JPH0725288

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DESCRIPTION JPH0725288
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the
configuration of an acoustic device mounted on a car or the like and a control method therefor.
[0002]
2. Description of the Related Art In the case of an audio device such as a stereo used in a car such
as a passenger car or a bus, in many cases, speakers are provided at the front and the rear of the
car. Then, the volume of the front and rear speakers is often adjusted according to the number of
passengers and preference.
[0003]
FIG. 17 shows an example of a power distribution circuit of a conventional on-vehicle acoustic
device and speaker system used for the above-described purpose. Since it is often used in stereo,
it is shown as a stereo circuit, but two sets of the same circuit are used. In the figure, 1 is an
amplifier for amplifying an audio signal, 2 is a front speaker for driving the amplified audio
signal (hereinafter referred to as front speaker or front speaker), 21 is a rear speaker (hereinafter
referred to as rear speaker or rear speaker) 3) are variable resistors capable of adjusting the
volume level difference between the front speakers 2 and the rear speakers 21 and are parafader variable resistors. Reference numeral 4 denotes a switch for disconnecting the circuit of the
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rear speaker 21 in order to switch between the front and rear side speaker output specifications
and the output specifications of only the front side speaker output.
[0004]
A switch 5 shorts both ends (indicated by # 1 and # 3 in the figure) of the para-fader variable
resistor 3. In the drawings, L and R indicate devices for left and right because the devices have
stereo specifications.
[0005]
By the way, the front speaker 2 is always used regardless of the size of the vehicle and the
preference of the vehicle driver because of the necessity of driving. However, the rear speaker 21
is often disconnected by the switch 4 depending on the preference of the rear seat passenger.
[0006]
Before describing the operation, the structure of the known para-fader variable resistor 3 will be
described with reference to FIGS. 18 and 19. FIG. 18 is a schematic structural view of a parafader variable resistor, and FIG. 19 is a characteristic diagram also showing the change in
resistance with respect to the rotation angle. In FIG. 18, reference numeral 10 denotes a portion
of a resistor, and reference numeral 20 denotes a portion of a metal plate.
[0007]
The para-fader variable resistor of FIG. 18 is provided with shorting pieces each having an angle
of approximately 100 degrees on both sides of the resistance portion having an angle of
approximately 100 degrees. And, as the sliders, two sliders forming an angle of about 100
degrees are connected to one on the electric circuit.
[0008]
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FIG. 18A shows a state where the slider is turned counterclockwise, FIG. 18B shows a center
position, and FIG. C shows a state turned clockwise. In the figure, # 1, # 2, and # 3 indicate
terminal numbers for convenience of explanation.
[0009]
In FIG. 19, 12 indicates the resistance between terminals # 1 and # 2, and 23 indicates the
resistance between terminals # 2 and # 3. As apparent from FIG. 19, when the rotation angle of
the parafader variable resistor 3 is at the center, terminals # 1, # 2, and # 3 are all 0 Ω, and turn
clockwise to between # 1 and # 2 The resistance value of is increased, but the resistance value
between # 2 and # 3 remains 0Ω. And when it turns counterclockwise, it becomes the same
characteristic only by replacing # 1 and # 3.
[0010]
The audio signal is amplified by the amplifier 1 to drive the speakers 2 and 21. In a state where
the switch 5 is always open, when it is desired to drive only the front speaker 2, the switch 4 is
turned off. Further, the front speaker 2 and the rear speaker 21 can be driven together with the
switch 4 in the ON state. When the switch 4 is turned on, the volume difference between the
speakers 2 and 21 can be adjusted by the fader volume 3.
[0011]
In addition, if the switch 5 is turned on, the volume of the front speaker 2 and the rear speaker
21 can be matched regardless of the adjustment position of the parafader type variable resistor
3, for example. The switch 5 is used as a necessary switch in an on-vehicle stereo device because
it has the advantage of being easy to balance even when it is almost impossible.
[0012]
In other words, the switches 4 and 5 are separate switches whose purpose of use is different, and
the timing of operating them is of course different.
[0013]
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By the way, when the balance of the volume of the front speaker and the rear speaker is changed
as described above, good sound quality may not be maintained.
FIG. 20 is a schematic block diagram showing a conventional audio device.
In FIG. 20, an audio signal from an amplifier 1 of an audio signal passes through a sound quality
/ sound field corrector 13, and is divided into a front signal 11a and a rear signal 11b, which are
input to front signal attenuation means 40 and rear signal attenuation means 50 respectively. Be
done. The output from the front signal attenuation means 40 is reproduced from the front
speaker 2 through the high pass filter 14a and the front signal amplification means 14b. The
output from the rear signal attenuation means 50 passes through the high pass filter 16a and the
rear middle high tone signal amplifying means 16b, and the rear middle high tone output 16c
reproduced with the rear middle high tone speaker 21H, the low pass filter 17a and the rear bass
signal amplification means 17b. It is divided into a rear bass output 17c reproduced by the rear
bass speaker 21L. The control of the front signal attenuation means 40 and the rear signal
attenuation means 50 is performed by the microcomputer 18, and each attenuation amount is
determined by the microcomputer 18 by the signal from the operation unit 19.
[0014]
When the operation unit 19 is operated to change the sound volume, the microcomputer 18
determines the attenuation amount according to the operation amount, and controls the
attenuation amount of the front signal attenuation means 40 and the rear signal attenuation
means 50. When the operation unit 19 is operated to change the back and forth balance, the
microcomputer 18 determines the back and forth attenuation amount according to the operation
amount, and the attenuation amount obtained by adding the attenuation amount due to the
volume operation and the attenuation amount due to the front and back balance Control each
damping means to be Therefore, when the rear side volume is reduced, the rear middle high tone
output 16c and the rear bass output 17c are similarly attenuated.
[0015]
Generally, a large-aperture speaker is required to reproduce bass, but it is difficult to arrange a
large-aperture speaker on the front side in a vehicle cabin, so sufficient bass can not be
reproduced from the front side, and rear A large-diameter speaker is placed on the side, and bass
is often played back from the rear.
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[0016]
Since the conventional in-vehicle acoustic apparatus is configured as described above, when the
switch 4 is turned off and only the front speaker is driven in the configuration shown in FIG. If it
is turned to the rear speaker maximum side, there is a problem that the sound from the front
speaker will not come out at all even if the main volume volume is raised, and in order to prevent
such a defect, switch 5 to short the fader volume. In the end, there was a problem that two
switches were needed.
[0017]
One of the objects of the present invention is to solve the above-mentioned problems. When
driving only the front side speaker, the fader volume is turned to the rear side only by switching
one switch. The purpose is to obtain a device that can make sound from the front speaker even
when set in the state.
[0018]
Also, in the conventional audio device shown in FIG. 20, when the volume on the rear side is
attenuated by operating the front / rear balance, that is, when sound is to be output from the
front side, the bass is not sufficiently reproduced and the bass is insufficient. Had the problem of
[0019]
Another object of the present invention is to solve the above-mentioned problems. Even if the
front / rear balance is operated to lower the volume on the rear side, the bass can be reproduced
sufficiently, and the sound quality balance is further improved. The purpose is to obtain an onvehicle acoustic device that can be kept optimum.
[0020]
According to a first aspect of the present invention, there is provided an audio apparatus in
which two speakers are used in a power fader circuit in which two speakers are driven in parallel
and only one speaker is used. One single-pole double-throw (also called single-circuit, twocontact) switch is used as a switch to switch the use case, and a para-fader variable resistor is
used for balance adjustment, and switching is made to use only one speaker At the same time,
the power supplied to the connected speaker is not changed by the position of the parafader
variable resistor.
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[0021]
An audio apparatus according to a second aspect of the present invention is a switch for
switching between the case where two speakers are used and the case where only one speaker is
used in a power fader circuit in which two speakers are driven in series connection. One singlepole double-throw switch is used, and a series fader variable resistor is used for balance
adjustment.
[0022]
The power fader circuit of the audio equipment according to the third aspect of the present
invention is a plurality of speakers in which any one or both of the two speakers used in the
means of the first and second aspects are connected in parallel. It is configured.
[0023]
According to a fourth aspect of the present invention, there is provided a control method of an
acoustic device in which an output signal of an amplifier is distributed to a plurality of speakers,
wherein an output signal of the amplifier is distributed to each speaker by distribution control
means. The control is performed, and the operation of disabling at least one speaker disconnects
the remaining speakers from the control of the distribution control means.
[0024]
A control method of an acoustic device according to a fifth aspect of the present invention is a
method of distributing the output of an amplifier to a plurality of speakers whose ones are
commonly connected, wherein one parafader variable resistance for adjusting the distribution
ratio And a single-pole double-throw switch are used to short-circuit both ends of the parafader
variable resistor by disconnecting at least one speaker.
[0025]
A control method of audio equipment according to a sixth aspect of the present invention is a
method of distributing the output of an amplifier to a plurality of loudspeakers connected in
series, which comprises one series fader variable resistor for adjusting the distribution ratio One
single-pole double-throw switch is used to disconnect the sliding terminal of this series fader
variable resistor by shorting at least one speaker.
[0026]
According to a seventh aspect of the present invention, in the control method of the fourth to
sixth aspects, at least a part of the plurality of speakers used is a plurality of speakers connected
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in parallel.
[0027]
According to the eighth to tenth aspects of the present invention, an on-vehicle acoustic
apparatus includes a bass speaker and a mid-high tone speaker on the rear side, and in each of
which a voice is reproduced through the attenuation means, the rear bass The output of the
signal attenuation means is input to the rear middle high tone signal attenuation means, and
when adjusting the volume, the attenuation amount of the front signal attenuation means and the
rear bass signal attenuation means is changed, and the volume on the rear side is reduced by
adjusting the front and back balance. In some cases, the amount of attenuation of the rear middle
high tone signal attenuation means can be mainly changed.
[0028]
According to an eleventh aspect of the present invention, an on-vehicle acoustic apparatus is
configured such that the attenuation factor of the rear middle high sound signal attenuation
means changes in proportion to the attenuation factor of the rear bass signal attenuation means.
[0029]
According to a twelfth aspect of the present invention, there is provided a vehicle-mounted
acoustic apparatus, wherein the amount of attenuation of the rear bass signal attenuation means
is controlled in accordance with the smaller amount of attenuation of the front signal attenuation
means and the rear middle treble signal attenuation means. A bass signal attenuation amount
control means is provided.
[0030]
When the left-right balance of a stereo signal is adjusted, the on-vehicle acoustic device
according to the thirteenth invention of the present invention, when decreasing the volume on
one side, includes front signal attenuation means on that side and a rear middle high-tone signal
on that side The amount of attenuation of the attenuation means is increased.
[0031]
In the power fader circuit of the in-vehicle audio apparatus according to the first, second and
third inventions, only one single-pole double-throw switch is used, so that the operation is
simplified and the number of wires is also reduced. It will be less.
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In addition, the conventional function that the balance between the front and rear speakers can
be easily obtained is not lost by using the central click with the variable resistor.
[0032]
In the power distribution method of the acoustic device according to the fourth to seventh
inventions, according to the first procedure, a single contact of the single pole double throw
switch disconnects or short-circuits the speaker for making no sound.
Further, since the variable resistor for adjusting the distribution ratio of the output is shorted or
disconnected by the other single contact of the switch in the second procedure, the operation is
simple and the number of wires can be reduced.
[0033]
Further, in the on-vehicle acoustic apparatus according to the eighth to thirteenth inventions,
since the bass is generally not directional, the sound image is localized forward if middle and
high tones are attenuated even if the bass is out from the rear side, and Because bass is played
from the rear side, there is no shortage of bass even if bass can not be played on the front side.
[0034]
Example 1
Hereinafter, an embodiment of the present invention will be described with reference to the
drawings.
The same reference numerals in the drawings indicate the same or corresponding parts.
In FIG. 1, reference numeral 6 denotes a single pole double throw switch, which is called a
speaker changeover switch.
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The circuits are connected as shown.
31 is a para-fader variable resistor with a middle point click.
[0035]
With the middle point click, when the variable resistor 31 is turned, it is possible to feel a
constant hit or shock in the hand at the center position, and even if you do not look at the knob
(not shown) of the variable resistor It is a mechanism that can be easily adjusted to the center
position while driving, and is known.
[0036]
The audio signal is amplified by the amplifier 1 to drive the speakers 2 and 21.
When the speaker selector switch 6 is set to the b side and the fader volume 31 is in the state of
B in FIG. 18 (center position), the output of the amplifier 1 is applied to the front side speaker 2
and the rear side speaker 21 I can hear it.
When the fader volume 31 is in the state shown in A of FIG. 18 (counterclockwise turn-off), the
output of the amplifier 1 can be applied as it is to the front side speaker 2 and sound can be
produced. Since the internal resistance of the fader volume 31 is connected in series, the output
of the rear speaker 21 can have a sufficient amount of attenuation.
(Now, assuming that the resistance value is 80Ω and the rear speaker 21 is 4Ω, it can be
attenuated by about 26 dB.
)
[0037]
When the fader volume 31 is in the state of C in FIG. 18 (clockwise turning), the output of the
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amplifier 1 can be applied to the rear speaker 21 as it is, and the sound can be produced. Since
the output of the front side speaker 2 is connected in series with the internal resistance of the
volume control 31, the output can take a sufficient attenuation amount for the same reason as
when the state of FIG.
[0038]
When the speaker changeover switch 6 is set to the a side, the resistance of the fader volume 31
is short-circuited, and the rear side speaker 21 and the amplifier 1 become open and can not be
driven.
On the other hand, the fader volume 31 can drive only the front side speaker 2 with a series
resistance of 0 Ω in any state of FIG.
That is, even if the fader volume 31 is turned to the rear side, sound can be produced from the
front side speaker 2.
[0039]
Example 2
Although the case of the para-fader system, that is, the case where the two speakers 2 and 21 are
apparently connected in parallel is described in the above embodiment, a series fader system
may be used.
That is, the second embodiment will be described.
In FIG. 2, reference numeral 8 denotes a series fader volume capable of adjusting the volume
level difference between the front side speaker 2 and the rear side speaker 21, and a center click
is provided like 31 in FIG. 1.
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The structure of the series fader volume is shown in FIG. 3 and its characteristic is shown in FIG.
[0040]
Series fader volumes are known and come in a variety of forms, but here the total rotation angle
is divided into three equal parts, low antibodies are provided only in the middle range, and both
sides are metal It is a piece.
And only one slider is provided.
For the sliding terminal # 2, the resistance between # 1 and # 3 is shown in FIG. 4 as the
characteristic 12 and the resistance between # 3 as the characteristic 23.
[0041]
When the speaker selector switch 6 is set to the b side and the fader volume 8 is in the state of B
in FIG. 3 (center position), the front side speaker 2 and the rear side speaker 21 are connected in
series, so the same volume Can be driven by When the fader volume 8 is in the state of A in FIG.
3 (counterclockwise turning), both ends of the front side speaker 2 are shorted, and a sufficient
amount of attenuation can be obtained.
[0042]
On the other hand, the rear side speaker 21 is connected in parallel with the internal resistance
value of the fader volume 8, but since the resistance value is sufficiently larger than the
resistance value of the rear side speaker 21, there is no sound attenuation. It is driven with the
output of. When the fader volume 8 is in the state of FIG. 3C (clockwise turning), both ends of the
rear side speaker 21 are shorted, and a sufficient amount of attenuation can be obtained. On the
other hand, the front side speaker 2 is connected in parallel with the internal resistance value of
the fader volume 8, but the front side speaker 2 is driven with the output of the amplifier 1 as it
is for the same reason as in the state of FIG. 3A.
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[0043]
When the speaker changeover switch 6 is set to the a side, the movable portion of the fader
volume 8 is in the open state and does not operate. At the same time, both ends of the rear side
speaker 21 are shorted and can not be driven. That is, even if the fader volume 8 is turned to the
rear side, sound can be produced from the front side speaker 2.
[0044]
Example 3 In the first and second inventions shown in FIGS. 1 and 2, the speaker 2 or the
speaker 21 has been described as one speaker.
[0045]
However, the speakers may be a plurality of speakers connected in parallel as shown in FIG. In
FIG. 5, reference numeral 211 denotes a woofer which receives, for example, a low range, 212 a
middle range speaker, 213 a high range tow eater, and 214 a filter for improving the high range
characteristic. Although FIG. 5 shows the front speaker 2, the same applies to the rear speaker
21.
[0046]
In principle, it may be used in series, but if each range is different, the frequency characteristic of
the impedance changes, and the distribution ratio to each speaker may change depending on the
frequency, which is not preferable.
[0047]
Example 4
The procedure of the output distribution method for a vehicle-mounted acoustic device according
to the fifth invention is shown in FIG. The present invention is a method used in the case where
speakers serving as a load are connected in parallel (referred to as para-fader). In FIG. 6, the
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following first and second procedures are performed simultaneously, but in st61, as a first
procedure, the circuit of the speaker that does not make sound is disconnected. Next, in the
second step, both ends of the variable resistor for adjusting the distribution ratio are shorted at
st62.
[0048]
Although st61 and st62 are described as being performed sequentially in time for convenience of
explanation, they are performed simultaneously by one operation of one switch.
[0049]
Example 5
FIG. 7 shows the procedure of the method of distributing the output of the on-vehicle acoustic
device according to the sixth invention. The present invention is a method used when a speaker
serving as a load is connected in series (referred to as a series fader).
[0050]
Although the following third and fourth procedures are performed simultaneously in FIG. 7, in st
71, as a third procedure, the circuit of the speaker that does not make sound is short-circuited.
Next, as a fourth procedure, the sliding terminal of the variable resistor for adjusting the
distribution ratio is disconnected at st72. Although st71 and st72 are described as being
performed sequentially in time for convenience of explanation, they are performed
simultaneously by one operation of one switch.
[0051]
Example 6 The speakers serving as loads when performing steps 1, 2, 3 and 4 in the fourth and
fifth embodiments are described as being independent of each other, but like the speakers 211,
212 and 213 shown in FIG. Each of the plurality of speakers may be connected in parallel.
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[0052]
Example 7 FIG. 8 is a block diagram showing Embodiment 7 of the present invention. In FIG. 8, 1
is an amplifier of an audio signal, 13 is a sound quality / sound field corrector, and the audio
signal is divided here into a front signal 11a and a rear signal 11b. The front signal 11a is input
to the front signal attenuator 40, and the rear signal 11b is input to the rear bass signal
attenuator 50L. The output of the front signal attenuation means 40 is outputted from the front
speaker 2 through the high pass filter 14a and the front signal amplification means 14b. The
output of the rear bass signal attenuation means 50L passes through the rear middle high tone
signal attenuation means 50H, passes through the high pass filter 16a and the rear middle
middle tone signal amplification means 16b, and the rear middle high tone output 16c is
reproduced from the rear middle high tone speaker 21H. A signal not passing through the treble
signal attenuation means 50H passes through the low pass filter 17a and the rear bass signal
amplification means 17b, and the rear bass output 17c is reproduced from the rear bass speaker
21L.
[0053]
A microcomputer 18 controls the front signal attenuation means 40, the rear bass signal
attenuation means 50L, and the rear middle high tone signal attenuation means 50H, according
to a signal from the operation unit 19 having a knob for adjusting the volume and the front /
rear balance. Control each damping means. It is the same as the prior art except that the rear
middle high tone signal attenuation means 50H is inserted between the rear bass signal
attenuation means 50L and the high pass filter 16a.
[0054]
FIG. 9 is a flow chart showing the volume control program stored in the memory of the
microcomputer 18. Here, AT1: Attenuation amount calculated from the position of the volume
knob of the operation unit 19 AT2: Attenuation amount calculated from the position of the fader
knob of the operation unit 19 (front-back balance): Attenuation amount RLVOL of the front signal
attenuation means Attenuation amount RHVOL of rear bass signal attenuation means:
Attenuation amount of rear middle high tone signal attenuation means. When the volume and the
front / rear balance are manipulated by the operation unit 19, first, at st91, the attenuation
amount AT1 due to the volume is calculated and stored. In st92, the attenuation amount AT2 due
to the front-rear balance is calculated and stored. At the next st93, it is determined whether the
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front or the rear is to be attenuated in the front / rear balance, and the flag is set (st94) or the
flag is cleared (st95) depending on whether the rear side is attenuated. In st96, the attenuation of
each channel is calculated.
[0055]
The details are as shown in st97 to st103. First, the amount of attenuation of the front signal
attenuation means is calculated at st97 to st99. If the flag is set, only the attenuation amount
AT1 by the volume is set, and if the flag is cleared, the attenuation amount AT1 by the volume
and the attenuation amount AT2 by the front / rear balance are the attenuation amount of the
front attenuation means. st100 to st103 calculate attenuation amounts of the rear bass signal
attenuation means and the rear middle high tone signal attenuation means. The attenuation of
the rear bass signal attenuation means is only the attenuation AT1 by the volume, and the
attenuation of the rear middle high tone attenuation means is the attenuation AT2 by the front /
rear balance to the attenuation of the rear middle treble signal attenuation means if the flag is
set. Becomes zero if the flag is cleared. When the amount of attenuation of each channel can be
calculated, data is output to each attenuation means at st104, and the amount of attenuation
changes.
[0056]
FIG. 11 is a characteristic diagram showing the amount of attenuation of each attenuation means
when the front-rear balance is manipulated. As can be seen from this figure, even if the front /
rear balance is changed, the attenuation amount of the rear bass signal attenuation means does
not change, so that even when the front / rear balance is operated, sufficient bass can be
reproduced.
[0057]
Example 8 Further, when the program of the microcomputer 18 is as shown in the flowchart of
FIG. 10, the change characteristic as shown in FIG. 12 is obtained. Here, AT2 = AT3 + AT4, AT3:
Attenuation amount of rear bass signal calculated from the position of the fade knob of the
operation unit 19 (front and rear balance) AT4: calculated from the position of the fade knob of
the operation unit 19 (front and rear balance) It is an attenuation amount of the rear middle high
tone signal. In this way, when operating the front / rear balance to attenuate the rear side, the
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attenuation amount AT4 of the rear middle high tone signal attenuation means increases, and
when the rear middle high tone is attenuated and the entire volume drops, the bass attenuation
amount Since it can be adjusted to the whole volume as AT3, it can hold a good sound quality.
[0058]
Example 9 The rear bass signal attenuation means 50L and the rear middle high tone signal
attenuation means 50H can also be configured by an electronic volume with a built-in fader
volume.
[0059]
Example 10 A tenth embodiment of the present invention is shown in FIG. In the figure, reference
numerals 41, 51H and 51L denote attenuation amount detection means for the front signal
attenuation means 40, rear middle high tone signal attenuation means 50H and rear bass signal
attenuation means 50L, and 42, 52H and 52L denote control means for the respective
attenuation means. The other configuration is the same as that shown in FIG.
[0060]
Next, the operation will be described. FIG. 14 is a characteristic diagram for explaining the
operation, in which the horizontal axis represents the attenuation factor of the rear bass signal
attenuation means 50L, and the vertical axis represents the attenuation factor of the rear middle
high tone signal attenuation means 50H.
[0061]
In FIG. 13, when adjusting the volume balance at the front and rear, when reducing the volume at
the rear, only the attenuation amount of the rear middle high-tone signal attenuation means 50H
is controlled. Then, when lowering the overall volume, the attenuation factor of the rear bass
signal attenuation unit 50L is increased by the attenuation amount detection unit 51L and the
control unit 52L, and the rear bass signal attenuation unit 50L is proportional to the change of
the attenuation factor of the rear bass signal attenuation unit 50L. The attenuation rate of the
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middle to high sound signal attenuation means 50H is changed by the attenuation amount
detection means 51H and the control means 52H.
[0062]
The change in characteristics at this time is as shown in FIG. At this time, in FIG. 14, the rear bass
signal attenuation factor and the rear middle high tone signal attenuation factor do not
necessarily correspond one to one. The reason is that, as described above, the rear middle high
tone signal attenuation means 50 may be controlled independently.
[0063]
When reducing the volume of the front, only the attenuation factor of the front signal attenuation
means 40 is increased.
[0064]
In order to apply to a stereo device (with left and right speakers), it is necessary to provide a rear
bass speaker (including an amplifier) on the left and right as well, but when the bass is less
directional, it is omitted and only one speaker is used There are many cases where it is difficult to
apply the one shown in FIG. 8 to a stereo device, but this problem does not occur because all the
attenuation means are independent in this embodiment.
[0065]
Example 11.
The circuit configuration of the eleventh embodiment is the same as that of FIG. 13, and its
operation characteristic is shown in FIG.
(A) of FIG. 16 shows the attenuation characteristic of the overall volume, and (B) of FIG. 16 shows
the change characteristic of the front and back balance. FIG. 16B is the same as FIG.
[0066]
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Now, when the front / rear balance setting is performed at point b in FIG. 16B, the front signal
attenuation amount and the rear middle high sound signal attenuation amount are set to the
levels indicated by b2 and b1 in the drawing. This level corresponds to the position of N% of the
overall volume adjustment position shown in FIG. 16A, and if the overall volume adjustment
position is changed from this position up or down, the front signal and the rear middle high tone
signal are respectively Increase or decrease in proportion to the adjustment level. Here, the rear
bass signal attenuation amount is adjusted in accordance with the smaller amount of front signal
attenuation and rear signal attenuation. In the case of FIG. 16A, the rear bass signal attenuation
changes in proportion to the front signal, but at this time, if the rear middle high tone signal is
higher in level, it changes in proportion to the rear middle high tone signal. This embodiment is
also easy to apply to a stereo device.
[0067]
Example 12. As mentioned above, the directivity of low-frequency sound is not so sharp, and
there is little contribution to the 3D reproduction sound felt by people. Therefore, even in a small
passenger car, even if it is a stereo reproduction device, bass speakers are not arranged in stereo.
There are many cases where you can get one. Moreover, at this time, a single speaker is rarely
installed at the center, and is set together with the left or right speakers. This embodiment is for
such an apparatus configuration.
[0068]
FIG. 15 is a block diagram of the twelfth embodiment. In the figure, reference numeral 22
denotes a diode for superposing and adding left and right rear signals. Although there is only one
pair of the low-pitch speaker 21L and the amplification means 17a and 17b, a pair of left and
right front speakers and rear middle high-pitched speakers are used. That is, 1, 2, 13, 14a, 14b,
16a, 16b, 16c, 21H, 40, 41, 42, 50L, 51L, 52L, 50H, 51H, 52H show the left system of stereo,
while The following is from the right lineage. 101 is an amplifier for audio signals, 113 is sound
quality / sound field correction means, 140 is front signal attenuation means, 150H is rear
middle high tone signal attenuation means, 141 and 151H are front signal attenuation means
140, rear middle high tone signal attenuation means 150H Attenuation amount detection means
142, 152H are control means of each attenuation means, 114a is a high pass filter, 114b is a
front signal amplification means, 102 is a front speaker, 116a is a high pass filter, 116b is a rear
middle high sound signal amplification means, 121 H is a rear middle high-pitched speaker. Now,
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to lower the overall volume, all attenuation amounts of the left and right front attenuation means
40 and 140, the left and right rear middle high tone signal attenuation means 50H and 150H,
and the left and right common rear bass signal attenuation means 50L are increased.
[0069]
Then, when adjusting the balance of the left and right volume, for example, when reducing the
right volume, the attenuation amount of the right front attenuation means 140 and the right rear
middle high tone signal attenuation means 150H is increased, but the rear bass signal
attenuation means The attenuation of 50 L is not changed.
[0070]
As described above, according to the present invention, even if the front and rear speaker output
specifications are switched to the output specifications of the front speaker output only by
switching the switch, and the fader volume is manipulated, The configuration is such that the
power supplied to one connected speaker does not change, so even if the fader volume is turned
to the rear side, the sound can be emitted from the front side speaker, and the operation becomes
easy, The above problems can be eliminated.
Also, the number of wires is reduced.
[0071]
Further, according to the present invention, even if it is intended to change the front / rear
balance and lower the volume on the rear side, the bass level is not changed but only the midhigh tone level is lowered, so that sufficient bass can be reproduced. Also, even if the overall
volume changes, the amount of bass can be adjusted accordingly, so that good sound quality can
be maintained.
[0072]
Further, according to the present invention, there is an effect that the application to a stereo of
an apparatus in which the bass reproduction system is monaural is easy.
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[0073]
Furthermore, according to the present invention, when the left and right volume balance is
adjusted, the output level of the bass does not change, so that sufficient volume can always be
reproduced.
[0074]
Brief description of the drawings
[0075]
1 is a circuit diagram of a vehicle-mounted acoustic device according to a first embodiment of the
present invention.
[0076]
2 is a circuit diagram of a vehicle-mounted acoustic device according to a second embodiment of
the present invention.
[0077]
3 is an explanatory view of the volume for series fader in FIG.
[0078]
4 is a characteristic diagram of the series fader volume of FIG.
[0079]
5 is a connection explanatory diagram of a speaker according to a third embodiment of the
present invention.
[0080]
<Figure 6> It is the flowchart which explains the procedure of execution example 4 of this
invention.
[0081]
<Figure 7> It is the flowchart which explains the procedure of execution example 5 of this
invention.
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[0082]
FIG. 8 is a circuit diagram of a vehicle-mounted acoustic device of a seventh embodiment of the
present invention.
[0083]
<Figure 9> It is the flowchart which shows the operation of the execution example 7 of this
invention.
[0084]
10 is a flowchart showing the operation of Embodiment 8 of the present invention.
[0085]
FIG. 11 is a characteristic view of attenuation amount change of the seventh embodiment of the
present invention.
[0086]
12 is an attenuation amount change characteristic diagram of the eighth embodiment of the
present invention.
[0087]
FIG. 13 is a circuit diagram of a vehicle-mounted acoustic device of a tenth embodiment of the
present invention.
[0088]
14 is a characteristic diagram for explaining the operation of the tenth embodiment of the
present invention.
[0089]
FIG. 15 is a circuit diagram of a vehicle-mounted acoustic device of a twelfth embodiment of the
present invention.
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[0090]
FIG. 16 is an operation characteristic diagram of Embodiment 11 of the present invention.
[0091]
FIG. 17 is a circuit diagram of a conventional in-vehicle acoustic device.
[0092]
18 is a diagram showing the structure of the para-fader variable resistor of FIG.
[0093]
19 is a characteristic diagram of the para-fader variable resistor of FIG.
[0094]
FIG. 20 is a circuit diagram of a conventional in-vehicle acoustic device.
[0095]
Explanation of sign
[0096]
REFERENCE SIGNS LIST 1 amplifier 2 front (for front) speaker 21 rear (for rear) speaker 6 single
pole double throw switch 31 center click parafader type variable resistor 8 center click series
fader type variable resistor 211 woofer 212 middle range speaker 213 tweeter 11 a Front signal
11b Rear signal 14a High pass filter 14b Front signal amplification means 16a High pass filter
16b Rear middle high tone signal amplification means 16c Rear middle high tone output 17a
Low pass filter 17b Rear bass signal amplification means 17c Rear bass output 18
Microcomputer 19 operation unit 21H Rear middle high and low pitch speaker 21L Rear bass
speaker 40 Front signal attenuation means 50H Rear middle and high tone signal attenuation
means 50L Rear bass signal attenuation means 41, 51H, 51L Attenuation amount detection
means 42, 52H, 5 Control device of L attenuation means 22 Diode 101 Amplifier 102 Front
speaker 113 Sound quality / sound field correction means 114a High pass filter 114b Front
signal amplification means 116a High pass filter 116b Rear middle high tone signal amplification
means 121H Rear middle high tone speaker 140 Front signal attenuation means 141, 151H
Damping amount detecting means 142, 152H Control device of damping means
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