JPH0622388A - Acoustic characteristic adjusting device - Google Patents

Abstract

PURPOSE:To easily set the parameter of an acoustic reproducing device corresponding to the acoustic characteristic of an acoustic space such as a vehicle chamber. CONSTITUTION:The parameter such as a frequency characteristic of an acoustic reproducing device 2 is adjusted so that the acoustic reproducing device 2 can adapted to the acoustic characteristic of a vehicle chamber 11 being the acoustic space where the acoustic reproducing device 2 is used. At that time, an acoustic characteristic adjusting device 1 is constituted of a selecting means which selects an acoustic signal source such as a compact disk player 3 or a cassette deck 4, sound volume adjusting means which adjusts a right-and-left balance or a front-and-back balance, frequency control means such as a tone control, and phase control means which arranges a phase at the listening position of a sound outputted from each speaker. Thus, an inputting and outputting circuit between each means can be omitted, and the acoustic characteristic can be highly precisely adjusted. And also, each above mentioned means is integratedly constituted so as to be carried, so that an operability can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acoustic characteristic adjusting apparatus used for supporting determination of parameters such as balance and frequency characteristic of an acoustic reproducing apparatus which is preferably implemented on a vehicle.

[0002]

2. Description of the Related Art In recent years, the function and performance of an on-vehicle sound reproducing device have been remarkably improved, and therefore, the user's demand for sound quality is extremely high. For this reason, it is necessary to finely set parameters such as balance and frequency characteristics of the sound reproducing device mounted on the automobile in accordance with the type of automobile.

In a typical prior art, a preamplifier for performing balance and tone control, a graphic equalizer, etc. are used in combination, and the set values of the preamplifier, the graphic equalizer, etc. are set based on the measurement result of the reproduced sound and the actual listening result. Is adjusted so that the desired characteristics are obtained.

[0004]

In the above-mentioned prior art,
An individual adjusting device is used for each function such as volume control and frequency control. Therefore, when a plurality of adjusting devices are connected and used, the S of the input / output circuit of each adjusting device is used.
/ N and distortion are superimposed, and it is impossible to perform highly accurate adjustment. In addition, it is necessary to connect and use each individual adjusting device, which requires time and effort for measurement and is inferior in portability.

Furthermore, in order to detect whether or not the sound of a predetermined sound pressure level necessary for measurement is output from the speaker mounted on the vehicle body, a measuring device is provided at the output terminal of the amplifier or the input terminal of the speaker. Need to be connected, and the measurement work is complicated. Such a problem is remarkable in the case of a device that reproduces sound in a vehicle room, which is a very special acoustic space as compared with a home or a small theater.

An object of the present invention is to provide an acoustic characteristic adjusting device capable of easily determining the parameters of the acoustic reproducing device.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a sound reproducing apparatus for adjusting parameters of the sound reproducing apparatus so as to match desired acoustic characteristics in the acoustic space in which the sound reproducing apparatus is used. A device, which selects one of a plurality of audio signal sources and outputs an audio signal from the selected audio signal source, and a volume control for adjusting the level of the audio signal from the selection device. Means, a frequency control means for adjusting the frequency characteristic of the sound signal from the volume adjusting means, and a phase control means for adjusting the phase of the sound signal from the frequency control means and outputting it to the sounding means. It is a device for adjusting acoustic characteristics.

Further, the volume adjusting means, the frequency controlling means and the phase controlling means of the present invention are provided at least for each of the front left, front right, rear left and rear right channels, and the volume adjusting means is left and right. Adjusting the balance and the front-rear balance, the phase control means sets the phase of the acoustic signal of the rear channel to that of the front channel according to the distance difference from the acousticizing means provided for each channel to the listening position. It is characterized in that it changes with respect to the phase of the acoustic signal.

Further, in the present invention, in relation to the selecting means, when the voltage level of the acoustic signal from the acoustic signal source is equal to or higher than a predetermined first voltage, the first display is performed, and the first display is performed. Is provided with an input monitoring means for performing a second display when the voltage is higher than the second voltage.

[0010]

According to the present invention, in measuring the acoustic characteristics of the acoustic space in which the acoustic reproducing apparatus is used, for example, the interior of an automobile, and determining the parameters of the acoustic reproducing apparatus in accordance with the acoustic characteristics. An acoustic characteristic adjusting device that includes a selecting unit, a volume adjusting unit, a frequency controlling unit, and a phase controlling unit and is integrally configured so as to be portable is used.

The selecting means selects one of the plurality of acoustic signal sources and outputs the acoustic signal from the selected acoustic signal source to the volume adjusting means of the next stage. The acoustic signal source is, for example, a pink noise generation source that serves as a reference signal for measuring with a measuring instrument, or a compact disk reproducing device or a magnetic tape reproducing device for performing an auditory inspection by actual acoustic listening. is there.

The volume adjusting means adjusts the level of the input acoustic signal, for example, the left / right balance or the front / rear balance. The sound signal from the volume adjusting means is input to the frequency controlling means, and the frequency characteristics are adjusted, for example, tone control, boost control, or cutting of high and low frequencies.

The acoustic signal from the frequency control means is input to the phase control means and corresponds to the difference in distance from the speaker provided to each of the front left, front right, rear left and rear right channels to the listening position. Then, the phase control between the channels is performed. That is, for example, by inverting the phase of the acoustic signal of the rear channel with respect to the acoustic signal of the front channel or shifting it by an arbitrary phase amount, the phases of the acoustic waves radiated from the speakers and reaching the listening position are aligned. Adjusted. The acoustic signal thus adjusted is sonicated by a sonication device such as a speaker.

Therefore, the level and frequency characteristic of the acoustic signal can be adjusted with high accuracy in correlation with desired values, and the acoustic signal of the input / output circuit is deteriorated between the respective means in the adjusting device. It is possible to delete the configuration to be performed, which facilitates highly accurate adjustment of acoustic characteristics. In addition, as described above, the portable configuration allows easier adjustment.

[0015]

1 is a block diagram showing the electrical construction of an acoustic characteristic adjusting apparatus 1 according to an embodiment of the present invention, FIG. 2 is a front view of the acoustic characteristic adjusting apparatus 1, and FIG. FIG. 4 is a block diagram for explaining the configuration when the acoustic characteristic adjusting device 1 is incorporated in the vehicle-mounted acoustic reproducing device 2 and the parameters of the acoustic reproducing device 2 are determined. Note that, in FIG. 1, for simplification of description, only one channel of the left and right channels, for example, the left channel is shown, and the remaining right channel is configured in the same manner as the configuration of the left channel. The left and right channels are interlocked to adjust and adjust the phase characteristics.

The acoustic characteristic adjusting device 1 receives an acoustic signal from an acoustic signal source such as a compact disc player 3 or a magnetic tape reproducing device 4, and pink noise through an external input terminal 5. . Therefore, the rear plate 19 of the acoustic characteristic adjusting device 1 corresponds to the left and right channel input terminals PI1 corresponding to the compact disc player 3, the input terminal PI2 corresponding to the magnetic tape reproducing device 4, and the external input terminal 5. Input terminal PI
3 and 3 are provided.

The operator uses the pink noise to determine parameters corresponding to the acoustic characteristics of the passenger compartment 11 of the automobile, as will be described later, and the sound from the compact disc player 3 and the magnetic tape reproducing device 4 is used. Signal
The adjustment is made according to the actual hearing feeling of the listeners 12a and 13a in the vehicle compartment 11.

When the in-vehicle sound reproducing device 2 is actually used, a so-called primen amplifier or the like is used instead of the acoustic characteristic adjusting device 1. Therefore, the acoustic characteristic adjusting device 1 outputs the front left / right FL, FR, the rear left / right RL, RR, and the 5-channel acoustic signals of the low frequency range WO corresponding to the pre-amplifier. The acoustic signals of the respective channels are the power amplifiers AFL, AF.
R; ARL, ARR; AW (hereinafter, generically denoted by reference numeral A) is amplified, and then the corresponding speaker SF
L, SFR; SRL, SRR; SW (hereinafter referred to as a reference symbol S when collectively referred to) is sonicated.

In the vehicle compartment 11, the instrument panel 14 arranged in front of the seats 12, 13 at the listening position is provided with a front left channel speaker SFL on the left side from the listening positions 12, 13. The front right channel speaker SFR is disposed on the right side, and the low-frequency woofer SW is disposed in the center. Also in the passenger compartment 11
The seats 12,
Speaker S of the rear left channel on the left side facing the 13 side
RL is arranged, and the rear right channel speaker S is on the right side.
RR is arranged.

The compact disc player 3, the magnetic tape reproducing device 4 and the external input terminal 5 are rotary switches R which are selection means from the respective input terminals PI1 to PI3.
The acoustic signal input to each individual contact of S1 and from the common contact of the rotary switch RS1 is input to the main volume and loudness adjusting section 21. The adjusting unit 21 adjusts the level of the input acoustic signal in accordance with the set value of the variable resistor VR1, and the impedance elements Z1 to Z3 having different impedances connected to each other through the individual contacts of the rotary switch 2. Depending on which is selected, the correction amount of the loudness correction that emphasizes at least one of the low range and the high range is set, and after the acoustic signal is emphasized by the set correction amount, Output to the balance adjustment unit 22.

That is, as shown in FIG. 5, for example, when the voltage level of the input acoustic signal to the main volume and loudness adjusting section 21 is 0.5 Vrms and the 0 dB output level is 0.5 Vrms at 1 kHz, the main volume is set. If the rotary switch RS1 is connected to the contact not connected to the impedance element when the volume value of -40 dB is -40 dB, the output acoustic signal has a flat characteristic of -40 dB as indicated by reference sign α0. On the other hand, when the impedance element Z1 is selected,
When both the low range and the high range are greatly emphasized as indicated by reference numeral α1 and become impedance elements Z2 and Z3, the amount of emphasis and the sharpness change, and the reference numerals α2 and α
As indicated by 3, the characteristic becomes different from the characteristic indicated by the reference numeral α1.

These characteristics are those when the volume value of the main volume is -40 dB, and the characteristics continuously change according to the volume value of the main volume. For example, when the volume value of the main volume is 0 dB, the frequency characteristic is 0 dB regardless of which impedance element is selected by the rotary switch RS1.
Become flat.

The balance adjusting unit 22 is a variable resistor VR2.
The balance between the left and right of the input acoustic signal is adjusted according to the setting value of and is output to the tone control unit 23. The tone control unit 23 emphasizes the low range corresponding to the set value of the variable resistor VR3 and emphasizes the high range corresponding to the set value of the variable resistor VR4, and then, the front channel, the rear channel and the low range. Divide into channels and output.

When the input signal level to the tone control section 23 is 0.1 Vrms and the output voltage level at 1 kHz is 0.312 Vrms is 0 dB indicated by reference sign β0 in FIG. By adjusting the regulator VR3, from the flat characteristic of 0 dB indicated by the reference sign β0, the reference signs β1a and β1 can be obtained.
As shown by b, the low frequency side can be emphasized up to +12 dB and the high frequency side can be attenuated up to -12 dB.
Similarly, by adjusting the variable resistor VR4, from the flat characteristic of 0 dB indicated by the reference numeral β0, as shown by reference numerals β2a and β2b, the low frequency side is -12.
It can be attenuated to dB and the high frequency side can be emphasized to +12 dB. The so-called turnover frequency fT (frequency of ± 3 dB) in the tone control section 23 is, for example, 300 Hz on the low frequency side and 2 kHz on the high frequency side.

The front channel acoustic signal from the tone control unit 23 is input to the attenuator unit 24F, and the rear channel acoustic signal is input to the attenuator unit 24F.
The sound signal of the low frequency channel that is input to R is input to the attenuator unit 24W. Each attenuator section 24F, 24
Variable resistors VR5 and V are respectively provided to R and 24W.
R6 and VR7 are provided, and these variable resistors V
The gain can be adjusted in 1 dB steps by R5 to VR7. These attenuator parts 24
By adjusting the gain with F, 24R, 24W,
By compensating for the difference in output sound pressure level due to the difference in aperture and the difference in impedance of the speakers SFL, SFR; SRL, SRR; SW, desired left-right balance, front-back balance, and low-range balance can be obtained.

The acoustic signal of the front channel from the attenuator section 24F is input to the low-pass cut filter section 30F via the equalizer section 27F. The rear channel acoustic signal from the attenuator section 24R is input to the low-pass cut filter section 30R via the phase switching section 26R, the equalizer section 27R and the phase shifter section 29R. Furthermore, the acoustic signal of the low frequency channel from the attenuator unit 24W is supplied to the 3D switching unit 25 and the phase switching unit 26.
W, low-pass filter section 28, phase shifter section 29W
Is input to the low-frequency cut filter unit 30W via.

In the acoustic signal processing system of the front channel, the equalizer section 27F is a so-called CR type equalizer and has two rotary switches RS3 and RS4. The rotary switch RS3 has five contacts. By switching the rotary switch RS3, four resistors having resistance values R1 to R4 and a through line in which no resistor is interposed can be selected. Further, the rotary switch RS4 is provided with six individual contacts, and any one of the capacitors having electrostatic capacities C1 to C6 can be selected. FIG. 7 shows frequency characteristics when the electrostatic capacitance is switched to C1 to C6 for each resistance value R1 to R4. In FIG. 7, the input voltage level is 0.5 Vrms, and the state where the output voltage level is 0.5 Vrms at 1 kHz is 0 dB. By thus selecting the resistance values R1 to R4 and the electrostatic capacitances C1 to C6 in combination, the desired characteristic is selected from the boost curve shown in FIG. 7 and the frequency characteristic in the vehicle interior 11 is selected. The balance can be adjusted, that is, equalized.

In the rear channel acoustic signal processing system, the equalizer section 27R is constructed in the same manner as the equalizer section 27F, and the rotary switches RS5, RS6.
A desired boost curve can be obtained by switching between. Further, the phase switching unit 26R changes the phase of the input acoustic signal by 180 when the switch SW2 is turned on.
° Invert and output. Furthermore, the phase shifter part 29
The R has a rotary switch RS8. This rotary switch RS8 has eight individual contacts, and by switching these individual contacts, the through output of no signal processing and the phase of the bass range as shown in FIG. 8 are advanced by a desired angle. A signal processing output can be obtained.

That is, FIG. 8 (1) shows the gain characteristic of the phase shifter section 29R, and FIG. 8 (2) shows the phase characteristic. As is apparent from FIG. 8 (2), by selecting the rotary switch RS8, the frequencies at which the phase can be advanced by 90 ° are f1 to f7, for example, 5
0,80,125,200,315,500 and 70
It can be set to each frequency of 0 Hz. By the phase shifter unit 29R and the phase switching unit 26R, the sound of the front channel and the sound of the rear channel are added in the positive phase at the listening positions such as the driver seat 12 and the passenger seat 13 in the passenger compartment 11. , The bass range can be obtained efficiently.

Furthermore, in the acoustic signal processing system of the low frequency channel, the phase switching unit 26W is constructed in the same manner as the phase switching unit 26R, and by turning on the switch SW3, the phase of the input acoustic signal is inverted by 180 ° and output. can do. The phase shifter unit 29W has the same structure as the phase shifter unit 29R, and the phase of the bass range can be advanced by a desired angle by switching the rotary switch RS9.

The 3D switching unit 25 is provided with a switch SW8, and by making the switch SW8 conductive, the left and right channels of low-range sound with little directivity are reproduced by a common speaker, a so-called 3D system. In order to use the above, a monaural sound signal obtained by adding the input sound signals of both the left and right channels is created and output. When the switch SW8 is turned off, a normal stereo sound signal is output so that the bass sound can be reproduced by the left and right woofers in the same manner as the middle and high sound.

Furthermore, the low-pass filter section 28 includes
A changeover switch SW4 and a rotary switch RS7 are provided. The rotary switch RS7 has six individual contacts and has five cut-off frequencies f11 to f15, for example, 80, 90, 100, 120 and 150 Hz,
Through output can be selected. Also, by changing the changeover switch SW4, the attenuation characteristic is changed to -18d.
It is possible to select either B / oct or -12 dB / oct. Therefore, the attenuation rate is -12 dB / oc
FIG. 9 shows frequency characteristics when t is selected. In FIG. 9, the input signal level is 0.5 Vrms, and the output of 0.5 Vrms at 1 kHz is 0 dB.
In this way, it is possible to adjust the amount of bass and the texture in the passenger compartment 11.

Low-pass cut filter sections 30F, 30R and 30W are provided at the final stages of the signal processing systems of the front channel, the rear channel and the low-frequency channel configured as described above. The acoustic signal from the equalizer unit 27F is input to the low pass cut filter unit 30F. The low pass cut filter unit 30F is provided with a rotary switch RS10 and a changeover switch SW5. The rotary switch RS10 is provided with ten individual contacts, and like the rotary switch RS7 of the low pass filter unit 28, the through output and the cutoff frequencies of f21 to f29 can be selected. Changeover switch S
By switching W5, the attenuation characteristic is -6 dB /
It is possible to switch between oct and -12 dB / oct. Therefore, FIG. 10 shows the frequency characteristic of the low-pass cut filter unit 30F when the attenuation rate is set to −6 dB / oct. The cutoff frequencies f21 to f29 are 3
0,40,50,60,80,100,150,200
And 300 Hz. The input signal level is 0.
5 Vrms, 0.5 Vrms output at 1 kHz is 0
dB.

The low frequency cut filter section 30R is constructed in the same manner as the low frequency cut filter section 30F,
A changeover switch SW6 and a rotary switch RS11 are provided. Furthermore, the low-pass cut filter unit 30W is
It includes a changeover switch SW7 that changes the attenuation rate between -6 dB / oct and -12 dB / oct, and a rotary switch RS12 that is selectable between a through output and five cutoff frequencies f31 to f35. This low cut filter 30
FIG. 11 shows the frequency characteristic when the attenuation rate of W is set to −12 dB / oct. The cutoff frequencies f31 to f
35 is 20, 30, 40, 50 and 60H, respectively
z. In addition, the input voltage level is 0.5 Vrms,
The output of 0.5 Vrms at 1 kHz is 0 dB. As a result, it is possible to prevent the acoustic signal in the low sound range below the reproduction band from being input to each speaker S, and suppress the occurrence of undesired distortion.

On the front plate 18 of the acoustic characteristic adjusting apparatus 1, the variable resistors VR1 to VR7, the rotary switches RS1 to RS12, and the switches SW1 to SW7 as described above are provided in the front, rear, and low frequency channels. Correspondingly arranged.

Each of the low-pass cut filter sections 30F, 30
The acoustic signals from R and 30 W are output terminals PO1, PO2 and PO3 of the left and right channels provided on the back plate 19.
Is output from. The low-frequency channel acoustic signal from the output terminal PO3 is input to the speaker SW via the power amplifier AW as described above. The acoustic signals of the front channel from the output terminal PO1 are output from the parametric equalizers EQFL and EQFR for the left and right channels, respectively, through the power amplifiers AFL and AFR to the speakers SFL and SFR.
Input to FR. Furthermore, the acoustic signals of the rear channels from the output terminal P02 are parametric equalizers EQRL and EQR provided for each of the left and right channels.
It is input from R to the speakers SRL and SRR via the power amplifiers ARL and ARR.

Parametric equalizers EQFL, EQ
FR; EQRL and EQRR (hereinafter, referred to as a reference numeral EQ when collectively referred to) have, for example, four resonance frequencies that can be set arbitrarily, and the resonance sharpness at the resonance frequencies, that is, Q and boost / resonance. The dip gain can also be set arbitrarily.

As described above, at a predetermined listening position in the passenger compartment 11, the optimum acoustic parameters for the listening position are set by the variable resistors VR1 to VR7 and the switching states of the rotary switches RS1 to RS12. It can be easily obtained based on the above. Therefore, the acoustic parameters of the acoustic reproduction device 2 used in the vehicle interior 11 can be easily determined.

Further, by integrally forming the respective units 21 to 30 as described above, the configuration of the input / output circuit between the respective units can be omitted, and deterioration of the acoustic signal can be suppressed and highly accurate adjustment can be performed. be able to. Furthermore, the above-mentioned acoustic characteristic adjusting device 1 is configured to be portable, and this also allows the frequency characteristic to be adjusted more easily.

The power from the commercial frequency power source 62 from the power switch SW1 through the fuse 61 is rectified and smoothed by the constant voltage circuit 63 and then supplied to each circuit in the acoustic characteristic adjusting apparatus 1. There is.

On the other hand, the input acoustic signal selected by the rotary switch RS1 is also input to the input level monitor section 41. FIG. 12 is an electric circuit diagram of the input level monitor unit 41. The input level monitor unit 41 is roughly configured to include a mixing unit 42, a high-pass filter unit 43, a DC conversion unit 44, a window comparator unit 45, and display elements L1 and L2.

From the rotary switch RS1, a left channel acoustic signal is input via a line 40L, and a right channel acoustic signal is input via a line 40R. The acoustic signals of both channels are added by the mixing section 42 to be a monaural acoustic signal, and then input to the DC conversion section 44 via the high-pass filter section 43.

The mixing section 42 comprises a buffer 51 realized by a differential amplifier, resistors r1 to r3, and a capacitor c1. The high-pass filter unit 43 is configured to include a resistor r4 and a capacitor c2.

The DC converter 44 includes an integrated circuit 52 for rectifying an AC signal into a DC signal, and external capacitors c3 to c5 for smoothing the rectified signal. The DC converter 44 converts the effective value of the input AC signal into a DC voltage level and outputs it to the window comparator 45.

The window comparator 45 includes differential amplifiers 53 and 54, variable resistors vr1 and vr2, and a resistor r.
5 to r8 are included. DC converter 4
The output from 4 is divided by the voltage dividing resistors r5 and r6,
The signal is input to the non-inverting input terminal of the differential amplifier 53 and the inverting input terminal of the differential amplifier 54. The high-level voltage + B is applied to the inverting input terminal of the differential amplifier 53.
Is input by being divided by the resistor r7 and the variable resistor vr1, and the voltage + B is input to the non-inverting input terminal of the differential amplifier 54 by the resistor r8 and the variable resistor vr2.
It is divided by and input. That is, the movable piece of the variable resistor vr1 outputs the first reference voltage V1, and the movable piece of the variable resistor vr2 outputs the second reference voltage V2.

The reference voltages V1 and V2 are determined as follows. When a voltage applied to each speaker S to obtain a desired sound pressure level is V0, a gain of the acoustic characteristic adjusting device 1 and the parametric equalizer EQ is GV1, and a gain of each power amplifier A is GV2, the voltage is V1 is

[0047]

## EQU1 ## V1 = V0 / (GV1 × GV2) is selected. The acoustic characteristics of the vehicle interior 11 are typically measured when the output from each speaker S is 0.5 W.
Therefore, when the impedance of the speaker S is 4Ω, the voltage V0 is 1.41 Vrms. Therefore, the gain GV1 is 10 dB, and the gain GV1 is
When 2 is 20 dB, V1 = 44.6 mVrm
s.

When the upper limit of the voltage V0 applied to the speaker S is set to a value higher by 0.3 dB than the voltage V0,

[0049]

From 0.3 = 20 log (V2 / V1), V2 = 46.2 mVrms.

When the reference voltages V1 and V2 are set as described above, the output voltage from the DC converter 44 derived from the connection point 60 of the voltage dividing resistors R5 and R6 becomes the voltage V1.
When the above is reached, the differential amplifier 53 derives a high level output, and when it is less than V1, it derives a low level output. Further, the differential amplifier 54 derives a low level output when the output voltage from the DC converter 44 is less than the voltage V2, and derives a high level output when it is V2 or more.

The output terminal of the differential amplifier 53 is connected to a high-level power source + B via a pull-up resistor r9, and a display element realized by a light emitting diode or the like from the inverting buffer 55 via a current limiting resistor r10. It is connected to the cathode of L1. The anode of the light emitting diode L1 is connected to the power source + B. Therefore, when the potential of the connection point 60 becomes equal to or higher than the first reference voltage V1, the output of the differential amplifier 53 becomes a high level, the output is inverted by the inversion buffer 55, and the drive current flows through the display element L1.
1 lights up.

The output terminal of the differential amplifier 54 is connected to the power source + B via the pull-up resistor r11 and to the cathode of the display element L2 via the current limiting resistor r12. The anode of the display element L2 is connected to the high level power source + B, and therefore, when the potential of the connection point 60 becomes equal to or higher than the second reference voltage V2,
The output level of the differential amplifier 54 becomes a low level, a drive current flows through the display element L2, and the display element L2 lights up.

The display element L1 is, for example, a green light emitting diode, and the display element L2 is a red light emitting diode. Therefore, by adjusting the voltage level of the acoustic signal input to the input terminals PI1 to PI3 within a range in which the display element L1 is turned on and the display element L2 is turned off, the speaker 11 outputs from the passenger compartment 11 to the passenger compartment 11. It is possible to emit the sound having the optimum output sound pressure level necessary for measuring the acoustic characteristics. Thus, the optimum measurement conditions can be set by a simple operation of adjusting the input signal levels to the input terminals PI1 to PI3 while checking the two display elements L1 and L2. Therefore, the adjustment can be performed more easily than the adjustment method using a voltmeter or the like. Further, it is not necessary to directly measure the input signal level to each speaker S, and therefore the level adjustment can be easily performed.

[0054]

As described above, according to the present invention, since the selecting means, the volume adjusting means, the frequency controlling means and the phase controlling means are integrally configured, the parameters to be adjusted in each adjusting means are related to each other. Can be adjusted with high precision. Further, it is possible to reduce the number of input / output circuits and the like between the respective means, which makes it possible to suppress deterioration of the acoustic signal and perform more accurate adjustment. Furthermore, the above-mentioned respective means can be integrally carried so that the adjustment can be performed more easily.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of an acoustic characteristic adjusting apparatus 1 according to an embodiment of the present invention.

FIG. 2 is a front view of the acoustic characteristic adjusting device 1.

FIG. 3 is a rear view of the acoustic characteristic adjusting device 1.

FIG. 4 is a block diagram of a case where the acoustic characteristic adjusting apparatus 1 is incorporated into the vehicle-mounted acoustic reproducing apparatus 2 to determine a parameter corresponding to the acoustic characteristic of the vehicle interior 11.

FIG. 5 is a graph for explaining loudness characteristics of a main volume and a loudness adjusting unit 21.

FIG. 6 is a graph for explaining frequency characteristics of the tone control unit 23.

FIG. 7 is a graph for explaining frequency characteristics of equalizer units 27F and 27R.

FIG. 8 is a graph for explaining gain characteristics and phase characteristics of phase shifter units 29R and 29W.

FIG. 9 is a graph for explaining the frequency characteristic of the low-pass filter unit 28.

FIG. 10 is a graph for explaining frequency characteristics of low-pass cut filter units 30F and 30R.

FIG. 11 is a graph for explaining the frequency characteristic of the low-pass cut filter unit 30W.

FIG. 12 is an electric circuit diagram of an input level monitor unit 41.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Acoustic characteristic adjusting device 2 In-vehicle sound reproducing device 11 Vehicle compartment 21 Main volume and loudness adjusting unit 22 Balance adjusting unit 23 Tone control unit 24F, 24R, 24W Attenuator unit 25 3D switching unit 26R, 26W Phase switching unit 27F, 27R Equalizer Part 28 Low-pass filter part 29R, 29W Phase shifter part 30F, 30R, 30W Low-frequency cut filter part 41 Input level monitor part 45 Wind comparator part EQFL, EQFR; EQRL, EQRR Parametric equalizer L1, L2 Display element SFL, SFR; SRL, SRR; SW speaker

Claims (3)

[Claims] 1. A device for adjusting the parameters of the sound reproducing device so as to match desired acoustic characteristics in the acoustic space in which the sound reproducing device is used. Selecting means for selecting one of the signal sources and outputting the acoustic signal from the selected acoustic signal source; volume adjusting means for adjusting the level of the acoustic signal from the selecting means; An acoustic characteristic adjusting device comprising: frequency control means for adjusting the frequency characteristic of an acoustic signal; and phase control means for adjusting the phase of the acoustic signal from the frequency control means and outputting it to the acousticizing means. 2. The volume adjusting means, the frequency controlling means, and the phase controlling means are provided at least for each of the front left, front right, rear left, and rear right channels, and the volume adjusting means includes a left-right balance and a left-right balance. Adjusting the front-rear balance, the phase control means, corresponding to the distance difference from the acousticizing means provided for each channel to the listening position, the phase of the acoustic signal of the rear channel the acoustic signal of the front channel 2. The acoustic characteristic adjusting apparatus according to claim 1, wherein the acoustic characteristic adjusting apparatus shifts with respect to the phase. 3. In relation to the selecting means, a first display is displayed when the voltage level of the acoustic signal from the acoustic signal source is equal to or higher than a predetermined first voltage, and a second display higher than the first voltage is displayed. 3. The acoustic characteristic adjusting device according to claim 1, further comprising an input monitoring unit that performs a second display when the voltage is equal to or higher than the voltage.