated by filtering with a low-pass filter having a frequency to the at least one second speaker.
According to the first aspect, it is possible to secure the ability to reproduce low-frequency sounds, and prevent the sense of localization in the sound range near a specific frequency from becoming unnatural depending on the sitting position.

<Aspect 2>
An audio device according to aspect 2 includes a plurality of first speakers provided in a range from a middle portion of the vehicle interior to a rear portion of the vehicle interior, and at least a portion of the audio device provided below the plurality of first speakers in the vehicle interior. One second speaker and a signal generated by filtering the input signal with a high-pass filter having a first cutoff frequency are output to each of the plurality of first speakers, and the input signal is output to the first speaker. A processing unit that outputs a signal generated by filtering with a low-pass filter having a cutoff frequency of 2 toward the at least one second speaker.
According to the second aspect, it is possible to secure the ability to reproduce low-frequency sounds and prevent the sense of localization in the sound range near a specific frequency from becoming unnatural depending on the sitting position.

<Aspect 3>
An audio device according to aspect 3 is the audio device according to

aspect

1 or 2, wherein the at least one second speaker is provided within a range from an accelerator pedal to a rear seat in a plan view. According to the aspect 3, the degree of freedom of the position of the second speaker can be made higher than the degree of freedom of the position of the first speaker.

<Aspect 4>
A fourth aspect of the audio device is the audio device of the third aspect, wherein the at least one second speaker is provided in the rear seat. According to the aspect 3, the degree of freedom of the position of the second speaker can be made higher than the degree of freedom of the position of the first speaker.

<Aspect 5>
An audio device according to aspect 5 is the audio device according to aspect 3, in which the at least one second speaker is provided in a center pillar. According to the aspect 5, the second speaker is located between the front seat and the rear seat.

<Aspect 6>
An audio apparatus according to aspect 6 is the audio apparatus according to

aspect

1 or 2, wherein the predetermined cutoff frequency is 80 Hz or more and less than 250 Hz. According to the aspect 6, since the standing wave is less likely to be generated in the vehicle interior, it is possible to prevent the localization feeling in the sound range near the frequency of the standing wave from being unnatural.

1a, 1b, 1c... Vehicle, 12FL, 12FR, 12RL, 12RR... Speaker (first speaker), 14L, 14R... Woofer (second speaker), 24... Accelerator pedal, 32... Dashboard, 34... Trunk room, 36L, 36R... Center pillar, 53, 54... Seat (rear seat), 200... Processing part, 210... HPF, 220... LPF.

Claims

A plurality of first speakers provided in the front part of the passenger compartment,
At least one second speaker provided below the plurality of first speakers in the vehicle compartment;
A signal generated by filtering an input signal with a high-pass filter having a first cutoff frequency is output to each of the plurality of first speakers, and the input signal has a second cutoff frequency. A processing unit that outputs a signal generated by filtering with a low-pass filter to the at least one second speaker;
In-vehicle audio device including.
A plurality of first speakers provided within a range from the middle part of the vehicle interior to the rear part of the vehicle interior;
At least one second speaker provided below the plurality of first speakers in the vehicle compartment;
A signal generated by filtering an input signal with a high-pass filter having a first cutoff frequency is output to each of the plurality of first speakers, and the input signal has a second cutoff frequency. A processing unit that outputs a signal generated by filtering with a low-pass filter to the at least one second speaker;
In-vehicle audio device including.
The in-vehicle audio device according to claim 1, wherein the at least one second speaker is provided within a range from an accelerator pedal to a rear seat in a plan view.
The vehicle-mounted audio device according to claim 3, wherein the at least one second speaker is provided in the rear seat.
The in-vehicle audio device according to claim 3, wherein the at least one second speaker is provided in a center pillar.
The in-vehicle audio device according to claim 1, wherein at least one of the first cutoff frequency and the second cutoff frequency is 80 Hz or more and less than 250 Hz.
The vehicle-mounted audio device according to claim 1, wherein the first cutoff frequency is the same as the second cutoff frequency.
The vehicle-mounted audio device according to claim 1, wherein each of the plurality of first speakers is a full-range type speaker.
The vehicle-mounted audio device according to claim 1, wherein the at least one second speaker is a woofer.