JPH03271040A - Car sound device - Google Patents

Abstract

PURPOSE:To prevent increase in unpleasant feeling by lowering the generating level of a reverberation signal in a reverberation adding circuit or bringing it into nothing when the lowering of a receiving level is detected by a means for detecting that the receiving level in a radio receiving section is below its reference value. CONSTITUTION:An intermediate frequency amplifying circuit 4 of an FM radio receiving section 1 is additionally provided with a receiving state detecting circuit 9. When the circuit 9 detects the electric field strength of a received wave, and it becomes clear for its strength level to lower below a fixed threshold value, a control signal to bring a reverberation signal level into nothing is instantly generated to a reverberation adding circuit 6. When a receiving level is then recovered, the generating level of the reverberation signal is gradually heightened to its original level. In the circuit 6, the inputted original signal is transmitted to an amplifying circuit 7 as it is even when the receiving level remains below a reference level. Thus an unpleasant feeling such as a pause or distortion, which are caused by the lowering of the receiving level, is not exaggerated by the reverberation.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a vehicle audio device generally called a car stereo, and in particular, the present invention relates to a vehicle audio device generally called a car stereo. The present invention relates to a vehicle audio device that amplifies and outputs the amplified sound from a speaker.

(Prior art) In order to create a sound effect with a good sense of presence and spaciousness within a narrow 1-1 motion center, 11 Ryokawa systems using a reverberation adding circuit called a DSP (digital signal processor) have recently been developed. The sound equipment has been made longer. As is well known, DSP
The reverberation characteristics of a hall or the like with good acoustic effects are set, and a reverberation signal that is appropriately delayed from the input acoustic signal according to the acoustic characteristics is output along with the original signal. A signal from a signal source such as a tape player, a CD player, or a tuner is passed through the reverberation adding circuit to generate sound with reverberation from a plurality of speakers installed on the tabletop.

(Problems to be Solved by the Invention) When listening to FM broadcasts received by a tuner in a vehicle audio device as described above through a reverberation adding circuit,
When the electrolytic strength of the received wave temporarily decreases due to FM multipath distortion, etc., the muting circuit causes the sound to become interrupted and greatly distorted. However, since the reverberation adding circuit adds reverberation, the discomfort is significantly increased compared to the case without reverberation.

When receiving FM broadcasts in a car, the reception status fluctuates greatly as the vehicle is driven, so even if a stereo diversity reception system is used, the reception level may change temporarily due to FM multipath etc. A decline inevitably occurs.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to minimize the discomfort caused by the deterioration of the reception condition by the reverberation adding circuit when the user is enjoying music using the radio receiver as the source. An object of the present invention is to provide a vehicle acoustic device which prevents the sound from becoming louder.

(Means for Solving the Problems) Therefore, in the present invention, there is provided a means for detecting that the reception level in the radio receiving section has become below a standard, and a means for detecting that the reception level has decreased by the above-mentioned reverberation adding circuit. means for reducing or zeroing the generation level of the reverberant signal at the reverberation signal.

(Function) When listening to music or the like with good reception by the radio receiving section, the reverberation addition circuit functions at a normal speed and adds a reverberation signal with a set characteristic. However, when the reception level falls below the standard, the level of the reverberant signal generated in the reverberation adding circuit decreases or becomes zero, so although it is inevitable that the sound will be interrupted or distorted due to the decrease in the reception level, the discomfort will be reduced. This prevents the sound from becoming noticeably coarser due to reverberation.

(Embodiment) FIG. 1 shows a schematic configuration of a vehicle audio device according to an embodiment of the present invention, in which 1 is an FM radio receiving section, 6 is a reverberation adding circuit such as the above-mentioned DSP, and 7 is an acoustic signal generator. A low frequency amplification circuit (main amplifier) for amplifying the signal, and a speaker 8, which is not shown, is a stereo device with two left and right channels, and a large number of speakers 8 are installed at the front and rear of the car.

The FM radio receiving section 1 includes an antenna 2. ^Frequency amplification circuit 3.
Intermediate frequency amplification circuit 4. An FM demodulation circuit 5 is provided, and a demodulated acoustic signal is outputted from a speaker 8 via a reverberation adding circuit 6 and a one-width circuit 7. As described above, the reverberation addition circuit 6 adds an appropriately delayed reverberation signal to the input acoustic signal and outputs the added signal.

A receiving state detection circuit 9 is attached to the intermediate frequency amplitude circuit 4 of the FM radio receiving section 1. This detection] 111 path 9 detects the electrolytic intensity of the received wave, and supplies the following control signal to the reverberation adding circuit 6 when the intensity level falls below a predetermined threshold. When the reception level becomes below the threshold value, a control signal is generated to the reverberation adding circuit 6 to immediately reduce the reverberation signal level to zero, and when the reception level becomes open later, the generation level of the reverberation signal is changed. Gradually increase to the original level. Note that the reverberation addition circuit 6 transmits the input original signal as it is to the amplifier circuit 7 even during a period when the reception level is below the standard.

(Effects of the Invention) As explained in detail above, in the vehicle audio device according to the present invention, when listening to radio broadcasting using the reverberation adding circuit, when the reception level decreases due to multipath, etc. Since the generation level of the reverberant signal is automatically reduced or becomes zero, the reverberation does not exaggerate the unnatural feeling of sound interruption or distortion due to a reduction in the reception level.

[Brief explanation of drawings]

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

Claims (1)

[Claims] For vehicles, which includes a reverberation addition circuit that adds and outputs a suitably delayed reverberation signal to an input acoustic signal, and amplifies the acoustic signal from a radio receiver via the reverberation addition circuit and outputs it from a speaker. The acoustic device includes means for detecting that a reception level in the radio receiving section has become below a standard, and a generation level of a reverberation signal in the reverberation adding circuit when a decrease in the reception level is detected by the means. A vehicle acoustic device characterized by comprising: means for reducing or reducing the sound to zero.