close

Вход

Забыли?

вход по аккаунту

?

JP2012227589

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2012227589
The present invention provides a digital speaker system capable of achieving both improvement
in reproduction capability and simplification of the configuration by using a plurality of speaker
units in one audio channel. A first signal processing unit (32A) generates a plurality of driving
digital signals (SS1 to SS6) from one digital audio signal (SB1) branched from an input digital
audio signal (SA); A second signal processing unit 32B that generates a single drive digital signal
SS7 from the audio signal SB2 and a plurality of drive digital signals SS1 to SS6 are supplied to a
speaker unit corresponding to one audio channel. A main speaker unit 22A having a voice coil
bobbin 23A having a plurality of voice coils, and a sub speaker unit 22B having a voice coil
bobbin 23B having a single voice coil to which a single drive digital signal SS7 is supplied It was
made to do. [Selected figure] Figure 1
デジタルスピーカーシステム
[0001]
The present invention relates to a digital speaker system that drives a speaker based on a digital
audio signal.
[0002]
There has been proposed a digital speaker system which converts digital audio signals into a
plurality of digital signals (drive digital signals) and directly inputs the plurality of voice coils to
reproduce voice (for example, see Patent Document 1).
09-05-2019
1
In this digital speaker system, the speaker unit is driven by obtaining the magnetic field
synthesized by adding the magnetic fields of the voice coils, so that low power consumption and
low voltage driving and high sound quality can be achieved.
[0003]
JP, 2009-71872, A
[0004]
However, in the conventional configuration, in the case where the speaker unit used for one
audio channel is configured by, for example, a two-way woofer for reproducing middle / low
range and a tweeter for high range, two similar structures are used. It must be prepared.
In this case, since each speaker is equipped with a plurality of voice coils, the vibration system
becomes heavy, and in particular, for a tweeter where the voice coil diameter is small and the
lightness of the vibration system is required, the high frequency reproduction ability is extremely
reduced and the manufacture is very serious. Problems will arise. Another problem is that the
number of parts is increased and the structure is complicated.
[0005]
The present invention has been made in view of the above-described circumstances, and a digital
speaker system capable of achieving both improvement in reproduction capability and
simplification of the configuration by using a plurality of speaker units for one audio channel. To
provide.
[0006]
In order to achieve the above object, the present invention performs, in a digital speaker system,
ΔΔ modulation processing and processing of converting a digital audio signal into a plurality of
driving digital signals to thereby process a plurality of driving digital signals. The first signal
processing unit to generate, a second signal processing unit to perform a ΔΣ modulation
process on the digital audio signal to generate a single drive digital signal, and the first signal
processing unit generates the first signal processing unit A first speaker unit having a voice coil
09-05-2019
2
bobbin provided with a plurality of voice coils to which a plurality of drive digital signals are
supplied, and a single to which the single drive digital signal generated by the second signal
processing unit is supplied And a second speaker unit having a voice coil bobbin having a voice
coil.
According to this configuration, since the first speaker unit includes the voice coil bobbin
including the plurality of voice coils to which the plurality of driving digital signals generated by
the first signal processing unit are supplied, a high speaker driving force can be obtained. be able
to. In addition, since the second speaker unit has a voice coil bobbin having a single voice coil to
which the single drive digital signal generated by the second signal processing unit is supplied,
the vibration system is light and parts are reduced. The score can be reduced. As a result, in the
configuration in which a plurality of speaker units are used for one audio channel, it is possible
to achieve both improvement in reproduction capability and simplification of configuration.
[0007]
In the above configuration, the second speaker unit may be a speaker unit that reproduces a
higher range than the first speaker unit. According to this configuration, the vibration system of
the second speaker unit in which the voice coil diameter is small and the lightness of the
vibration system is required can be lightened and the number of parts can be reduced, and the
high frequency reproduction capability can be improved Can be compatible with In the above
configuration, the first signal processing unit may include a shaping circuit that performs
shaping processing on the plurality of driving digital signals. According to this configuration, it is
possible to suppress the influence on the reproduced sound due to the variation of the plurality
of voice coils of the first speaker unit.
[0008]
Further, in the above configuration, a delay circuit may be provided to offset the difference in
processing time between the first signal processing unit and the second signal processing unit.
According to this configuration, both speaker units can be synchronized. In the above
configuration, a first filter for limiting a signal component corresponding to the reproduction
frequency range of the first speaker unit to a pass band in a stage before the first signal
processor, and a stage before the second signal processor. The signal processing apparatus may
further include a second filter for limiting a signal component corresponding to the reproduction
frequency range of the second speaker unit to a pass band. According to this configuration, the
09-05-2019
3
calculation amount in the first signal processing unit and the second signal processing unit can
be reduced, and the processing load on each signal processing unit can be reduced.
[0009]
Further, in the above configuration, a capacitor for noise removal may be disposed between the
second signal processing unit and the second speaker unit. According to this configuration, it is
not necessary to provide many capacitors for noise removal, and the configuration can be made
advantageous to high sound quality while suppressing the cost.
[0010]
According to the present invention, with the configuration in which a plurality of speaker units
are used for one audio channel, it is possible to achieve both improvement in reproduction
capability and simplification of the configuration.
[0011]
It is a figure which shows the electric constitution of the digital speaker system which concerns
on 1st Embodiment.
It is a block diagram of a 1st signal processing part. It is a figure which shows the electric
constitution of the digital speaker system which concerns on 2nd Embodiment. It is a figure
which shows the electric constitution of the digital speaker system which concerns on 3rd
Embodiment.
[0012]
Hereinafter, an embodiment of the present invention will be described with reference to the
drawings. First Embodiment FIG. 1 is a diagram showing an electrical configuration of a digital
speaker system according to a first embodiment. The digital speaker system 10 is applied to, for
example, an on-vehicle speaker system mounted on a vehicle, and a digital audio signal output
from an on-vehicle audio device (voice output device such as a CD player or car navigation
device) 11 mounted on the vehicle. And output the corresponding sound into the vehicle cabin.
09-05-2019
4
In general, a vehicle is equipped with a speaker system having 2 channels on the left or right or
5.1 channels (6 channels) or more. For example, the digital speaker system 10 of FIG. 1 is applied
to each audio channel on the front. And the other audio channel is applied with a single speaker
unit digital speaker system. The digital speaker system 10 performs various types of signal
processing on the digital audio signal SA output from the on-vehicle audio device 11 to generate
and output a driving digital signal, and the signal processing device 21 outputs the signal. The
main speaker unit 22A and the sub speaker unit 22B driven by the driving digital signal SS are
provided.
[0013]
The main speaker unit 22A is a woofer for medium-low range reproduction, and the sub speaker
unit (sub-speaker unit for high range reproduction) 22B is a tweeter for high range reproduction.
That is, in the present embodiment, the two-way system in which the two speaker units 22A and
22B cover the range is adopted, and the configuration is more advantageous to the sound quality
and the like than the one-way system in which the one range speaker covers the range. The main
speaker unit 22A is a multiple voice coil speaker (first speaker unit) having a voice coil bobbin
23A including multiple (six in the present embodiment) voice coils, and each voice coil is
supplied with a drive digital signal. As a result, the magnetic fields formed by the plurality of
voice coils can be added to obtain sufficient speaker driving force. As this multiple voice coil
speaker, widely known speakers disclosed in Japanese Patent Laid-Open No. 2009-71872 and
the like can be applied.
[0014]
The sub-speaker unit 22B is a speaker unit (second speaker unit) having a voice coil bobbin 23B
having a single voice coil, and is a general voice coil except that it is driven based on the digital
audio signal SA. It has the same structure as the speaker.
[0015]
The signal processing device 21 generates a drive digital signal SS from the signal input unit 31
to which the digital audio signal SA output from the in-vehicle audio device 11 is input and the
output signals (digital audio signals) SB1 and SB2 of the signal input unit 31. And a driver circuit
33 for driving the main speaker unit 22A and the sub speaker unit 22B based on the drive digital
signal SS.
09-05-2019
5
As shown in the figure, the input line connected to the signal input unit 31 is branched into two,
and the same digital audio signal SA is input to the signal input unit 31 in two systems, and the
signal input unit 31 and the signal processing unit 32 In the driver circuit 33, a signal line
(hereinafter referred to as a first signal line) L1 for a main speaker and a signal line (hereinafter
referred to as a second signal line) L2 for a sub speaker are provided independently. ing.
[0016]
The signal input unit 31 includes a low pass filter (LPF) 35 as a first filter and a first signal
adjustment circuit (EQ / Delay) 36 on the first signal line L 1, and on the second signal line L 2, A
high pass filter (HPF) 37 which is a second filter and a second signal adjustment circuit (EQ /
Delay) 38 are provided. The low pass filter 35 blocks high frequency signal components from the
digital audio signal SA, thereby passing middle and low frequency signal components
corresponding to the reproduction frequency range of the main speaker unit 22A. The first signal
adjustment circuit 36 is an equalizer / delay circuit for the main speaker, and performs change
(sound quality adjustment) and delay of audio frequency characteristics set in advance. The high
pass filter 37 blocks the mid- and low-frequency signal components from the digital audio signal
SA, thereby passing high-frequency signal components corresponding to the reproduction
frequency range of the sub speaker unit 22B. The second signal adjustment circuit 38 is an
equalizer / delay circuit for a sub-speaker, and performs change (sound quality adjustment) and
delay of audio frequency characteristics set in advance.
[0017]
In this embodiment, the equalizer function of the first signal adjustment circuit 36 performs
sound quality adjustment in accordance with the main speaker unit 22A, and the equalizer
function of the second signal adjustment circuit 38 performs sound quality adjustment in
accordance with the sub speaker unit 22B. By this, sound quality adjustment according to the
characteristic peculiar to each speaker unit 22A, 22B can be performed independently.
Furthermore, the delay function of the first and second signal conditioning circuits 36, 38 is used
to synchronize the audio output timing of both speaker units 22A, 22B. Specifically, in the
present embodiment, since the signal processing is performed independently for the first signal
line L1 and the second signal line L2, the signal processing time for each of the lines L1 and L2
can be different. In the section 32, the processing time of the first signal line L1 is longer than
that of the second signal line L2 because the processing time of the first signal line L1 is longer
by the amount of the mismatch shaping circuit 42 described later. The delay time of the second
09-05-2019
6
signal adjustment circuit 38 in the signal input unit 31 is set to be longer than that of the first
signal processing circuit 36 so as to eliminate the difference in the signal processing time. By
this, the signal processing time difference in the signal processing unit 32 can be offset to
synchronize the two speaker units 22A and 22B.
[0018]
Next, the signal processing unit 32 will be described. The signal processing unit 32 is configured
by an arithmetic processing circuit that performs various arithmetic processing, and roughly
classified, a first signal processing unit 32A provided on the first signal line L1 and a second
provided on the second signal line L2. And a two-signal processing unit 32B. The first signal
processing unit 32A is configured to include a Δ コ イ ル (delta sigma) modulation circuit 41 for
multiple coils and a mismatch shaping circuit 42, and the second signal processing unit 32B
includes the ΔΣ modulation circuit 43 for one coil. Is configured.
[0019]
FIG. 2 shows a block diagram of the first signal processing unit 32A. The Δ コ イ ル modulation
circuit 41 for multiple coils performs ΔΣ (delta sigma) modulation processing on the digital
audio signal (first digital audio signal) SB1 of the first signal line L1, and as shown in FIG. 45, a
multi-value ΔΣ modulation unit 46, and a code conversion unit 47. Then, the oversampling unit
45 oversamples the digital audio signal SB1 of the first signal line L1 to distribute the
distribution of requantization noise in a wide band, and ΔΔ modulation by the multi-value ΔΔ
modulation unit 46, Shape requantization noise. After that, the code conversion unit 47 converts
the multi-value bit output of the multi-value ΔΣ modulation unit 46 into an N-bit thermometer
code corresponding to the number of voice coils and outputs it. A plurality of (six in this
example) driving digital signals SS1 to SS6 (SS) corresponding to a plurality of voice coils and
capable of directly driving the main speaker unit 22A with digital signals by converting into a
thermometer code Generate Although the ΔΣ modulation circuit disclosed in Japanese Patent
Laid-Open No. 2009-71872 is applied to the Δ 複数 modulation circuit 41 for multiple coils, the
present invention is not limited to this, and other known ΔΔ modulations used for other DA
conversion etc. A circuit may be applied.
[0020]
09-05-2019
7
Here, when the plurality of drive digital signals SS output from the code conversion unit 47 are
supplied to the driver circuit 33 to drive the main speaker unit 22A, variations (variations in
impedance etc.) of the plurality of voice coils of the main speaker unit 22A ) Adversely affect the
playback sound. In this configuration, the mismatch shaping circuit 42 is provided on the output
side of the code conversion unit 47, and this mismatch shaping circuit 42 performs mismatch
shaping processing on a plurality of driving digital signals SS output from the code conversion
unit 47. This makes it possible to suppress the influence on the reproduced sound due to the
variations and noise of the plurality of voice coils. A wide variety of known mismatch shaping
circuits can be applied to this mismatch shaping circuit 42.
[0021]
A single coil ΔΔ modulation circuit 43 (see FIG. 1) performs ΔΔ (delta sigma) modulation
processing on the digital audio signal (second digital audio signal) SB2 of the second signal line
L2, and is a single voice coil Is different from the multi-coil ΔΣ modulation circuit 41 in that the
drive digital signal SS7 (SS) corresponding to is generated, and other than that is substantially the
same as the multi-coil ΔΣ modulation circuit 41. The driving digital signal SS7 output from the
one coil ΔΣ modulation circuit 43 is supplied to the driver circuit 33 and is used to drive the
sub speaker unit 22B. Since the sub speaker unit 22B includes only a single voice coil, there is no
variation in the plurality of voice coils as present in the main speaker unit 22A. For this reason,
the mismatch shaping circuit is not required for the one-coil ΔΣ modulation circuit 43. That is,
in the one-coil ΔΣ modulation circuit 43, the process of generating the plurality of drive digital
signals SS and the mismatch shaping process are omitted as compared with the multiple-coil ΔΣ
modulation circuit 41, and the process for the multiple coils is omitted. The configuration is
simpler than that of the Δ 簡 素 modulation circuit 41.
[0022]
By the way, comparing the main speaker unit 22A with the sub speaker unit 22B, the sub
speaker unit 22B reproducing the high frequency is required to have a higher operation speed
than the main speaker unit 22A reproducing the low and middle frequency, but The energy is
much smaller. In other words, in the main speaker unit 22A that reproduces the middle and low
frequencies, much higher driving energy is required compared to the sub speaker unit 22B in
order to secure a sufficient sound pressure. In this configuration, the main speaker unit 22A is a
voice coil speaker having a plurality of voice coils, and a plurality of driving digital signals SS1 to
SS6 are supplied to all the voice coils to drive the plurality of voice coils. The magnetic field
formed by the voice coil can be added to obtain a high speaker driving force. Therefore, sufficient
09-05-2019
8
driving energy can be secured for regeneration of the middle and low range.
[0023]
Furthermore, in the present configuration, the sub-speaker unit 22B is a voice coil speaker
having a single voice coil, and the voice coil is supplied with the driving digital signal SS7 to drive
the voice coil. The voice coil bobbin 23B including the voice coil can be configured with a light
weight and a small number of parts while satisfying the speaker driving force. As a result, the
vibration system of the sub speaker unit 22B used in the digital speaker system 10 can be
lightened, the high frequency reproduction capability can be improved, and the number of parts
can be reduced. Therefore, the configuration can be simplified while improving the regeneration
capability, the production can be facilitated, and the cost can be reduced.
[0024]
As described above, according to the present embodiment, the digital audio signal SA is branched
in the digital speaker system 10 that drives the speaker unit with the drive digital signal SS
generated by performing the ΔΣ modulation process on the digital audio signal SA. The first
signal processing unit 32A that generates a plurality of driving digital signals SS1 to SS6 from
one digital audio signal SB1 and the single driving digital signal SS7 from the other digital audio
signal SB2 that branches the digital audio signal SA And a voice coil bobbin 23A including a
plurality of voice coils to which a plurality of driving digital signals SS1 to SS6 are supplied, and a
speaker unit corresponding to one audio channel. Main speaker unit (1st speaker unit ) 22A and
a sub-speaker unit (second speaker unit) 22B having a voice coil bobbin 23B having a single
voice coil to which a single drive digital signal SS7 is supplied, so both speaker units 22A, The
vibration system of the sub-speaker unit 22B can be made light and the number of parts can be
reduced while securing a sufficient speaker driving force required for the 22B, and both the
improvement of the reproduction capability and the simplification of the configuration can be
achieved. it can. This makes it possible to realize a high-quality low-cost digital speaker system
10.
[0025]
Moreover, since the sub-speaker unit 22B is a tweeter that reproduces a treble range than the
main speaker unit 22A, the voice coil diameter can be small and the tweeter's requirement for
09-05-2019
9
lightness of the vibration system can be satisfied, so It is possible to achieve both the
improvement of the capability and the simplification of the configuration. In addition, since the
first signal processing unit 32A includes the mismatch shaping circuit 42 that performs
mismatch shaping processing on the plurality of driving digital signals SS1 to SS6, the
reproduced sound is generated due to the variation of the plurality of voice coils included in the
main speaker unit 22A. You can reduce the impact. On the other hand, since the second signal
processing unit 32B does not include the mismatch shaping circuit, the configuration of the
second signal processing unit 32B can be simplified.
[0026]
Furthermore, since the signal adjustment circuits 36 and 38 that function as delay circuits for
offsetting the difference in processing time between the first signal processing unit 32A and the
second signal processing unit 32B are provided, as described above, the first signal processing is
performed. Even if the signal shaping time is different from each other due to the mismatch
shaping circuit 42 in the section 32A and the mismatch shaping circuit in the second signal
processing section 32B, etc., the two speaker units 22A and 22B are synchronized. Can. In the
present configuration, the case where the two signal adjustment circuits 36 and 38 functioning
as delay circuits are provided has been described, but the point is that the signal on the side of
the second signal processing unit 32B, which has a shorter processing time, is delayed. Only the
second signal adjustment circuit 38 may be provided. Further, the positions of the signal
adjustment circuits 36 and 38 can be changed as appropriate.
[0027]
Further, in this configuration, a low pass filter (first filter) 35 for limiting a signal component
corresponding to the reproduction frequency range of the main speaker unit 22A to a pass band
at a stage before the first signal processing unit 32A, and a second signal processing unit 32B.
And a high pass filter (second filter) 37 for limiting the signal component corresponding to the
reproduction frequency range of the sub speaker unit 22B to the pass band, the first signal
processing unit 32A and the second signal processing unit 32B The amount of computation can
be reduced, and the processing load on each of the signal processing units 32A and 32B can be
reduced.
[0028]
Second Embodiment FIG. 3 shows a second embodiment.
09-05-2019
10
In the second embodiment, a capacitor C1 for removing noise is provided between the second
signal processing unit 32B and the sub speaker unit (second speaker unit) 22B. The capacitor C1
is provided between the signal line LS between the second signal processing unit 32B and the
sub-speaker unit 22B and a ground line (not shown), and removes high-frequency noise
components to achieve high-frequency reproduction capability. Improve. In the conventional
digital speaker system provided with a plurality of voice coils, since there are many signal lines
connecting the signal processing unit and each voice coil of the speaker unit, the capacitor C1 for
noise removal as described above is employed. If it tries, the capacitor C1 will be needed for the
number of signal lines, the number of parts will increase and the cost will become high. On the
other hand, in the present configuration, since the sub-speaker unit 22B is configured as a single
voice coil, it is not necessary to provide many capacitors C1 for noise removal, and the
configuration is advantageous for high frequency reproduction while suppressing costs. be able
to.
[0029]
Third Embodiment FIG. 4 shows a third embodiment. In the third embodiment, a mode applied to
a 3-way speaker system is shown, and a high-pass speaker unit (corresponding to a tweeter) 22B
for high-pass playback and a mid-range speaker unit for mid-pass playback (squaker)
(Equivalent) 22C and a low frequency speaker unit (corresponding to a woofer) 22A for low
frequency reproduction. The high-frequency speaker unit 22B and its peripheral configuration
are substantially the same as the sub-speaker unit 22B and its peripheral configuration of the
above embodiment, and the low-frequency speaker unit 22A and its peripheral circuits are the
main speakers of the above embodiment. Since the unit 22A and its peripheral circuits are
substantially the same, the same reference numerals are given and redundant description will be
omitted. The same reference numerals are given to the same configuration as the above
embodiment for the other configurations, and the redundant description will be omitted, and
different portions will be described in detail below.
[0030]
The mid-range speaker unit 22C is configured as a multiple voice coil speaker (first speaker unit)
having a voice coil bobbin 23C including a plurality of (three in this embodiment) voice coils. In
the signal processing device 21, the input line connected to the signal input unit 31 is branched
into three, and the same digital audio signal SA is input to the signal input unit 31 in three
09-05-2019
11
systems. The signal input unit 31, the signal processing unit 32, and the driver circuit 33 include
a first signal line L1 corresponding to the low band speaker unit 22A and a second signal line L2
corresponding to the high band speaker unit 22B. The third signal line L3 corresponding to the
midrange speaker unit 22C is provided independently.
[0031]
In the signal input unit 31, a band pass filter (BPF) 51 and a third signal adjustment circuit (EQ /
Delay) 52 are provided in the third signal line L3. The signal component corresponding to the
reproduction frequency range of 22 C is limited to the pass band, and the third signal adjustment
circuit 52 performs change (sound quality adjustment) and delay of the audio frequency
characteristics set in advance. In this case, the third signal adjustment circuit 52 adjusts the
sound quality in accordance with the mid-range speaker unit 22C, and sets the delay amount so
as to synchronize all the speaker units 22A to 22C. The low pass filter 35 of the second signal
line L2 passes only low frequency signal components corresponding to the reproduction
frequency range of the low frequency speaker unit 22A.
[0032]
In the signal processing unit 32, the third signal processing unit 32C is provided in the third
signal line L3, and the third signal processing unit 32C includes the Δ コ イ ル (delta sigma)
modulation circuit 53 for multiple coils and the mismatch shaping circuit 54. It is configured to
have. The Δ コ イ ル modulation circuit 53 for multiple coils performs ΔΣ modulation
processing on the digital audio signal (third digital audio signal) SB3 of the third signal line L3,
and in the Δ 変 調 modulation circuit 41 for multiple coils of the first signal line L1. Unlike the
case of generating six driving digital signals SS, the present embodiment is different from the
point of generating three driving digital signals SS, and is similar to the multiple coil ΔΔ
modulation circuit 41 except this point. In the mismatch shaping circuit 54, the mismatch
shaping circuit 42 of the first signal line L1 performs a mismatch shaping process on the six
driving digital signals SS, while a mismatch on the three driving digital signals SS is performed.
The difference is that the shaping process is performed, and it is the same as the mismatch
shaping circuit 42 except this point.
[0033]
09-05-2019
12
The driving digital signal SS output from the mismatch shaping circuit 54 is supplied to each
voice coil of the mid-range speaker unit 22C via the driver circuit 33, and the magnetic field
formed by each voice coil is added to be high. Speaker driving power can be obtained. As
described above, in the present configuration, the number of voice coils is reduced as the speaker
unit having the higher reproduction frequency range, so that the vibration system can be made
lighter as the speaker unit having the higher reproduction frequency range, and the speaker
having the higher reproduction frequency range The unit can meet the required high operating
speed. In addition, since a speaker unit having a low reproduction frequency range is driven by a
large number of voice coils, a speaker unit having a low reproduction frequency range can satisfy
the required driving energy.
[0034]
As described above, in the present configuration, the number of voice coils of the speaker units
22A to 22C is changed according to the frequency band and the driving energy, so the operating
speed and the driving energy desired for each of the speaker units 22A to 22C are satisfied. can
do. In general, the voice coil diameter is smaller as the speaker unit having a higher reproduction
frequency range, but in this configuration, the number of voice coils is smaller as the speaker
unit having a higher reproduction frequency range, thus simplifying the configuration and
facilitating manufacture .
[0035]
The embodiment described above is merely an aspect of the present invention, and any
modification is possible within the scope of the present invention. For example, although the
above embodiment describes the case of applying the present invention to a 2 way or 3 way
digital speaker system, the present invention is not limited to this, for example, can be applied to
a 4 way digital speaker system. It can be widely applied to digital speaker systems that use
multiple speaker units in a channel. Furthermore, the present invention can be applied to digital
speaker systems other than in-vehicle speaker systems. In the above embodiment, the mismatch
shaping circuit 42 is provided. However, the present invention is not limited to this, and another
shaping circuit such as a noise shaping circuit may be provided.
[0036]
DESCRIPTION OF SYMBOLS 10 digital speaker system 11 in-vehicle audio device 21 signal
processing device 22A main speaker unit (speaker unit for low frequency band, first speaker
09-05-2019
13
unit) 22B sub speaker unit (speaker unit for high frequency band, second speaker unit) 22C midrange speaker unit (First speaker unit) 23A to 23C voice coil bobbin 31 signal input unit 32
signal processing unit 33 driver circuit 35 low pass filter (first filter) 36 first signal adjustment
circuit (equalizer / delay circuit) 37 high pass filter (second filter) 38 Second signal adjustment
circuit (equalizer / delay circuit) 41, 53 ΔΣ modulation circuit for multiple coils 42, 54
Mismatch shaping circuit 43 ΔΣ modulation circuit for one coil C 1 capacitor S , SB1~SB3 digital
audio signal SS driving digital signal
09-05-2019
14
Документ
Категория
Без категории
Просмотров
0
Размер файла
26 Кб
Теги
jp2012227589
1/--страниц
Пожаловаться на содержимое документа