JP2971898B2 - Inspection method for multiple speakers - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting each speaker such as a car stereo having a plurality of speakers to check the operation of the speakers.

[Prior Art] Recent audio equipment uses a plurality of speakers having different output frequency bands in order to increase the fidelity during reproduction.

When a plurality of speakers are provided in this way, it is difficult for human hearing to determine which speaker has an abnormality even if any of the speakers has an abnormality. Particularly, in a car stereo or the like, since it is arranged in a narrow cabin, it may not be possible to even bring the ears close to the speaker. Therefore, when inspecting the operation of a car stereo on an assembly line of a vehicle body, it is extremely inaccurate if the inspection depends on human hearing.

On the other hand, there has been proposed a method of detecting an abnormality of a speaker using a measuring device without depending on hearing. For example,
Connect the measuring device to the speaker drive circuit and its transmission path,
There is a method of applying a signal of a predetermined frequency and checking the speaker from the state of the load impedance (Japanese Patent Laid-Open No.
No. 65100, JP-A-57-142100).

[Problems to be Solved by the Invention] However, in this method, a measuring device must be directly connected to the acoustic device, and connection and disconnection of the speaker or its peripheral circuit must be repeated for each measurement. No. Therefore, the workability of the measurement was extremely low.

SUMMARY OF THE INVENTION An object of the present invention is to realize a method for checking the operation of a plurality of speakers that can determine the state of each speaker without directly connecting to an audio device.

[Means for Solving the Problems] That is, the gist of the present invention resides in that a signal including a frequency band corresponding to the characteristics of each speaker at substantially the same volume level is output to an audio device including a plurality of speakers. At the same time, the sound is input to each speaker, and the volume generated by each speaker is measured using a measuring device that can display the magnitude relationship between the detected volume and the reference value, and the operation of each speaker is checked. A method for checking the operation of a plurality of speakers, characterized in that:

[Operation] A signal including a frequency band corresponding to the characteristics of each speaker at substantially the same volume level is simultaneously input to each speaker.
Therefore, sound is output from each speaker at substantially the same volume. On the other hand, the measuring device detects the volume,
It is possible to provide a display capable of determining the magnitude relationship between the detected volume and the reference value. This display may be directly indicated by a numerical value, or the sound volume may be compared with a reference value, and a lamp may be displayed when the sound volume is equal to or more than the reference value.

If the operation of the speakers is normal, the outputs of the speakers should be almost the same volume. For this reason, it is only necessary to bring the measuring device close to each speaker and check the display. If the volume is lower than the volume, the operation of the speaker can be determined to be abnormal, and if the volume is higher, it can be determined to be normal.

Example Next, an example of the present invention will be described. The present invention is not limited to these, and includes various embodiments in a range not departing from the gist thereof.

FIG. 1 is a block diagram for explaining an example of an apparatus used for a method for checking the operation of a plurality of speakers.

Here, the audio device 1 includes a speaker system 3 and a sound source system 5. The speaker system 3 includes three speakers: a woofer 3a, a squawker 3b, and a tweeter 3c. The woofer 3a is the bass frequency band, the squawker 3b
Has a frequency band of a middle-tone portion, and the tweeter 3c has a frequency band of a high-tone portion as an output characteristic. The sound source system 5 includes a power amplifier 5a and a cassette tape deck 5b. With this configuration, the cassette tape deck 5b
If you set and play a sound source tape in the power amplifier 5a
Outputs an acoustic signal to the speaker system 3. As a result, a sound having a pitch and volume corresponding to the sound source tape is output from each of the speakers 3a to 3c.

The measuring device 7 that captures the volume includes a microphone 9, a microphone amplifier 11, a volume detection level switch 13, a main amplifier
15, rectifier circuit 17, level measurement-battery check switch
19, comparator 21, judgment display LED23, regulator 2
5. It has a power switch 27 and a battery 29. FIG. 2 shows the appearance. When the sound wave emitted from the speaker system 3 reaches the microphone 9, the sound wave is converted into an electric signal by the microphone 9. This electronic signal is immediately amplified by the microphone amplifier 11. The volume level of the amplified electric signal is adjusted by passing through a volume detection level switch 13, reaches the main amplifier 15, and is further amplified. The main amplifier 15 has a sensitivity adjustment volume
15a is attached, and is adjusted in advance to have a predetermined sensitivity.

Next, the signal output as voltage oscillation from the main amplifier 15 is converted by the rectifier circuit 17 into a voltage signal corresponding to the amplitude. This voltage signal is input to the comparator 21 via the level measurement-battery check switch 19. At the same time, the reference voltage signal output from the regulator 25 is input to the comparator 21. The comparator 21 compares these two voltages, and applies a voltage to the determination display LED 23 to turn on the voltage when the voltage signal based on the sound wave exceeds the reference voltage, and turns off the light when the voltage signal does not exceed the reference voltage.

Accordingly, only when the sound volume exceeding the reference sound volume corresponding to the reference voltage is captured by the microphone 9, the judgment display LED 23 is turned on. Thus, by checking the lighting state of the determination display LED 23, it is possible to easily determine whether or not a sufficient volume is being emitted from the speaker system 3.

The measuring device 7 compares the detected sound volume with the reference sound volume,
It has only the function of simply displaying the result of which is larger or smaller by the judgment display LED 23, which is extremely simple. Therefore, as shown in FIG. 2, the measuring device 7 can be arranged in a configuration small enough to be placed on the palm of the hand. Of course, not only the lighting / non-lighting by the LED 23 but also the detected volume may be directly displayed by a numeral or a pointer.

The tip of the measuring device 7 is cut and forms an oblique cut surface 7a. The microphone 9 is arranged on the cut surface 7a.

Next, an embodiment of a method for checking the operation of a plurality of speakers using the above devices 1 and 7 will be described. It is assumed that the audio device 1 is a car stereo provided in the cabin of an automobile.

First, a cassette tape on which a reference sound has been recorded is set on the cassette tape deck 5b of the audio device 1. The reference sound is a sound including a sound in a frequency band corresponding to the characteristics of each of the speakers 3a to 3c at substantially the same volume level. For example, as shown in FIG. 3 (A), a sound having the same volume level from the low range to the high range may be used as the reference sound, or only each characteristic frequency band portion is synthesized as shown in FIG. 3 (B). May be used as the reference sound.

Next, the cassette tape deck 5b is operated, and each speaker is
Output sound from 3a to 3c. Due to the nature of the reference sound recorded on the cassette tape, the sound volume output from each of the speakers 3a to 3c should be detected as substantially the same sound volume if detected at the same distance.

Next, the measurer holds the measuring device 7 and operates the speakers 3a to 3c.
Microphone 9 on the protection net provided in front of
The parts are brought into contact and each volume is measured. The microphone 9 is brought into contact with the protection net by using the speakers 3a to 3a.
This is to make the detection distance for 3c substantially the same and further reduce the influence of other speakers. Incidentally, in the automobile assembly line for performing this measurement, noise received from the surrounding environment, that is, so-called background noise is also detected at the same time. Therefore,
Judgment display LED23 with reference volume generated in the background noise
The volume detection level switch 13 is adjusted so that lights up.

Further, since the microphone 9 is disposed on the oblique cut surface 7a, even when the microphone 9 is brought into contact with the protection net, the judgment display LED 23 is easily directed to the measurer. In particular, it becomes easy for the measurer to confirm the judgment display LED 23 with a shield-type speaker.

Here, for all speakers 3a to 3c, judgment display LED2
When 3 lights up, all the speakers 3a to 3c output a sound volume exceeding the reference sound volume. Since the recording of the cassette tape is set so that the same volume is output to each of the speakers 3a to 3c, it is understood that all the speakers 3a to 3c have no abnormality.

If at least one of the speakers does not light up the judgment display LED 23, it is determined that some obstacle exists in the speaker or a mechanism related thereto.

In this embodiment, since the operation of the speaker can be determined in this way, it is not necessary to directly connect the measuring device 7 to the acoustic device 1, and the measurement work can be improved. Further, since the measuring device 7 is compact, it is possible to make a measurement close to a speaker even in a narrow space such as in a car cabin. Therefore, accurate measurement can be performed without being affected by background noise, without increasing the output of the speaker.

In the present embodiment, a cassette tape is used as a sound source medium. Of course, if the audio device 1 is provided with a CD player, a CD on which a reference sound is recorded may be used. In addition, an appropriate sound source medium can be used according to the equipment of the audio device 1.

[Effects of the Invention] In the present invention, when checking the operation of a plurality of speakers, a signal containing a frequency band corresponding to the characteristics of each speaker at substantially the same volume level is simultaneously input to each speaker. The volume to be detected is detected by the measuring device,
A display is provided so that the magnitude relationship between the detected volume and the reference value can be determined.

For this reason, the abnormal operation of the speaker can be immediately identified from the fact that the sound volume is not the predetermined sound volume, so that the state of each speaker can be easily determined without directly connecting the measuring device to the acoustic device, thereby improving the measuring work. Can be achieved.

[Brief description of the drawings]

1 is a block diagram of an acoustic device and a measuring device used in one embodiment of the present invention, FIG. 2 is an external perspective view of the measuring device, and FIGS. 3A and 3B are recorded on a cassette tape. 6 is a graph showing distribution of frequency bands obtained. DESCRIPTION OF SYMBOLS 1 ... Acoustic apparatus, 3 ... Speaker system 3a ... Woofer, 3b ... Squawker 3c ... Tweeter, 5 ... Sound source system 5a ... Power amplifier 5b ... Cassette tape deck 7 ... Measuring apparatus, 9 ... … Microphone 23 …… Judgment display LED

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Yoshiya Tsurumi 1-19-3 Kamiochiai, Shinjuku-ku, Tokyo Inside Symphony Instruments Co., Ltd. (56) References JP-A-58-189525 (JP, A) JP-A-62-149300 (JP, A) JP-A-54-1015 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04R 29/00

Claims (1)

(57) [Claims] 1. An audio apparatus having a plurality of speakers, a signal containing a frequency band corresponding to the characteristics of each speaker at substantially the same volume level is simultaneously input to each speaker, and the volume generated by each speaker at this time. Is measured using a measuring device that displays the magnitude relationship between the detected volume and the reference value, and the operation of each speaker is checked.