JPH01175405A - Car audio device - Google Patents

Abstract

PURPOSE:To eliminate the dissatisfaction of listeners in low tone range by varying the correction quantity of frequency characteristics of an equalizer amplifier corresponding to variation in noise level with the traveling speed of an automobile and adjusting the frequency characteristics of a reproduction sound automatically. CONSTITUTION:An equalizer controller 5 monitors the traveling speed of the automobile at all times with a vehicle speed sensing signal inputted from a vehicle speed sensor 4, selects ideal frequency characteristics of an audio signal corresponding to the current traveling speed, and outputs an ideal frequency characteristic determination signal. The equalizer amplifier 6 corrects the frequency characteristics of the audio signal from the program source according to the determination signal and its output is reproduced by a speaker through a control amplifier 7 and a power amplifier 8. Consequently, the reproduction tone quality is so corrected as to surpass the noise level corresponding to the current traveling speed at all times and thus held constant to the listener side.

Description

DETAILED DESCRIPTION OF THE INVENTION To Industrial Application Field 2-7 The present invention relates to a car audio device for reproducing audio signals without impairing the audible sound quality while the car is running.

BACKGROUND ART FIG. 4 shows the configuration of a conventional car audio device.

In FIG. 4, this conventional audio system includes an audio amplifier including an equalizer amplifier 1, a control amplifier 2, and a power amplifier 3.

The small voltage of the audio signal from the program source is amplified to a certain level by the equalizer amplifier 1, and at the same time its frequency characteristics are corrected. The output of this equalizer amplifier 1 is voltage amplified by a control amplifier 2 to the extent that it can drive a power amplifier 3, and the output of this control amplifier 2 is power amplified by a power amplifier 3, and the speaker is operated by the output, and the above-mentioned The audio signal is now played as audio.

Problems to be Solved by the Invention However, in the above-mentioned conventional car audio device,
Due to the fact that the level of noise such as engine noise, running noise caused by contact between tires and road surface, and wind noise increases as the speed of the vehicle increases, the audibility of the vehicle while the vehicle is running increases. There was a problem that the sound quality was impaired.

The above-mentioned noise contains a lot of low-frequency components, so as the speed of the car increases,
The low frequency range of the audio reproduced by the car audio device is lost to the noise, making it difficult to hear, making the listener feel that the bass is lacking.

The present invention is intended to solve these conventional problems, and aims to provide an excellent car audio device that can maintain a constant audible sound quality regardless of the speed at which the vehicle is traveling. Means for Solving the Problems In order to achieve the above object, the present invention provides a vehicle speed sensor that detects the traveling speed of an automobile, and a system that receives a traveling speed detection signal from the vehicle speed sensor and uses the vehicle speed sensor to detect the traveling speed of the vehicle. Equalizer control that determines the ideal frequency characteristics that the audio signal from the program source should have in order to ensure that the sound quality reproduced from the speakers remains constant regardless of the noise level that changes with the speed of the vehicle. The equalizer control device controls the correction operation of the equalizer amplifier so that the frequency characteristics of the audio signal from the program source are corrected to the ideal frequency characteristics determined by the equalizer control device.

Effect: Therefore, according to the present invention, the frequency characteristics of the reproduced sound can be automatically adjusted in response to changes in the noise vibration caused by changes in the running speed of the vehicle, so that the frequency characteristics of the reproduced sound can be automatically adjusted when the vehicle is stopped, running at a constant speed, changing gears, etc. The audible sound quality can be maintained constant regardless of the driving condition of the car. Therefore, if the output level of the bass range, which is difficult to hear due to noise while driving, is increased and reproduced, the result will be 5 ＼.

This makes it possible to eliminate the lack of low pitch feeling that was given to the listeners.

Embodiment FIG. 1 is a schematic block diagram showing the configuration of a car audio system according to an embodiment of the present invention, FIG. 2 is a graph showing frequency versus noise level inside a running vehicle, and FIG. 3 is a graph showing the noise level in a running vehicle. It is a graph showing the ideal frequency characteristics that an audio signal should have depending on the driving speed.

In FIG. 1, 4 is a vehicle speed sensor, which senses the traveling speed of the automobile and outputs a traveling speed sensing signal.

Reference numeral 5 designates an equalizer control device, and the equalizer control device 5 is configured to receive a travel speed detection signal from the vehicle speed sensor 4, and is adapted to adjust the audible sound quality in response to the noise level in the vehicle. In order to maintain the frequency constant regardless of the speed of the vehicle, ideal frequency characteristic data that should be applied to the audio signal from the program source is preset. This equalizer control device 5 is configured to calculate the traveling speed of the automobile represented by the traveling speed detection signal from the vehicle speed sensor 46, (
Alternatively, the corresponding noise level in the vehicle) (second
At the same time, the ideal frequency characteristic of the audio signal corresponding to the noise level (see Figure 3) is selected and determined from the above preset data, and the determined data is included. It outputs an ideal frequency characteristic determining signal. As shown in FIG. 3, the ideal frequency characteristic is such that as the traveling speed of the vehicle increases, the rate of increase in the components in the bass range increases.

6 is an equalizer amplifier, 7 is a control amplifier, and 8 is a power amplifier, which constitute an audio amplifier. The audio signal from the program source and the ideal frequency characteristic determination signal from the equalizer control device 5 are input to the equalizer amplifier 6, and the equalizer amplifier 6 amplifies the small voltage of the audio signal to a certain level of thickness. , based on the above decision signal, so that the ideal frequency characteristic expressed by this is achieved7.
- It has a function to correct the frequency characteristics of the audio signal. The control amplifier 7 receives the output of the equalizer amplifier 6 and amplifies the voltage to such an extent that it can drive the power amplifier 8. The power amplifier 8 amplifies the output of the control amplifier 7 and outputs the This activates the speaker and reproduces the audio signal.

Next, the operation of the above embodiment will be explained.

According to the above embodiment, the equalizer control device 5 constantly monitors the traveling speed and speed of the vehicle based on the vehicle speed detection signal inputted from the vehicle speed sensor 4, and selects the ideal frequency characteristic of the audio signal corresponding to the current traveling speed. , outputs an ideal frequency characteristic determining signal. The equalizer amplifier 6 corrects the frequency characteristics of the audio signal from the program source according to the determined signal, and its output is reproduced from a speaker via a control amplifier 7 and a power amplifier 8. As a result, the reproduced sound quality is always corrected to overcome the noise level corresponding to the current traveling speed, and is kept constant for the listener, so that the listener does not feel a lack of bass.

For example, if you are currently driving in the central area, the noise level will be shown as Ml in Figure 2.
The equalizer control device 5 selects the frequency characteristic shown as M2 in FIG.
The equalizer amplifier 6 corrects the frequency characteristic of the audio signal from the program source so that it becomes the frequency characteristic shown in FIG. 3 M2.

When the speed is accelerated from a medium speed to a high speed, the noise level becomes the one shown as Hl in FIG. Upon receiving the ideal frequency characteristic determination signal, the equalizer amplifier 6 determines the frequency characteristic of the audio signal, which is expressed as H2 in FIG.
The correction is made so that the frequency characteristic is expressed as follows.

9...-2 Also, when the speed is decelerated from medium speed to low speed, the equalizer control device 5 selects the frequency characteristic shown as L2 in FIG. 3 that corresponds to the noise level shown as Ll in FIG. 2. The equalizer amplifier 6, which has received the ideal frequency characteristic determination signal, corrects the frequency characteristic of the audio signal so as to have the frequency characteristic shown as L2 in FIG.

As described above, according to the above embodiment, the vehicle speed sensor 4 senses the traveling speed of the automobile, and the equalizer control device 5 selects the ideal frequency characteristic that allows the reproduced sound to overcome the noise level corresponding to the current traveling speed. Then, the selection signal is input to the equalizer amplifier 6, and the correction operation of the correction amount equalizer amplifier 6 is controlled to correct the frequency characteristics of the audio signal to the selected frequency characteristics. Corresponding to the change in the noise level caused by the change, the amount of correction of the frequency characteristics in the equalizer amplifier 6 changes, and the frequency characteristics of the reproduced sound are automatically adjusted. This has the effect that the audible sound quality can be maintained constant regardless of the situation.

According to the above-mentioned embodiment, the ideal frequency characteristics selected by the equalizer control device 5 are such that as the traveling speed of the car increases, the components in the bass range increase. The shortage will be resolved.

Effects of the Invention As is clear from the above embodiments, the present invention changes the frequency characteristic correction amount in the equalizer amplifier in response to changes in the noise level accompanying the traveling speed of the vehicle, and automatically adjusts the frequency characteristics of the reproduced sound. As a result, the audible sound quality can be maintained constant regardless of the speed of the vehicle, such as when the vehicle is stopped, traveling at a constant speed, or changing gears. Therefore, the output level of the low frequency range, which is difficult to hear due to noise during driving, is increased and reproduced, so that the lack of low frequency feeling given to the listeners can be resolved.

[Brief explanation of the drawing]

11...7 Fig. 1 is a schematic block diagram of a car audio device according to an embodiment of the present invention, Fig. 2 is a graph of frequency versus noise level in the vehicle while driving, and Fig. 3 corresponds to the running speed of the car. FIG. 4 is a schematic block diagram of a conventional car audio device. 4...Vehicle speed sensor, 5. Equalizer control device, 6. Equalizer amplifier, 7. Control amplifier, 8.. Power amplifier.

Claims (1)

[Claims] (1) A vehicle speed sensor that senses the traveling speed of the vehicle and outputs a traveling speed detection signal; and a noise level that changes the quality of the sound reproduced from the speaker based on the traveling speed sensing signal according to the traveling speed of the vehicle. an equalizer control device that determines the ideal frequency characteristic that an audio signal from a program source should have in order to be held constant regardless of the frequency, and outputs the ideal frequency characteristic determination signal; A car audio device comprising: an audio amplifier including an equalizer amplifier that corrects the frequency characteristics of an audio signal from the program source.