DESCRIPTION JP2008191315

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DESCRIPTION JP2008191315
The present invention provides an acoustic device capable of accurately performing time
alignment correction in any audio output system having a plurality of speakers. A
synchronization measurement signal generation unit (115A) of a control unit (110A) generates a
test sound signal according to frequency characteristics of each speaker constituting an audio
device. Then, based on the sound collection result of the test sound signal by the sound collection
unit 140, the signal output unit 113 adjusts the sound output timing among the plurality of
speakers. As a result, time alignment correction can be accurately performed even in any audio
output system having a plurality of speakers.
Acoustic device, method thereof, program thereof and storage medium thereof
[0001]
The present invention relates to an acoustic device, a sound reproduction processing method
used in the acoustic device, a sound reproduction processing program for executing the sound
reproduction processing method, and a storage medium on which the sound reproduction
processing program is recorded.
[0002]
In recent years, with the spread of CDs (Compact Disks) and DVDs (Digital Versatile Disks), multisurround sound devices have been developed.
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As a result, it is possible to enjoy realistic surround sound not only in the home space but also in
the vehicle space.
[0003]
By the way, the installation environment of the audio device is various, and it often happens that
a speaker for outputting sound can not be arranged at a position having symmetry (hereinafter,
also simply referred to as “symmetry”) in the viewpoint of multi-surround system. In
particular, when a multi-surround type audio device is mounted on a vehicle, restrictions on the
seating position, which is the listening position, and the restrictions on the position where the
speakers can be arranged are severe, and each speaker and listening position (for example,
driving The positional relationship with the seat can not have symmetry in terms of the multisurround system. When the positional relationship between each speaker and the listening
position does not have symmetry in the viewpoint of the multi-surround system, localization and
presence of sound at the listening position are degraded.
[0004]
For this reason, when the positional relationship between each speaker and the listening position
in the acoustic device does not have symmetry, it is necessary to correct the propagation
characteristics of the sound from each speaker to the listening position. As this correction
method, there is time alignment correction in which the signal output from the speakers is
delayed in advance so that the sounds from the speakers can simultaneously arrive at the
listening position.
[0005]
As a method of setting a delay time in this time alignment correction, a test voice signal of a fixed
constant frequency is driven to a speaker, and the sound pressure of the acoustic radiation at the
listening position is maximized at the time when the test voice signal is maximum. There is a
method of calculating a time difference with a certain time and setting a delay time to an output
sound signal input to a speaker based on the time difference (refer to Patent Document 1 etc .:
hereinafter referred to as “conventional example”) .
[0006]
Japanese Patent Application Laid-Open No. 7-87598
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[0007]
The above-described conventional time alignment correction generates a test audio signal of a
fixed constant frequency even in any audio output system having a plurality of speakers.
For this reason, when the frequency of the test sound signal is not appropriate for a certain
speaker, it is difficult to obtain a good test sound signal level at the listening position and a noise
level ratio (SN ratio) due to noise or the like.
If a good SN ratio can not be obtained, the measurement error becomes large, and it is not
possible to ensure the accuracy of time alignment correction.
[0008]
For example, for a two-way speaker consisting of two speakers, a high-pitched part reproduction
speaker (hereinafter also referred to as "tweeter") and a low-pitched part reproduction speaker
(hereinafter also referred to as "woofer") It may not be possible to make corrections. That is,
since the above two speakers have largely different frequency characteristics, for example, if the
frequency of the test sound signal is set too low in accordance with the woofer, the acoustic
radiation pressure of the tweeter can hardly be obtained. I will. Conversely, if the frequency of
the test audio signal is set too high in accordance with the tweeter, the acoustic radiation
pressure of the woofer will be hardly obtained, and the test audio signal level and the noise level
are good. Ratio (SN ratio) can not be obtained. Furthermore, with regard to the tweeter, there is a
risk that the device may be damaged if a bass range signal that can not be reproduced is input.
[0009]
Therefore, there is a need for a technology that can accurately perform time alignment correction
in any audio output system having a plurality of speakers. Responding to such a request is one of
the problems to be solved by the present invention.
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[0010]
The present invention has been made in view of the above circumstances, and provides a new
acoustic device and a sound reproduction processing method capable of correcting the
propagation characteristics of sound appropriately when a music or the like is viewed. With the
goal.
[0011]
The invention according to claim 1 is an acoustic device for outputting sound from a plurality of
speakers toward a sound field space, wherein the sound collection means performs sound
collection at a predetermined sound collection position in the sound field space; Calculation
means for calculating an audio waveform for synchronization suitable for measuring the arrival
time of the output sound to the sound collection means based on the frequency characteristic
regarding the sound output for each of the plurality of speakers; from each of the plurality of
speakers Adjustment means for sequentially outputting synchronization test speech of the
corresponding synchronization speech waveform, and adjusting an audio output timing among
the plurality of speakers based on a collection result of the synchronization test speech by the
sound collection means And an acoustic device characterized by comprising.
[0012]
The invention according to claim 6 is a calculation step of calculating, for each of a plurality of
speakers, an audio waveform for synchronization suitable for measuring an arrival time of an
output voice to the sound collecting means based on frequency characteristics related to voice
output. And sequentially outputting a synchronization test sound of the corresponding
synchronization sound waveform from each of the plurality of speakers and, based on the
collection result of the synchronization test sound by the sound collection unit, between the
plurality of speakers. And an adjusting step of adjusting the audio output timing in the above.
[0013]
A seventh aspect of the present invention is a sound reproduction processing program that
causes a computing unit to execute the sound reproduction processing method according to the
sixth aspect.
[0014]
An eighth aspect of the present invention is a recording medium on which the sound
reproduction processing program according to the seventh aspect is recorded so as to be
readable by an arithmetic unit.
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[0015]
Hereinafter, embodiments of the present invention will be described with reference to the
attached drawings.
In the following description, the same or equivalent elements will be denoted by the same
reference symbols, without redundant description.
[0016]
First Embodiment First, a first embodiment of the present invention will be described with
reference to FIGS.
In the first embodiment, an acoustic device mounted on a vehicle CR (see FIG. 2) will be
described as an example.
<Configuration> FIG. 1 is a block diagram showing a schematic configuration of the acoustic
device 100A according to the first embodiment.
As shown in FIG. 1, a control unit 110A and a drive unit 120 are provided.
[0017]
The sound device 100A also includes a sound output unit 1301, a sound output unit 1302, a
sound output unit 1303, a sound output unit 1304, a sound output unit 1305, a sound output
unit 1306, a sound output unit 1307, a sound And an output unit 1308.
[0018]
Here, the sound output unit 1301 has a tweeter 1311 for the left speaker, and the sound output
unit 1302 has a woofer 1312 for the left speaker.
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Further, the sound output unit 1303 has a light speaker tweeter 1313, and the sound output unit
1304 has a light speaker woofer 1314.
[0019]
Further, the sound output unit 1305 has a tweeter 1315 of surround left speaker, and the sound
output unit 1306 has a woofer 1316 of surround left speaker.
Further, the sound output unit 1307 has a tweeter 1317 of a surround light speaker, and the
sound output unit 1308 has a woofer 1318 of a surround light speaker.
[0020]
Further, the acoustic device 100A includes a sound collection unit 140 as a sound collection unit,
a display unit 150, and an operation input unit 160 as an operation input unit.
[0021]
The elements 120 to 160 other than the control unit 110A are connected to the control unit
110A.
[0022]
The control unit 110 </ b> A centrally controls the entire acoustic device 100 </ b> A.
The details of the control unit 110A will be described later.
[0023]
When the compact disk CD in which the sound content is recorded is inserted, the drive unit 120
reads the sound content for which the reproduction command has been issued from the compact
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disk CD when receiving the reproduction command of the sound content from the control unit
110A.
The readout result of the sound content is sent to the control unit 110A as content data CTD
which is an audio signal.
[0024]
Each of the sound output units 1301 to 1308 includes, in addition to the above-described
speakers, (i) a DA converter (Digital to Analog Converter) that converts digital audio data received
from the control unit 110A into an analog signal; And an amplifier for amplifying an analog
signal output from the DA converter. The sound output units 1301 to 1308 reproduce and
output a test sound signal, music and the like under the control of the control unit 110A.
[0025]
In this embodiment, as shown in FIG. 2, the tweeter 1311 of the left speaker of the sound output
unit 1301 and the woofer 1312 of the left speaker of the sound output unit 1302 are disposed in
the front door housing on the passenger seat side. The left speakers 1311 and 1312 are disposed
to face the front passenger seat.
[0026]
The tweeter 1313 of the light speaker of the sound output unit 1303 and the woofer 1314 of the
light speaker of the sound output unit 1304 are disposed in the front door housing on the
driver's seat side. The light speakers 1313 and 1314 are disposed to face the driver's seat.
[0027]
The tweeter 1315 of the surround left speaker of the sound output unit 1305 and the woofer
1316 of the surround left speaker of the sound output unit 1306 are disposed in a casing at the
rear of the front passenger seat. These surround left speakers 1315 and 1316 are disposed to
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face the rear seat on the passenger seat side.
[0028]
The tweeter 1317 of the surround light speaker of the sound output unit 1307 and the woofer
1318 of the surround light speaker of the sound output unit 1308 are disposed in the rear
casing of the driver's seat. The surround light speakers 1317 and 1318 are disposed to face the
rear seat on the driver's seat side.
[0029]
Returning to FIG. 1, the sound collection unit 140 is (i) a microphone for collecting ambient
sound into an electrical analog audio signal, (ii) an amplifier for amplifying an analog audio
signal output from the microphone, (iii) And an AD converter (Analog to Digital Converter) for
converting an amplified analog audio signal into a digital audio signal. Here, the microphone is
disposed at a predetermined at least one position in the sound field space ASP. Sound collection
result data AAD by the sound collection unit 140 is reported to the control unit 110A.
[0030]
The display unit 150 is based on (i) a display device 151 such as a liquid crystal display panel, an
organic EL (Electro Luminescence) panel, or a PDP (Plasma Display Panel), and (ii) display control
data IMD sent from the control unit 110A. A display controller such as a graphic renderer that
controls the entire display unit 150, and (iii) a display image memory for storing display image
data, and the like. The display unit 150 displays operation guidance information and the like
under the control of the control unit 110A.
[0031]
The operation input unit 160 is configured of a key unit provided on the main body of the
acoustic device 100A, or a remote input device or the like including the key unit. Here, as a key
part provided in the main body part, a touch panel provided in the display device 151 of the
display unit 150 can be used. In addition, it can replace with the structure which has a key part,
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and can also employ | adopt the structure which voice-inputs.
[0032]
When the user operates the operation input unit 160, the setting of the operation content of the
acoustic device 100A is performed. For example, the user uses the operation input unit 160 to
set the frequency characteristics of the speakers, reproduce the sound content, and the like. Such
input contents are sent from the operation input unit 160 to the control unit 110A as operation
input data IPD.
[0033]
The control unit 110A controls the operation of the two sound output modes of the
"reproduction mode" and the "delay time setting mode" in the acoustic device 100A. Here, the
"reproduction mode" is a mode in which sound content is read out from the compact disc CD and
the audio signal is reproduced, and the "delay time setting mode" is generated by measuring a
test audio signal and measured. In this mode, delay time corresponding to each of the speakers
130 j is set in order to perform time alignment correction of the audio output timing from each
of 1 to 8).
[0034]
As shown in FIG. 3, the control unit 110A includes a control processing unit 111A as a
calculation unit and a delay control unit. The control unit 110A further includes a channel signal
processing unit 112, a signal delay unit 113 as a delay unit, an output signal selection unit 114,
and a synchronous measurement signal generation unit 115A as an adjustment unit.
[0035]
Control processing unit 111A analyzes operation input data IPD received from operation input
unit 160, and determines which sound output mode of "delay time setting mode" of
"reproduction mode" is set as sound device 100A. . Then, based on the analysis result, the control
processing unit 111A instructs each of the channel signal processing unit 112, the signal delay
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unit 113, the output signal selection unit 114, and the synchronization measurement signal
generation unit 115A that constitute the control unit 110A. Send
[0036]
Here, as a command sent from the control processing unit 111A, a content reproduction control
command CPC directed to the channel signal processing unit 112, a delay control command DLC
to the signal delay unit 113, and an output signal data to the output signal selecting unit 114
There are a selection command ODS and a synchronous measurement signal generation control
command SGC to the synchronous measurement signal generation unit 115A. These commands
will be described later.
[0037]
Further, in the “delay time setting mode”, the control processing unit 111A receives a report
of sound collection result data AAD by the sound collection unit 140 which collects the test voice
signal. Then, the control processing unit 111A analyzes the sound collection result data AAD, and
calculates delay times DL1 to DL8 (see FIG. 4) of the output sound signal input to each of the
speakers 1311 to 1318. Then, the calculation result is sent to the signal delay unit 113 together
with the delay control command DLC.
[0038]
Further, the control processing unit 111A displays, as display data IMD, information such as the
waveform of the test sound signal used for time alignment correction, the frequency
characteristic of each speaker, and the set delay time for the output sound signal input to each
speaker. Send to 150. As a result, the display device 151 of the display unit 150 displays these
pieces of information.
[0039]
The control processing unit 111A is provided with a timer circuit and a storage unit (both are not
shown) for performing time alignment correction.
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[0040]
When the operation input unit 160 reports that the content to be reproduced including sound
content is specified, the channel signal processing unit 112 should reproduce the content
according to the content reproduction control instruction CPC by the control processing unit
111A. The content data CTD corresponding to the content is read from the drive unit 120 and
developed to generate a digital sound data signal.
Subsequently, the channel signal processing unit 112 analyzes the generated digital sound data
signal, and supplies the digital sound data signal to each of the sound output units 1301 to 1308
described above according to the channel designation information included in the digital sound
data signal. Separate as it is. Thus, eight sound output separation data signals LOD1 to LOD8
which are data signals separated for each of the sound output units 1301 to 1308 are output to
the signal delay unit 113.
[0041]
The content reproduction control instruction CPC described above is issued from the control
processing unit 111A to the channel signal processing unit 112 when the acoustic device 100A
is in the “reproduction mode” described above.
[0042]
The signal delay unit 113 is provided with eight delay units 1131 to 1138 corresponding to the
eight sound output units 1301 to 1308 as shown in FIG. 4.
Each delay unit 113i (i = 1, 2,..., 8) delays the signal LODi which has been completely separated
by the channel signal processing unit 112 by the time DLi, in accordance with each signal delay
control command DLCi by the control processing unit 111A. The signal thus delayed by the delay
unit 113i is output to the output signal selection unit 114 as the output sound delay correction
data signal CODi.
[0043]
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As shown in FIG. 5, the output signal selection unit 114 includes eight switch elements 1141 to
1148 corresponding to the eight sound output units 1301 to 1308. Each of the switch elements
114i has terminals 114iA, 114iB, and 114iC. Here, the terminal 114iA is a terminal connected to
the signal delay unit 113, and the terminal 114iB is a terminal connected to the synchronous
measurement signal generation unit 115A. The terminal 114iC is a terminal connected to the
sound output unit 130i. The operation of each switch element 114i is performed according to
each output signal selection command ODSi by the control processing unit 111A.
[0044]
When the synchronization measurement signal generation unit 115A receives the
synchronization measurement signal generation control command SGC from the control
processing unit 111A in the “delay time setting mode”, the synchronization measurement
signal generation unit 115A generates a test audio signal SGD according to the frequency
characteristics of the speakers 1311 to 1318. generate. In the generation of the test speech
signal SGD, in the present embodiment, a method of discrete Fourier transform, that is, Z
conversion is used.
[0045]
Generally, as the frequency characteristics of the speaker 131 j (j = 1 to 8), the sound pressure X
j (f j, m) of the individual speaker 131 j at each of the frequencies f j, m (m = 1 to M) as shown in
FIG. Is obtained, the test sound waveform x j (t) (t: time) suitable for the speaker 131 j can be
calculated by performing Z <−1> conversion represented by the following equation (1). The test
speech waveform xj (t) thus calculated is as shown in FIG.
[0046]
C: Constant N: Number of samplings (odd number) TS: Sampling period
[0047]
Here, the constant C, the number of samplings N, and the sampling period TS are predetermined
in the synchronous measurement signal generation unit 115A.
[0048]
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In the present embodiment, prior to the operation in the “delay time setting mode”, the sound
pressure characteristic of the speaker obtained by referring to the speaker catalog etc. by the
user by the key operation of the operation input unit 160 is excellent. Only the information
corresponding to the minimum frequency value fmin, j and the maximum frequency value fmax, j
of the frequency range which is
That is, in the present embodiment, it is assumed that each of the speakers 131 j can be
approximated with the accuracy of the allowable range by the frequency characteristics as shown
in FIG.
[0049]
The minimum frequency value fmin, j and the maximum frequency value fmax, j input as
described above are registered in the control processing unit 111A.
The frequency characteristic information is sent from the control processing unit 111A to the
synchronous measurement signal generation unit 115A as a parameter of the synchronous
measurement signal generation control command SGC in the "delay time setting mode". The
synchronous measurement signal generation unit 115A having received the synchronous
measurement signal generation control command SGC sets the test sound signal xj as fmin, j = fj,
1 and fmax, j = fj, 2 according to the following equation (2) t) to calculate.
[0050]
[0051]
<Operation> The operation of the acoustic device 100A configured as described above will be
described mainly focusing on time alignment correction in the “delay time setting mode”.
[0052]
First, when the user selects the “delay time setting mode” by the input to the operation input
unit 160, the control unit 110A (more specifically, the control processing unit 111A) of the
acoustic device 100A performs step S11 in FIG. The speaker 1311 is selected as the first speaker
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for setting the delay time for time alignment correction.
[0053]
In step S11, when the control processing unit 111A selects one speaker, the control processing
unit 111A sends an output signal data selection instruction ODS to the output signal selecting
unit 114 (see FIG. 3).
Although the output signal data selection command ODS includes individual commands ODS1 to
ODS8 (see FIG. 5), when only the speaker 1311 is selected, the individual command ODS1
includes the synchronous measurement signal generator 115A and the sound output unit 1301.
And the terminal 1141B of the switch element 1141 and the terminal 1141C are brought into
conduction according to the command.
The other individual commands ODS2 to ODS8 are commands for not connecting the
synchronous measurement signal generation unit 115A and the sound output units 1302 to
1308, and settings according to the commands are performed in the switch elements 1142 to
1148.
[0054]
Subsequently, in step S12, the control processing unit 111A uses the frequency characteristic
information of the speaker 1311 registered therein as a parameter to execute a synchronous
measurement signal generation control command SGC to the effect that a test voice signal for the
speaker 1311 should be generated. It sends to the synchronous measurement signal generator
115A.
The synchronous measurement signal generation unit 115A having received the synchronous
measurement signal generation control command SGC performs the calculation of the abovementioned equation (2) according to the synchronous measurement signal generation control
command SGC, and generates a test voice signal SGD.
[0055]
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The test voice signal SGD generated by the synchronous measurement signal generation unit
115A is supplied to the sound output unit 1301 via the output signal selection unit 114 in which
the above-described switch setting is performed. As a result, in step S13, the test sound for the
speaker 1311 is output from the speaker 1311. Then, when the sound pressure of the test voice
becomes maximum, the time of the timer circuit built in the control processing unit 111A is set
to zero and started.
[0056]
Next, in step S14, the test voice output from the speaker 1311 is collected by the microphone of
the sound collection unit 140 installed at the listening position (for example, the driver's seat P1).
The sound collection result is sent to the control processing unit 111A as sound collection result
data AAD. Then, when the sound pressure of the test voice collected by the microphone becomes
maximum, the timer circuit of the control processing unit 111A started in step S13 is stopped.
[0057]
Next, in step S15, the timer value when the timer circuit of the control processing unit 111A is
stopped is stored in the storage unit as a propagation time to the sound collection position of the
output sound of the speaker 1311.
[0058]
The processes from step S12 to step S15 are performed for a predetermined number of times of
measurement.
Then, an average value of the measured propagation times is taken as an average propagation
time AD1 for the speaker 1311. The average propagation time AD1 is stored in the storage unit
of the control processing unit 111A.
[0059]
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In order to secure the measurement accuracy of the propagation time, only good sound
collection result data AAD is used to calculate the average propagation time. Here, good sound
collection result data AAD means that the maximum value a of the radiation pressure from the
speaker is sufficiently larger than the noise level b at the listening position, as shown in FIG.
Here, the noise includes white noise, noise coming from other spaces, and the like.
[0060]
Subsequently, in step S16, it is determined whether the average delay amount has been obtained
for all of the speakers 1311 to 1318.
[0061]
At this stage, the result of the determination in step S16 is negative (step S16: N), so the process
proceeds to step S17.
[0062]
In this step S17, the speaker 1312 is selected as a second speaker for performing time alignment
correction.
[0063]
After the speaker 1312 is selected, the processes from step S12 to step S15 described above are
performed.
[0064]
When the process from step S12 to step S15 is completed for all the speakers 1311 to 1318, the
result of the determination in step S16 is positive (step S16: Y), so the process proceeds to step
S18.
[0065]
In this step S18, using the average propagation times AD1 to AD8 of the speakers 1311 to 1318
stored in the storage unit of the control processing unit 111A, the control processing unit 111A
inputs the signals to the speakers 1311 to 1318 for time alignment correction. Delay time DL1 to
DL8 for delaying the output sound signal.
[0066]
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The calculation of the delay times DL1 to DL8 is performed as follows.
First, among the above average propagation times AD1 to AD8, the largest one is selected as the
maximum average propagation time ADmax.
Then, based on the maximum average propagation time ADmax, a time corresponding to the
difference between ADmax and the average propagation times AD1 to AD8 of the speakers is
calculated, and this is taken as delay times DL1 to DL8.
Therefore, the delay time DLi of the speaker 131i is given by calculating (ADmax−ADi).
[0067]
The delay times DL1 to DL8 calculated by the control processing unit 111A in this manner are
sent to the signal delay unit 113 together with the delay control command DLC.
[0068]
Subsequently, the operation of the “reproduction mode” for reproducing the sound content of
the compact disc CD after the delay time setting for time alignment correction is performed in
the “delay time setting mode” will be described.
[0069]
When the user designates "reproduction mode" by the input to operation input unit 160, control
processing unit 111A sends output signal data selection instruction ODS indicating "reproduction
mode" to output signal selecting unit 114. (See Figure 3).
Here, although the output signal data selection instruction ODS includes individual instructions
ODS1 to ODS8 (see FIG. 5), in the case of the "reproduction mode", the signal delay unit 113 and
all the sound output units 1301 to 1308 and The output signal selection unit 114 electrically
connects the terminal 114iA of the switch element 114i to the terminal 114iC in response to
each individual command ODSi issued to connect the
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[0070]
Further, when the setting of the “reproduction mode” is ended, the control processing unit
111A sends the content reproduction control instruction CPC to the channel signal processing
unit 112.
The channel signal processing unit 112 reads the content data CTD from the drive unit 120
according to the content reproduction control command CPC, and generates a digital sound data
signal.
Then, the channel signal processing unit 112 analyzes the digital sound data signal and separates
the digital sound data signal so as to be supplied to each of the sound output units 1301 to 1308
according to channel specification information or the like.
The sound output separation data signals LOD1 to LOD8 separated for each of the sound output
units 1301 to 1308 in this manner are output to the signal delay unit 113.
[0071]
The signal delay unit 113 delays the sound output separation data signal LODi by the delay times
DL1 to DL8 set in the delay units 1131 to 1138 in the “delay time setting mode” in
accordance with the signal delay control command DLC by the control processing unit 111A. .
The output sound delay correction data signals COD1 to COD8 thus delayed for each of the
sound output units 1301 to 1308 are output to the output signal selection unit 114.
[0072]
As described above, when the “reproduction mode” is set, the signal delay unit 113 and all the
sound output units 1301 to 1308 are connected in the output signal selection unit 114.
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Therefore, the output sound delay correction data signals COD1 to COD8 input to the output
signal selection unit 114 are output as the sound output data signals AOD1 to AOD8 toward the
corresponding sound output units 1301 to 1308. As a result, sounds based on the sound output
data signals AOD1 to AOD8 are output from the speakers 1311 to 1318 of the sound output
units 1301 to 1308.
[0073]
As described above, the acoustic device 100A of the first embodiment generates and outputs a
test voice signal according to the frequency characteristics of the speakers 1311-1318, and the
test voice signal reaches a predetermined sound collection position. Measure time And based on
this measurement result, time alignment correction is performed. Therefore, since the arrival
time of the test voice signal to the predetermined sound collection position can be measured with
high accuracy, it is possible to improve the localization and presence of the sound at the listening
position at the time of watching music etc. Can.
[0074]
Second Embodiment Next, a second embodiment of the present invention will be described
mainly with reference to FIGS. 11 to 14 and with reference to other drawings as appropriate.
Also in the second embodiment, as in the above-described first embodiment, an acoustic device
mounted on a vehicle CR (see FIG. 2) will be illustrated and described.
[0075]
<Configuration> FIG. 11 is a block diagram showing a schematic configuration of an acoustic
device 100B according to the second embodiment. As shown in FIG. 11, the acoustic device 100B
is different from the acoustic device 100A according to the first embodiment only in that a
control unit 110B is provided instead of the control unit 110A. Further, as shown in FIG. 12, the
control unit 110B includes a control processing unit 111B instead of the control processing unit
111A as compared with the control unit 110A according to the first embodiment, and a
synchronous measurement signal generating unit It differs in that a measurement signal
generation unit 115B is provided instead of 115A.
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[0076]
Note that, in addition to the two sound output modes of the “reproduction mode” and the
“delay time setting mode” of the first embodiment, each of the speakers 1311 to 1318
connected to the acoustic device 100B in the acoustic device 100B of the second embodiment.
There is a “characteristic measurement mode” that measures the frequency characteristics of
[0077]
Control processing unit 111B analyzes operation input data IPD received from operation input
unit 160, and based on the analysis result, channel signal processing unit 112, signal delay unit
113, and output signal selection unit 114 that constitute control unit 110B. , And sends a
command to each of the measurement signal generation units 115B.
[0078]
Among these, the instruction to be sent to each of the channel signal processing unit 112, the
signal delay unit 113, and the output signal selection unit 114 is the same as that of the control
processing unit 111A of the first embodiment.
On the other hand, the control processing unit 111B sends a command to the measurement
signal generating unit 115B, unlike the control processing unit 111A, the synchronous
measurement signal generation control instruction SGC, the characteristic measurement signal
generation control instruction FCC, and the signal. There are three types of selection command
SGS.
[0079]
About the content of said synchronous measurement signal generation control instruction |
command SGC, it is the same as that of 1st Embodiment.
Details of the characteristic measurement signal generation control instruction FCC and the
signal selection instruction SGS will be described later.
[0080]
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The control processing unit 111B is the same as the control processing unit 111A according to
the first embodiment, except for the functions other than the above, such as the timer circuit and
the storage unit.
[0081]
As shown in FIG. 13, the measurement signal generation unit 115 B includes a synchronization
measurement signal generation unit 115 A, a characteristic measurement signal generation unit
116 as an estimation unit, and a signal selection unit 117.
[0082]
The characteristic measurement signal generation unit 116 is an element that generates the
characteristic measurement signal FCD according to the characteristic measurement signal
generation control instruction FCC by the control processing unit 111B in the “characteristic
measurement mode”.
Here, the characteristic measurement signal FCD is a signal for measuring the frequency
characteristic of each of the speakers 1311 to 1318 connected to the acoustic device 100B.
The signal for measuring the frequency characteristic of the speaker is a sweep signal which
changes from 20 Hz to 20 kHz, which is an audible range, using a sine wave.
[0083]
Signal selection unit 117 generates test sound signal SGD generated by synchronous
measurement signal generation unit 115A in accordance with signal selection instruction SGS by
control processing unit 111B, and characteristic measurement signal FCD generated by
characteristic measurement signal generation unit 116. Select one or the other. In the “delay
time setting mode”, the test voice signal SGD is selected, and in the “characteristic
measurement mode”, the characteristic measurement signal FCD is selected. Then, one of the
selected signals is output to the output signal selection unit 114.
[0084]
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<Operation> The operation of the acoustic device 100B configured as described above will be
described mainly focusing on the operation of measuring the frequency characteristic of the
speaker in the above-mentioned “characteristic measurement mode”.
[0085]
First, when the user designates “characteristic measurement mode” by the input to the
operation input unit 160, the control processing unit 111B directs the output signal selection
unit 114 to output signal data indicating that it is “characteristic measurement mode”. Send
selection command ODS (see FIG. 12).
As in the first embodiment described above, the output signal data selection instruction ODS
includes individual instructions ODS1 to ODS8 (see FIG. 5). When the “characteristic
measurement mode” is designated, the individual command ODS1 is a command for connecting
the measurement signal generation unit 115B and the sound output unit 1301, and according to
this command, the terminal 1141B and the terminal 1141C of the switch element 1141 Becomes
conductive. The other individual commands ODS2 to ODS8 are commands for not connecting the
measurement signal generating unit 115B and the sound output units 1302 to 1308, and
settings according to the commands are performed in the switch elements 1142 to 1148.
[0086]
Further, when the “characteristic measurement mode” is designated, the control processing
unit 111B sends the signal selection unit 117 a signal selection instruction SGS indicating that
the characteristic measurement signal FCD should be selected (see FIG. 13). As a result, in the
“characteristic measurement mode”, the characteristic measurement signal FCD generated by
the characteristic measurement signal generation unit 116 is sent from the measurement signal
generation unit 115B to the output signal selection unit 114 as the measurement signal MSD.
[0087]
Subsequently, the control processing unit 111B sends the characteristic measurement signal
generation control command FCC to the characteristic measurement signal generation unit 116
to request generation of the characteristic measurement signal FCD.
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[0088]
The characteristic measurement signal generation unit 116 that has received the characteristic
measurement signal generation control command FCC generates a characteristic measurement
signal FCD for measuring the frequency characteristic of the speaker 1311 that is a tweeter.
In the second embodiment, as the characteristic measurement signal FCD, a sine wave sweep
signal in which the frequencies f1 and m sequentially change within the audible range of 20 Hz
to 20 kHz is adopted. The range of the frequency of the characteristic measurement signal FCD
generated by the characteristic measurement signal generator 116 can be arbitrarily set by the
user.
[0089]
The characteristic measurement signal FCD generated by the characteristic measurement signal
generation unit 116 is supplied to the sound output unit 1301 after sequentially passing through
the signal selection unit 117 and the output signal selection unit 114. As a result, sound based on
the characteristic measurement signal FCD is output from the speaker 1311.
[0090]
The sound output from the speaker 1311 is collected by the microphone of the sound collection
unit 140 installed at the listening position. The sound pressure X1 (f1, m) at the frequency f1, m,
which is the sound collection result, is sent to the control processing unit 111B as the sound
collection result data AAD, and is stored in the storage unit.
[0091]
The control processing unit 111B repeats the above measurement a predetermined number of
times, and uses the frequency f1, m and the sound pressure X1 (f1, m) at the frequency f1, m as
frequency characteristic information together with the sampling number N and the sampling
cycle TS. Register in the storage unit. An example of the frequency characteristic of the speaker
1311 thus identified is shown by a solid line in FIGS. 14 (A) and 14 (B).
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[0092]
Next, under the control of the control processing unit 111 </ b> B, processing of measuring and
registering the frequency characteristic of the audio output regarding the speaker 1312 which is
the woofer is performed. First, the control processing unit 111B sends an output signal data
selection instruction ODS for connecting the measurement signal generating unit 115B and the
sound output unit 1302 to the output signal selecting unit 114. The individual command ODS2
in this case is a command for connecting the measurement signal generation unit 115B and the
sound output unit 1302, and according to this command, the terminal 1142B and the terminal
1142C of the switch element 1142 are brought into conduction. The other individual commands
ODS1 and ODS3 to ODS8 are commands for not connecting the measurement signal generating
unit 115B and the sound output units 1301 and 1303 to 1308, and the settings according to
these commands are the switch elements 1141 and 1143 to 1148. It takes place at
[0093]
Next, the control processing unit 111B sends a characteristic measurement signal generation
control instruction FCC to the characteristic measurement signal generation unit 116.
Characteristic measurement signal generation unit 116 having received characteristic
measurement signal generation control command FCC generates characteristic measurement
signal FCD for measuring the frequency characteristic of speaker 1312. The characteristic
measurement signal FCD generated by the characteristic measurement signal generation unit
116 is supplied to the sound output unit 1302 after sequentially passing through the signal
selection unit 117 and the output signal selection unit 114.
[0094]
The sound output from the speaker 1312 is collected by the microphone of the sound collection
unit 140. The sound pressure X2 (f2, m) at the frequency f2, m, which is the sound collection
result, is sent to the control processing unit 111B as the sound collection result data AAD, and
stored in the storage unit. The control processing unit 111B repeats the above measurement a
predetermined number of times, and uses the frequency f2, m and the sound pressure X2 (f2, m)
at the frequency f2, m as frequency characteristic information together with the sampling
number N and the sampling cycle TS. Register in the storage unit. An example of the frequency
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characteristic of the speaker 1312 thus identified is shown by a two-dot chain line in FIGS. 14 (A)
and 14 (C).
[0095]
Hereinafter, similarly to the measurement of the frequency characteristics of the speakers 1311
and 1312 described above, processing of measurement and registration of the frequency
characteristics of the audio output regarding the speakers 1303 to 1308 is performed under
control of the control processing unit 111B.
[0096]
When the measurement of the frequency characteristics of the speakers 1311 to 1312 in the
“characteristic measurement mode” is completed and the user subsequently designates the
“delay time setting mode”, the control processing unit 111B firstly directs the signal selection
unit 117. And sends a signal selection command SGS to select the test voice signal SGD.
Next, the control processing unit 111B sends the synchronization measurement signal generation
control command SGC to the synchronization measurement signal generation unit 115A.
[0097]
Based on the detailed frequency characteristic information of each of the speakers 1311 to 1312
obtained by the measurement in the “characteristic measurement mode”, the synchronous
measurement signal generation unit 115A performs the calculation of the equation (1) described
above, and a test voice signal Generate SGD The setting process of the delay time after the test
voice signal SGD is generated is the same as the process in the first embodiment.
[0098]
Further, when the time alignment correction in the “delay time setting mode” is completed and
the user designates the “reproduction mode”, the audio content recorded on the CD is
reproduced as in the case of the first embodiment.
[0099]
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As described above, the acoustic device 100B of the second embodiment measures the detailed
frequency characteristics of the speakers 1311-1318, and generates and outputs a test voice
signal based on the frequency characteristic information. The arrival time of the test audio signal
to a predetermined sound collection position is measured.
And based on this measurement result, time alignment correction is performed. For this reason,
even if it is not possible to know the sound pressure characteristics of the speaker due to the loss
of the speaker catalog etc., it is possible to accurately measure the arrival time of the test voice
signal to the predetermined sound collecting position. It is possible to improve the sense of
localization and presence of sound at the listening position when watching etc.
[0100]
[Modification of Embodiment] The present invention is not limited to the above embodiment, and
various modifications are possible.
[0101]
For example, in the first and second embodiments described above, the drive unit 120 is a CD
drive unit, but may be a fixed disk or a DVD drive unit.
Furthermore, broadcast wave receiving circuits such as radio broadcasting and digital terrestrial
television broadcasting can also be used.
[0102]
Moreover, in said 1st and 2nd embodiment, although it was set as the 2 way speaker system, a 3
way speaker system may be sufficient and a 1 way speaker system may be sufficient.
[0103]
In the first and second embodiments described above, eight sound output units are provided, but
audio signals that are the result of reading the sound content are appropriately separated or
mixed, and seven or less or nine or more speakers are provided. It is also possible to output
sound from.
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[0104]
Further, in the first embodiment described above, only the values corresponding to the minimum
value fmin, j and the maximum value fmax, j shown in FIG. 8 are used as the frequency
characteristic information of each speaker, but more detailed frequency characteristic
information It can also be adopted.
For example, sound pressure Xj (fmin, j) and Xj (fmax, j) are input as frequency characteristic
information of the speaker 131j together with the minimum value fmin, j and the maximum value
fmax, j, and the test voice waveform is It may be calculated.
[0105]
Also, for the speaker 131j, the sound pressure Xj (fj, m) at each of the three or more frequencies
fj, m and the frequencies fj, m is input as frequency characteristic information, and the test voice
waveform is calculated by equation You may do it.
[0106]
Furthermore, based on the input frequency characteristic information, after a frequency
characteristic curve is determined for the speaker 131 j by a predetermined algorithm, a test
voice waveform is calculated by equation (1) using the frequency characteristic curve. You may
do it.
[0107]
In the second embodiment described above, a sweep signal of sine wave is used as the
characteristic measurement signal FCD. However, the speaker frequency characteristic is
determined by the characteristic measurement signal such as pink noise or TSP signal (time
stretch signal) and its acoustic response. Any information can be calculated.
[0108]
Further, in the second embodiment described above, the test sound waveform is calculated by the
equation (1) based on the detailed frequency characteristic information of the speaker 131 j.
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On the other hand, as shown in FIG. 15, the minimum frequency value fmin, j and the maximum
frequency value fmax, j in the frequency range in which the sound pressure characteristics of the
speaker 131 j are good are determined from an appropriate algorithm or the like. The test
speech waveform may be calculated by
[0109]
In the first and second embodiments described above, the present invention is applied to an
acoustic device mounted on a vehicle, but the present invention is also applied to an acoustic
device mounted on a mobile other than a vehicle. The present invention can also be applied to an
acoustic device that can not be mounted on a mobile body.
[0110]
A central processing unit (CPU: Central Processing Unit), a DSP (Digital Signal Processor), and a
read only memory (ROM: Read Only Memory) are used in part or all of the control units 110A
and 110B in the first and second embodiments described above. And a random access memory
(RAM: Random Access Memory), etc., and is configured as a computer as an arithmetic means,
and a computer program is prepared in advance and executed by the computer to partially or
entirely process the above embodiment. May be performed.
This program is recorded on a computer-readable recording medium such as a hard disk, a CDROM, a DVD, etc., and is read from the recording medium and executed by the computer.
Also, this program may be acquired in the form of being recorded on a portable recording
medium such as a CD-ROM, a DVD or the like, or may be acquired in the form of delivery via a
network such as the Internet. It is also good.
[0111]
It is a block diagram showing roughly composition of an audio system concerning a 1st
embodiment of the present invention.
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It is a figure for demonstrating the arrangement position of eight speakers of FIG.
It is a block diagram for demonstrating the structure of the control unit of FIG. It is a block
diagram for demonstrating the structure of the signal delay part of FIG. FIG. 5 is a block diagram
for explaining a configuration of an output signal selection unit of FIG. 3; It is a figure of the
frequency characteristic for demonstrating the method of Z conversion. FIG. 7 is a test speech
waveform obtained by applying Z <−1> conversion to the frequency characteristics shown in
FIG. 6; It is the figure which modeled the frequency characteristic of the speaker. It is a flowchart
for demonstrating time alignment correction. It is a figure for demonstrating the relationship
between the sound radiated from the speaker in a listening position, and noise. It is a block
diagram which shows roughly the structure of the audio equipment concerning 2nd Embodiment
of this invention. It is a block diagram for demonstrating the structure of the control unit of FIG.
It is a block diagram for demonstrating the structure of the synchronous measurement signal
generation part of FIG. It is a figure for demonstrating the frequency characteristic of a speaker.
It is a figure for demonstrating a modification.
Explanation of sign
[0112]
100A, 100B ... sound device 110A, 110B ... control unit 111A, 111B ... control processing unit
(calculation means, delay control means) 115A ... synchronous measurement signal generation
unit 116 ... characteristic measurement signal generation unit (estimation means) 120 ... drive
unit 1301 1308 ... Sound output unit 1311-1318 ... Speaker 140 ... Sound collection unit (sound
collection means) 160 ... Operation input unit (operation input means)
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