JPH04299398A - On-vehicle audio device - Google Patents

Abstract

PURPOSE:To provide an optimum sound field space to each of different vehicles. CONSTITUTION:The on-vehicle audio device is provided with DSPs 4, 5, 61, and 63 which correct parameters such as the reverberation time of a digital audio signal, a microcomputer 10 which has plural data #1-#3 for giving specific sound field spaces to the different vehicles as data #D on the parameters, and a switch 13. The microcomputer 10 reads out the switching state of the switch 13. The microcomputer 10 loads one of the data #1-j$3 in the DSPs 4, 5, 61, and 63 according to the read switching state of the switch 13. The DSPs 4, 5, 61, and 63 correct the parameters of the digital audio signal according to the loaded data.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle audio system.

0002

2. Description of the Related Art When the interior of an automobile is viewed as an audio space, its volume is much smaller than that of a general room or listening room. Additionally, the noise level is high due to the sound of cars running.

[0003] For this reason, unique standing waves or resonances tend to occur inside the automobile, and the reverberation time and other characteristics tend to have unique frequency characteristics.

[0004] Therefore, when an audio device is installed in a car, the speakers are arranged as shown in FIG. 4, for example. That is, FIG. 4 is a plan view showing the interior of a passenger car, in which speakers FL and FR are provided on the left and right front doors, and speakers BL and BR are provided on the rear deck.

[0005] Then, the speakers FL and FR are supplied with mainly direct audio signals, and the speakers BL and BR are supplied with direct audio signals.
Audio signals such as early reflected sounds and reverberant sounds are mainly supplied to the rear speakers BL and BR, and the early reflected sounds and reverberant sounds from the rear speakers BL and BR create a sense of spaciousness similar to that in an ordinary room. Alternatively, a surround effect is further added.

[0006] Furthermore, the level and reverberation time frequency characteristics of the audio signals supplied to the speakers FL to BR are corrected in advance so that the reproduced sound does not have any peculiar characteristics when it is reproduced as sound in the automobile. There is. Furthermore, the frequency characteristics and level of the audio signal are corrected, taking into account auditory loudness characteristics and masking effects, so that the desired music can be heard comfortably even against the noise inside the car.

[0007] As described above, audio devices installed in automobiles perform various types of special signal processing compared to general audio devices.

[0008]

[Problems to be Solved by the Invention] However, the space inside a car varies depending on the type of car, and in particular, the space inside a car differs depending on the type of car.
By door sedan, two-door coupe, one box, etc.
significantly different.

[0009] Therefore, if an in-vehicle audio device is simply installed in a car, the effects of the reproduced sound from the rear speakers BL and BR will be quite different, and the user may feel uncomfortable. For example, in a large car with a relatively large interior space, if the same reverberant sound as a small car is reproduced from the rear speakers BL and BR, there will be too much reverberant sound and the reproduced sound will be unnatural. Moreover, in the opposite case, the reverberant sound is insufficient and a sufficient effect cannot be obtained.

[0010] Therefore, in multifunctional in-vehicle audio devices, the user is allowed to freely set parameters such as reverberation time, but in reality, there are many setting items, so the user cannot set all the settings. It is difficult to set the optimum value, and in most cases, the correction is insufficient or overcorrected.

[0011] The present invention aims to solve these problems.

0012

[Means for Solving the Problems] Therefore, in the present invention, the reference numerals of each part correspond to the embodiments described below. 61, 63, a microcomputer 10 having a plurality of data #1 to #3 that respectively provide predetermined sound field spaces for different vehicles as parameter data #D, and a switch 13. The switching state of the switch 13 is read, and one of the plurality of data #1 to #3 is sent to the DSP by the microcomputer 10 according to the read switching state of the switch 13.
4, 5, 61, 63, DSP4, 5, 61,
At step 63, the parameters of the digital audio signal are corrected according to the loaded data.

[0013]

[Operation] By setting switch 13, DSP4
, 5, 61, and 63 are set to optimal values for each vehicle, and an optimal sound field space for that vehicle is formed.

[0014]

[Embodiment] In Fig. 1, 1A to 1N indicate signal sources of audio signals such as an AM receiving circuit, an FM receiving circuit, a cassette tape player, and a CD player. The right channel audio signals are taken out and these audio signals are supplied to the switch circuit 2.

[0015] Also, 3 is an A/D converter, 4, 5, 6
1 and 63 are DSP (digital signal processor)
, 71 and 73 indicate D/A converters. And D.S.
P4, 5, 61, and 63 perform audio signal processing as described later, such as adding reverberation components and correcting frequency characteristics.

Furthermore, 10 indicates a microcomputer for system control, and this microcomputer 10 includes:
Various operation keys 11 are connected, and the microcomputer 10 controls the overall operation of this audio device according to the outputs of the keys 11.

[0017] Furthermore, the microcomputer 10 has DSPs 4, 5, 6
It has data #D of parameters such as program PRGM and reverberation time to be executed in 1 and 63, and in particular, as the data #D, for example, data #1 when the vehicle type is a sedan, data #1 when the vehicle type is a coupe, etc. It has data #2 and data #3 when it is a one-box.

Furthermore, a display device 12 for displaying the operating status of this audio device is connected to the microcomputer 10, and a switch 13 is also connected thereto. This switch 13 is switched depending on the type of vehicle in which this audio device is installed, and has switching positions of, for example, sedan, coupe, and one-box.

FIG. 2 shows that the switch 13 is provided on the front panel of the audio device together with the display device 12.
This is a case where the switching position of the switch 13 is graphically displayed on the display device 12. In addition, FIG.
In the case where the switch 13 is provided on the rear panel of the audio device, a symbol or the like indicating the switching position of the switch 13 is attached to the rear panel.

When this audio device is in operation, the switch circuit 2 is controlled by the microcomputer 10 in accordance with the output of the key 11, and the switch circuit 2 selects audio signals from the signal sources 1A to 1N. Then, this selected audio signal is supplied to the A/D converter 3 and A/D converted into a digital audio signal, and this digital signal is converted from DSP4 to DSP5 to DS.
The digital signal from the DSP5 is supplied to the DSP63.

In this case, the DSPs 4, 5, 61, and 63 perform the following processing on the audio signal. That is, the DSP 4 performs dynamics correction on the digital audio signal supplied thereto, and the DSP 5 controls the level and corrects frequency characteristics and the like.

Furthermore, the DSPs 61 and 63 add reverberation components and early reflected sound components, and the DSP 61 reduces the amount of addition.
Therefore, the proportion of the direct sound signal is increased, but
In the DSP 63, the amount of addition is increased, and therefore the ratio of signals of reverberant sound and early reflection sound is increased. Therefore, the signal from the DSP 61 becomes a signal of the reproduced sound from the front, and the signal from the DSP 63 becomes a signal of the reproduced sound from the rear.

[0023] Therefore, the signal from the DSP 61 is
The signal is supplied to a converter 71 and D/A converted into left and right channel analog audio signals, and these signals are supplied to speakers FL and FR through power amplifiers 81 and 82.

Further, the signal from the DSP 63 is supplied to the D/A converter 73 and D/A converted into left and right channel analog audio signals, and these signals are supplied to the speakers BL and BR through power amplifiers 83 and 84. be done.

[0025] In this case, the DSPs 4, 5, 61,
The contents of the processing in 63 are set by the microcomputer 10, and the sizes of parameters such as reverberation time are as follows:
It is set by the switching position of the switch 13.

That is, when this audio device is powered on, the microcomputer 10 starts processing, and the microcomputer 10 sends a program PR to the DSPs 4, 5, 61, and 63.
GM and data #D are each loaded.

However, in this case, the microcomputer 10 reads the switching position of the switch 13, and the data #1 to
Of #3, data corresponding to the switching position of the switch 13 is output from the microcomputer 10. For example, when the switch 13 is switched to the sedan position, data #1 for sedan is output from the microcomputer 10. Ru. Then, data corresponding to the switching position of the switch 13, in this case, data #1, is loaded into the DSPs 4, 5, 61, and 63 as data #D.

Subsequently, the loaded program PRGM is executed in the DSPs 4, 5, 61, and 63.
Signal processing as described above is performed.

At this time, the size of parameters such as reverberation time becomes the size according to the data #D loaded into the DSPs 4, 5, 61, and 63. For example, when the loaded data #D is data #1, the size is suitable for a sedan.

Therefore, when this audio device is installed in a vehicle, by setting the switch 13 to the switching position according to the type of vehicle, the optimum reverberation time etc. for the vehicle can be obtained, and the optimum reverberation time etc. for the vehicle can be obtained. An optimal sound field space can be created regardless of the type.

Furthermore, when the key 11 is operated, the data #D loaded into the DSPs 4, 5, 61, and 63 is changed by a minute amount in response to the key operation.
By operating the keys, the reverberation time etc. can be finely adjusted according to the user's preference.

[0032] In the above description, the switch 13 may be replaced by a jumper wire or the like since it is not switched frequently. In addition, signal sources 1A to 1N
When a digital audio signal can be extracted from the A/D converter 2, the digital audio signal may be bypassed by the A/D converter 2. Further, the number of DSPs 4, 5, 61, 63, connection relationships, processing contents, etc. can be changed according to the capabilities of the DSPs.

[0033]

[Effect of the invention] According to this invention, DSP4, 5, 61
, 63 data #D are prepared in advance for each type of vehicle, and among the data #D, the data corresponding to the vehicle is loaded into DSP 4, 5, 61, and 63 to correct the audio signal. , it is possible to obtain the optimal sound field space for each vehicle.

Furthermore, even if the user operates the keys 11 to adjust the effect, the adjustment range is limited, so the amount of audio signal correction may deviate greatly from the standard value, resulting in under-correction or over-correction. In addition, when necessary,
You can also reset it to its standard value at any time.

Furthermore, the manufacturer does not need to prepare a microcomputer 10 having data #1 to #3 for each type of vehicle, and the microcomputer 10 can be shared.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an example of the present invention.

FIG. 2 is a perspective view showing an example of a switch.

FIG. 3 is a perspective view showing another example of the switch.

FIG. 4 is a plan view showing an example of arrangement of speakers.

[Explanation of symbols]

1A~1N Signal source 2 Switch circuit 3 A/D converter 4, 5 DSP 10 Microcomputer 11 Operation keys 12 Display device 13 Switch 61, 63 DSP 71, 73 D/A converter 81-84 Amplifier FL, FR, BL, BR speakers

Claims (1)

[Claims] 1. A DSP that corrects parameters such as reverberation time for a digital audio signal, and a microcomputer that has a plurality of data that respectively provide predetermined sound field spaces for different vehicles as data for the parameters. , a switch, and the microcomputer reads the switching state of the switch,
According to the read switching status of the switch,
One of the plurality of data is loaded into the DSP by the microcomputer, and the DSP corrects parameters of the digital audio signal according to the loaded data.