JP2000089772A - Acoustic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and precisely perform proper adjustment for acoustic characteristics of respective seat positions in an automobile cabin for a car stereo device. SOLUTION: A DSP 20 for audio is provided with variable delay circuits 21-24 and parametric equalization circuits 25-28, and processes an input audio signal to supply it to plural speakers 3LF-3RB in automobile cabin 2. The manufacture, beforehand, controls the delay circuits and the equalization circuits matched with respective seat positions of respective types of car, and writes the control data of the delay circuits and the equalization circuits corresponding to the optimum acoustic characteristics in the automobile cabin in a semiconductor memory 44 to supply it. The user assembles the semiconductor memory in the car stereo device, and reads out the control data corresponding to required seats, and controls the filter characteristics, etc., of the DSP to obtain the required acoustic characteristics without requiring operation for measuring and adjusting the acoustic characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acoustic device suitable for mounting on a passenger car, for example.

[0002]

2. Description of the Related Art Conventionally, a tape or a compact disk (C) mounted on a dashboard of a passenger car or the like is used.
An audio device for reproducing music from a recording medium such as D), a so-called car stereo device, has been awarded.

In general, in a car stereo system, four speakers are provided on the left and right sides of a front portion and a rear portion in a vehicle compartment.

[0004]

However, since the interior of the vehicle is a small enclosed space, its acoustic characteristics are not always good. For example, as shown in FIG. 4, the sound pressure level has a large peak in a low frequency region. And there are dips.
These are greatly affected by standing waves.

In FIG. 4, a simulation is performed on a 1/3 scale model of an actual vehicle compartment, and the frequency is converted into the frequency of the actual vehicle compartment.

Conventionally, techniques suitable for adjusting acoustic characteristics in a vehicle cabin include, for example, removal of a standing wave disclosed in Japanese Patent Application Laid-Open No. 9-327086 and Japanese Patent Application Laid-Open No. 10-161.
For example, optimization of a delay time disclosed in Japanese Patent No. 667 is known.

[0007] However, the conventional techniques as described above all require a microphone for measurement, which takes a long time for measurement, and has the disadvantage that the measurement position of the microphone must be specified for adjustment. there were.

In the latter case, there is a problem that a high-speed arithmetic unit is required to obtain the frequency of the standing wave, which increases the cost, and that the measurement and the automatic adjustment take a long time, resulting in poor usability.

Further, the acoustic characteristics of the vehicle interior are shown in FIGS. 4A and 4B.
As can be understood from the above, not only does the seat position differ, but also the same seat position differs between the left and right ear positions,
For example, there is a problem that appropriate adjustment cannot be performed for other seats based on measurement data of only the driver's seat.

That is, when a large number of measurement points (6 rows and 7 columns in the figure) are set in a modeled vehicle interior as shown in FIGS. 5A and 5B, for example, as shown by black circles in FIG. 5B. 4A, the sound pressure distribution at each measurement point at the peak frequencies fa, fb, fc due to the standing wave is shown in FIG.
A, B, and C show the results, respectively.

In FIGS. 6A, 6B and 6C, the vicinity of the center of each figure corresponds to the position of the head of the occupant in the front seat.
The right end of each figure corresponds to the position of the head of the occupant in the rear seat. The sound pressure is low in the dark black portions, and high in the thin portions.

The sound fields shown in FIGS. 6A, 6B and 6C are:
In each case, a single speaker is used as shown in FIG. 5B.

As described above, the sound field in the passenger compartment is greatly affected by standing waves, and it is in principle difficult to make appropriate adjustments in each seat by measuring only one point.

In view of the foregoing, it is an object of the present invention to provide an audio device capable of easily performing appropriate adjustment by signal processing on the acoustic characteristics of a vehicle interior.

[0015]

In order to solve the above-mentioned problems, an audio apparatus according to the first aspect of the present invention provides a multi-channel audio signal corresponding to a plurality of speakers arranged at predetermined positions in a vehicle cabin. A signal processing device comprising: a plurality of delay circuits and an equalization circuit corresponding to the plurality of speakers; a plurality of delay circuits and an equalization circuit corresponding to the plurality of speakers; Means, a memory means in which control data for controlling the characteristics of the plurality of delay circuits and the equalizing circuit to adjust the acoustic characteristics in the vehicle cabin are written in advance, and And control means for controlling the characteristics of the delay circuit and the equalization circuit of the signal processing means.

In the audio device according to the first aspect of the present invention, control data such as an equalization circuit supplied from the manufacturer of the audio device and controlled to adjust the acoustic characteristics for each vehicle type is transmitted to the user. Side, it is possible to control the signal processing means of the audio device easily and accurately without using the user's side for calculation for measuring and adjusting the acoustic characteristics, and to control the signal processing means of the audio device. The sound field in the room is adjusted, and desired acoustic characteristics can be obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an acoustic device according to the present invention will be described below with reference to FIGS.

[Structure of Embodiment] FIG. 1 shows the structure of an embodiment of the present invention.

In FIG. 1, the interior of a cabin 2 of an automobile 1
Four loudspeakers 3L on each side of the front and rear
F, 3RF, 3LB, 3RB are provided. These speakers 3LF to 3RB are so-called genuine products.

On the other hand, the optical disk D is an optical pickup (PU) 1 of an optical disk reproducing unit (so-called deck) 10.
1, the spindle motor 12
And the optical pickup 11 is moved in the radial direction of the disk D by the feed motor 13.

Although not shown, the optical pickup 11 includes a laser diode as a light source, an optical system including an objective lens, a photodetector for receiving light reflected from the disk D, and a light detector in the optical axis direction of the objective lens. A focus actuator for controlling the position is built in.

The reproduced RF signal from the optical pickup 11 is supplied to an RF signal processing circuit 14 through a preamplifier circuit (not shown). In the RF signal processing circuit 14, a speed error signal VE for servo control, A tracking error signal TE and a focus error signal FE are generated, and both are supplied to the servo control circuit 15.

An output corresponding to the speed error signal VE and the tracking error signal TE is supplied to the spindle motor 12 and the feed motor 13 from the servo control circuit 15, and an output corresponding to the focus error signal FE is output to the optical pickup 11. Are supplied to the focus actuator.

A reproduction signal output from the RF signal processing circuit 14 is a demodulation DSP (digital signal processor).
The signal is supplied to the audio signal DSP 16 and subjected to processing such as error correction.

The control information output from the demodulation DSP 16 is supplied to a reproducing section control circuit 17. Under the control of the control circuit 17, the servo control circuit 15 controls the optical pickup 11, the spindle motor 12, The motor 13 is controlled.

The reproducing unit control circuit 17 controls the mechanical system of the optical disk reproducing unit 10 and the system control circuit 4
The control information is also exchanged with the control unit 1.

On the other hand, the audio DSP 20 corresponds to the aforementioned speakers 3LF, 3RF, 3LB, and 3RB.
Four variable delay circuits 21, 22, 23, 24 respectively
And parametric equalizers 25, 26, 27, 28
Are connected in cascade.

Each of the delay circuits 21 to 24 is composed of a digital filter, and each of the parametric equalizers 25 to 28 is composed of a plurality of digital band filters (not shown). The parametric equalizers 25 to 28 can appropriately set the coefficient value of each digital band-pass filter so that the gain increase / decrease and the sharpness Q
Are controlled in a predetermined range.

The demodulation DSP 16 supplies the left channel digital audio signal to the first and second variable delay circuits 21 and 22 in common, and the right channel digital audio signal outputs the third and fourth variable delay circuits. It is supplied to the circuits 23 and 24 in common.

Then, the parametric equalizer 25,
The four-channel digital audio signals output from 26, 27, and 28 are converted into four-channel analog audio signals by a DA converter (not shown), and the four amplifiers 31, 32, 33, and 34 are provided. Through
The signals are supplied to the four speakers 3LF, 3LB, 3RB, and 3RF, respectively, and sound is emitted from these speakers 3LF to 3RB.

Further, a control signal is supplied from the system control circuit 41 to each of the delay circuits 21 to 24 and each of the equalizers 25 to 28 in order to adjust respective characteristics.

The above configuration is the same as that of a conventional car stereo device.

In this embodiment, an operation key group 42 and a display 43 are connected to a system control circuit (microcomputer) 41 and an external memory 44.
Is connected.

The memory 44 is a semiconductor memory.
The audio D is adjusted so that the sound field in the cabin 2 is adjusted to an optimum state according to the manufacturer, model, year, etc. of the automobile 1.
Each delay circuit 21 to 24 and each equalizer 2 of SP20
Control data (coefficients of the digital filter) for adjusting the characteristics of 5-28 is provided by the manufacturer of the car stereo device.
It is stored in advance and supplied in a form incorporated in a car stereo device.

[Adjustment of the sound field in the vehicle interior of the embodiment]
The adjustment of the sound field in the passenger compartment according to the embodiment of the present invention will be described with reference to FIGS.

As described above, in the external memory 44 of this embodiment, the sound field is adjusted to an optimum state according to the manufacturer, model, model, etc. of the automobile 1 equipped with the car stereo device. Control data is stored in advance.

As described above, since the acoustic characteristics in the vehicle compartment differ depending on the seat position, the external memory 44 stores control data corresponding to the driver's seat, the passenger seat, and the left and right rear seats.

On the manufacturer side of the car stereo device, the acoustic characteristics of the vehicle interior in the frequency domain and the space as shown in FIGS. 4 and 6 are actually measured for each representative vehicle type of the automobile manufacturer. The characteristics of the delay circuits 21 to 24 and the equalizers 25 to 28 of the audio DSP 20 of the car stereo device mounted on the actual vehicle are controlled for each seat so that the measured acoustic characteristics are adjusted to the optimum state. Delay circuits 21 to 21 corresponding to the obtained characteristics.
24 and the coefficient values of the digital filters of the equalizers 25 to 28 are selected as control data and stored in the memory 44.
Is written to.

Further, the acoustic characteristics of the vehicle interior are almost determined by the shape of the vehicle interior, similarly to the acoustic characteristics of the vehicle interior.
For similar models, use a workstation, etc.
The sound characteristics are simulated, and the audio D is adjusted so that the simulated sound characteristics are adjusted to an optimum state.
SP20 delay circuits 21-24 and equalizers 25-
28 characteristics are simulated for each seat, and the corresponding coefficient value of each digital filter is selected as control data and written to the memory 44.

When the car stereo device is mounted on an automobile, the external memory 44 described above is incorporated in the car stereo and connected to the system control circuit 41.

When adjusting the sound field in the vehicle interior, the user
When, for example, a key for selecting the adjustment of the driver's seat in the operation key group 42 is operated, under the control of the system control circuit 41, the control data corresponding to the driver's seat is read from the external memory 44, and the audio data is read out. The signal is sent to the DSP 20, and the coefficient values of the digital filters of the delay circuits 21 to 24 and the equalizers 25 to 28 are set.

In the audio DSP 20, the delay circuits 21 to 24 and the equalizer 2 are the same as those adjusted in advance by the manufacturer of the car stereo device.
The characteristics of 5-28 are instantaneously reproduced.

Thus, the sound field in the driver's seat is adjusted, and desired acoustic characteristics can be obtained.

For example, as shown in FIG. 2, the sound pressure level at the driver's seat (left ear) is optimized, and peaks and dips due to standing waves before sound field adjustment are suppressed.

As shown in FIGS. 3A, 3B, and 3C, the peak frequencies fa, fb, and fc of the standing waves before the sound field adjustment are performed.
The sound pressure distribution in the passenger compartment (see FIG. 4 described above) is also significantly flattened.

In the other seats, the sound field in the passenger compartment is adjusted in the same manner as described above, and desired acoustic characteristics can be obtained.

As described above, in this embodiment, the setting data of the equalizer and the like adjusted so as to adjust the acoustic characteristics for each vehicle model, which is supplied from the manufacturer of the car stereo device and written in advance in the semiconductor memory, is supplied. , On the user side,
By using it as it is, on the user side, there is no need for calculation for measurement and adjustment of acoustic characteristics, and easily and
The DSP of the car stereo device can be accurately adjusted, and the sound field in the vehicle compartment can be adjusted to obtain desired acoustic characteristics.

[Disc Playback of Embodiment] After the sound field in the vehicle compartment is adjusted as described above, the operation keys 42
When the reproduction key is operated, the operation contents are displayed on the display 43 and the reproduction of the disk D is executed.

Specifically, the disk D is rotated, and the optical pickup 11 emits light to focus. Next, after the above-described servo processing is performed, the recording signal is read and the digital data is reproduced.

In this case, first, the TOC (table of contents) information is read, and based on this information, the reproduction of the music (track) is executed, and the corresponding reproduction data is stored in the audio DS.
Delay circuit 2 sent to P20 and adjusted as described above
In each of the equalizers 1 to 24 and the equalizers 25 to 28, predetermined acoustic processing is performed.

The four-channel audio signals output from the equalizers 25 to 28 and converted into analog signals are supplied to the speakers 3LF to 3RB through the amplifiers 31 to 34, respectively. , And the desired acoustic characteristics are realized.

[Other Embodiments] In the above-described embodiment, the control data from the manufacturer is written in the external semiconductor memory and supplied in a form incorporated in the car stereo device. The flash R0M may be provided, and the optical disk reproducing unit may be compatible with the CD-ROM, and control data from the manufacturer may be supplied in the form of a CD-ROM and written into the flash R0M.

The control data from the manufacturer may be supplied in the form of a magnetic medium such as a floppy disk, or may be downloaded to a hard disk of a computer or the like via an Internet line and stored in the flash ROM 0.
It is good also as a form which writes in M etc.

In the above-described embodiment, the genuine speaker is used. However, when the loudspeaker is replaced from a genuine one, it is sufficient to prepare a characteristic suitable for the replaced speaker.

Further, control data can be automatically set in accordance with parameters such as the number of passengers and the output ratio between front and rear.

[0056]

As described above, according to the first aspect of the present invention, there is no need for the user to perform an operation for measuring and adjusting the acoustic characteristics, and the signal processing of the acoustic device can be easily and accurately performed. The means can be adjusted so that the sound field in the cabin is adjusted and the desired acoustic characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of an acoustic device according to the present invention.

FIG. 2 is a diagram showing frequency characteristics in a vehicle cabin according to the embodiment of the present invention.

FIG. 3 is a diagram for explaining sound field adjustment according to the embodiment of the present invention.

FIG. 4 is a diagram showing frequency characteristics in a vehicle interior for explaining the present invention.

FIG. 5 is a conceptual diagram showing a form of a cabin for explaining the present invention.

FIG. 6 is a diagram showing a sound pressure distribution in a vehicle interior for explaining the present invention.

[Explanation of symbols]

1 ... automobile, 2 ... cabin, 3LF, 3RF, 3LB, 3R
B: speaker, 10: optical disk playback unit (deck), 1
1: optical pickup, 12: spindle motor, 13
... feed motor, 14 ... RF signal processing circuit, 15 ... servo control circuit, 16 ... demodulation DSP, 17 ... reproduction unit control circuit,
Reference Signs List 20 DSP for audio (digital signal processor), 21-24 variable delay circuit, 25-28 parametric equalizer circuit, 31-34 amplifier circuit, 41 system control circuit (microcomputer), 42 operation key group , 43 display, 44 external memory, D optical disk,

Claims (1)

[Claims] 1. An audio apparatus for supplying audio signals of a plurality of channels respectively corresponding to a plurality of speakers arranged at predetermined positions in a cabin of an automobile, comprising: a plurality of delay circuits corresponding to the plurality of speakers; Signal processing means including an equalization circuit for processing the input audio signals of the plurality of channels to adjust the acoustic characteristics of the vehicle interior; and controlling the characteristics of the plurality of delay circuits and the equalization circuit to control the vehicle. A memory unit in which control data for adjusting the acoustic characteristics of the room is written in advance; and a control unit for controlling characteristics of the delay circuit and the equalization circuit of the signal processing unit based on the control data of the memory unit. An acoustic device having control means.