JPH0822112B2 - Sound reproduction device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound reproducing device for improving sound characteristics.

2. Description of the Related Art In recent years, regarding the speaker reproduction of home audio, from reproduction of 2 speaker boxes to 4 speaker boxes,
There is a trend of improving the sound field, such as improving the sensation of reality by playing a larger number of speakers, such as a 6-speaker box. With regard to in-vehicle audio, with the recent hi-fi, there has been a change from the conventional 2-speaker playback system to 4-speaker, 6-speaker. Speaker playback system, including not only front seats but also rear seats
A uniform hi-fi sound is required.

An example of the above-described conventional sound reproducing device will be described below with reference to the drawings.

FIG. 16 shows an example of a conventional four-speaker system mounted on a vehicle, and is a view of the vehicle viewed from above. 1,1 is a front-seat speaker, 2,2 is a front seat, 3,3 is a rear-seat speaker, 4 is a rear seat, and 5 is a reproducing device for generating an electric signal to be reproduced. The speakers for passengers 1 and 1 and the speakers for passengers 3 and 3 are connected to each other, and the reproduced sound is output from the speakers 1 and 1 for passengers and the speakers 3 and 3 for passengers.

The operation of the sound reproducing device configured as described above will be described below.

The signal sent from the playback equipment is the speaker for the front passenger.
Playback is performed from 1,1 to front seats 2,2 and from rear seat speakers 3,3 to rear seats 4. As a result, the front seats 2, 2 and the rear seats 4 can each hear the reproduced sound with an appropriate capacity, and the front seats 2, 2 can be compared to the case of the two-speaker system having only the front-seat speakers 1, 1. There is no inconvenience that the volume is too high in the rear seat 4 at the proper volume.

Problems to be Solved by the Invention However, in the above-described configuration, due to the mounting conditions in the vehicle, the front-seat speaker 1,1, the rear-seat speaker 3,3
Both have a problem that sufficient speaker volume and airtightness cannot be obtained, resulting in insufficient reproduction of low frequency sounds.

Therefore, as shown in FIG. 17, using the rear tray 7 as 6 speakers, and adding woofer speakers 6 and 6,
The low-range sound is enhanced by the speaker volume and the airtightness of the rear tray 7. However, this method enhances the reproduction of low-frequency sounds, but on the other hand, there is a problem that the low-frequency sounds are too much in the rear seats 4 when adjusted to the proper low-frequency sounds in the front seats 2 and 2. .

In view of the above problems, the present invention provides a sound reproducing device capable of listening with the sound pressure level characteristics in the front seats and the sound pressure frequency characteristics in the rear seats aligned in the low frequency range. .

Means for Solving the Problems In order to solve the above problems, a sound reproducing device of the present invention is provided with front / rear speaker for reproducing an electric signal of a reproducing device and a phase of an output signal of the reproducing device. It consists of a phase shifter that changes within the reproduction band of the speaker and a woofer speaker whose reproduction frequency is set so as to reproduce the output signal of this phase shifter and cross over the reproduction cut frequencies of the front and rear seat speakers. It was done.

Effect The present invention, in the above-mentioned configuration, by combining the reproduced sound of the front / rear seat speakers that reproduce the original signal of the reproducing device and the reproduced sound of the woofer speaker that reproduces this phase change signal in the acoustic space, The sound pressure frequency characteristic of only the original signal can be changed, and the effect can be changed by the combination and arrangement of the original signal reproducing speaker and the phase change signal reproducing speaker, so the sound pressure frequency characteristic at each listening place can be changed. It is possible to control so that they are aligned.

First Embodiment Hereinafter, a sound reproducing device according to an embodiment of the present invention will be described.
This will be described with reference to the drawings. In FIG. 1, a vehicle-mounted sound reproduction device is shown, and a view of the vehicle from above is shown.
Reference numeral 8 indicates an outer shape of the car, 9 is a steering wheel, 10 and 10 are front seats, 11
Is a rear seat, 12 is a reproducing device such as a car radio and a car tape deck, 13 and 13 are front seat speakers, 14 and 14 are rear seat speakers, 5 is a woofer speaker, and 16 is a phase using a phase shifter. The means of change are shown.

With such a configuration, the signal of the reproduction device 12 that generates an electric signal corresponding to the sound to be reproduced is the speaker for front seat 13,1.
3 and the rear seat speakers 14, 14, respectively, and the woofer speaker 15 reproduces the signal whose phase has been changed through the phase changing means 16. In this example, the phase changing means 16 mixes the right and left signals to change the phase, and then sends the monaural signal to the woofer speaker 15. Front seat 1
In 0 and 10, since the low-frequency sound has little directivity to the playback sound of the front-seat speakers 13 and 13, the playback sound from the woofer speaker 15 is added for listening, so when the woofer speaker 15 is not present. In comparison, it is possible to extend the low frequency sound pressure frequency characteristics,
Similarly, in the rear seat 11, since the reproduced sound of the woofer speaker 15 is added to the reproduced sound of the rear seat speakers 14, 14, the sound pressure frequency characteristic in the low range can be extended. However, if the woofer speaker 15 is reproduced without passing through the phase changing means 16, the distance to the listening point is different. Therefore, as shown in FIG. 2, the reproduction level B of the woofer speaker 15 is set to the front seats 10, 10.
As a result of flattening the overall sound pressure frequency characteristic C by aligning the sound pressure level A of the front seat speakers 13, 13,
Then, since the low-frequency sound reproduction level B of the woofer speaker 15 becomes larger than the reproduction level D of the rear seat speakers 14, 14, the low-frequency level rises and the flat sound as shown in E as a whole. The pressure frequency characteristic cannot be obtained. However, if the signal from the woofer speaker 15 is used as a phase change signal and the amount of phase shift from the original signal is changed so as to approach + 180 ° or −180 ° from the crossover frequency to the lower range, The canceling effect between the reproduced sounds of the loudspeakers 14 and 14 and the woofer speaker 15 becomes large, and the canceling effect amount increases even though the reproduced sound level of the rear seat speakers 14 and 14 is attenuated from the crossover frequency. Therefore, the shaded portions A and B in FIG. 3 cancel each other out, and the sound pressure frequency characteristic F of the rear seat 11 is obtained by combining the reproduction level B of the woofer speaker 15 and the reproduction level D of the rear seat speakers 14, 14. Can be flat. On the other hand, front seats 10,10
Since the distance from the woofer speaker 15 is larger than in the case of the rear seat 11, the woofer reproduction level is low and the front seat 1
The influence of the phase shift of the woofer playback sound on 0 and 10 is small,
In addition, the phase also changes compared to when the rear seats are used, so it is possible to set the cancellation effect to the minimum. So the front seat 10,10,
Both the rear seats 11 can obtain flat sound pressure frequency characteristics as shown in FIG. 3, and uniform sound reproduction of the front seats and the rear seats is realized.

FIG. 4 is an example of actual measurement data obtained by carrying out the present invention on a passenger car, and A shows sound pressure frequency characteristics at the listening point in the front seat and B in the rear seat. In the front seat, the rear woofer speaker sound is added to the front speaker sound, whereas in the rear seat, the rear woofer speaker sound is attenuated by the rear seat speaker sound. The sound pressure characteristics of both the rear and rear seats are well balanced.

As for the installation location of the woofer speaker 15, as shown in FIG. 5, if the woofer speaker 15 is installed on the rear tray 17, the volume of the trunk room can be utilized, so that it is relatively easy to reproduce deep bass.

However, when the rear tray 17 is not provided, it is advisable to mount the box speaker 18 under the seat of the front seat 10 as shown in FIG. 6 or at the back of the center console 19 as shown in FIG.

Particularly in the case of the back of the center console 19, since the rear part and the left and right parts of the woofer speaker 15 are surrounded, efficient reproduction is possible due to the baffle effect. Further, when the rear-seat speakers 14, 14 are mounted on the rear tray 17, the woofer speaker 15 may be installed at the rear door position as shown in FIG.

Next, the phase changing means 16 is shown in FIG.
FIG. 11 shows an example of the delay circuit system.

FIG. 9 shows the frequency using the primary phase shift circuit of CR using the operational amplifier 20, resistors R, RG, RF and capacitor C. Then, as shown in Fig. 10, it can be delayed to 90 ° and then to 180 °, and with the necessary band for the woofer speaker 15,
The amount of phase delay can be set freely by combining the CR constant and other filters.
As shown in Fig. 11, a buffer amplifier 21 and a low-pass filter 2
2. With the circuit of the high-pass filter 23, the shifter 24, and the power amplifier 25, for example, the frequency characteristic can be set as shown in FIG. 12 and the phase characteristic can be set as shown in FIG. When mixed with the result original signal acoustically, is in the low range than f ₀ is added to the original signal, with increasing to a higher frequency than f _0, subtraction effect becomes larger.

FIG. 14 shows an example of a delay circuit system including a buffer amplifier 26, a high-pass filter 27, a delay circuit 28, a low-pass filter 29, and a power amplifier 30. By narrowing down to a necessary band and applying a constant delay t, for example, Assuming a 90 ° delay at f ₀ , at 2f ₀
It becomes a delay of 180 °, and although a gentle convergence characteristic to a constant value can not be obtained like when using the above phase shifter,
It is possible to obtain a sudden phase change as shown in FIG.

As described above, according to the present embodiment, the phase changing means 16 is used to combine the reproduced sounds of the original signal reproducing speaker and the phase changing signal reproducing speaker to realize a uniform sound pressure frequency characteristic for each listening place. be able to.

In the embodiment, the reproduction of the phase change signal is performed by the woofer speaker.
Although it was done in 15, this idea may be applied to other speakers. Also, the signal from the woofer speaker 15 is not the signal for the rear seat,
You can get it from the signal for the front seat. Further, the phase changing means 16 is further provided in the generator 12 that generates an electric signal, and the original signal, for example, a channel for the front passenger is moved and changed, and this and the phase change of the woofer which is the embodiment When combined with a signal, the effect can be further enhanced.

EFFECTS OF THE INVENTION As described above, according to the present invention, a reproducing device that generates an electric signal corresponding to a sound to be reproduced, a front-seat speaker and a rear seat that are provided in the vicinity of a front seat that reproduces the electric signal of the reproducing device. A sound reproducing device comprising a rear seat speaker provided in the vicinity, a phase shifter for changing a phase of an output signal of the reproducing device, and a woofer speaker for reproducing an output signal of the phase shifter, The woofer speaker is a woofer speaker having a characteristic that the reproduction cut frequency on the high frequency side crosses over the reproduction cut frequency on the low frequency side of the front and rear seat speakers, and the phase shifter is the original signal. The amount of change in phase from the high frequency side reproduction cut frequency of the woofer speaker and the low frequency side reproduction speakers of the front seat speaker and the rear seat speaker. The phase shifter has the characteristic of changing so that it approaches + 180 ° or −180 ° from the crossover frequency with the output frequency toward the low frequency side, and the reproduced sound of each speaker is synthesized in the acoustic space. It is now possible to control the sound pressure level in the low frequency range, and it is possible to control the sound pressure frequency characteristics at each listening point in both the front and rear seats, which is of great industrial value. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a sound reproducing device of the present invention, FIG. 2 is a sound pressure-frequency characteristic diagram of front seats and rear seats before improvement, and FIG. 3 is a rear seat according to the present invention. Sound pressure frequency characteristic diagram, FIGS. 4A and 4B are sound pressure frequency characteristic diagrams of front seats and rear seats when the sound reproducing device of the present invention is mounted on a passenger car, and FIGS. 5 to 8 are woofers of the present invention. FIG. 9 is an explanatory view showing a mounting example of a speaker, FIG. 9 is an electric circuit diagram showing an example of a phase changing means of the present invention,
FIG. 10 is a frequency characteristic diagram of the circuit, FIG. 11 is a block diagram showing another phase changing means, FIGS. 12 and 13 are frequency characteristic and phase characteristic diagrams, and FIG. 14 is still another phase changing means. FIG. 15 is a block diagram showing the same phase characteristic diagram, and FIGS. 16 and 17 are schematic configuration diagrams showing a conventional sound reproducing device. 10 …… Front seat, 11 …… Rear seat, 12 …… Playback device, 13 …… Speaker for front seat, 14 …… Speaker for rear seat, 15 …… Woofer speaker, 16 …… Phase change means, 17 ...... Rear tray, 18
…… Box speaker, 19 …… Center console.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Haruhi Yano, Inventor, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. Within the corporation (56) Reference JP 55-105500 (JP, A) JP 54-94001 (JP, A) JP 61-230600 (JP, A) Actual development JP 59-69594 (JP, U) Japanese Patent Sho 57-22480 (JP, B2)

Claims (5)

[Claims] 1. A reproducing device for generating an electric signal corresponding to a sound to be reproduced, a front seat speaker provided near the front seat for reproducing the electric signal of the reproducing device, and a rear seat provided near the rear seat. What is claimed is: 1. A sound reproducing device comprising a speaker for a seat, a phase shifter for changing a phase of an output signal of the reproducing device, and a woofer speaker for reproducing an output signal of the phase shifter, wherein the woofer speaker has a high frequency range. The reproduction cut frequency on the side is a woofer speaker having the characteristic of crossing over the reproduction cut frequency on the low frequency side of the front and rear speakers, and the phase shifter changes the phase from the original signal. Is a cross between the high-frequency side reproduction cut frequency of the woofer speaker and the low-frequency side reproduction cut frequencies of the front seat speaker and the rear seat speaker. An audio reproducing device as it goes to the low frequency side from Ba frequency, a phase shifter having varying characteristics so as to approach the + 180 ° or -180 °. 2. The sound reproducing device according to claim 1, wherein the mounting position of the woofer speaker is on the rear tray. 3. The sound reproducing device according to claim 1, wherein the mounting position of the woofer speaker is below the seat. 4. The sound reproducing device according to claim 1, wherein the mounting position of the woofer speaker is at the back of the center console. 5. The sound reproducing device according to claim 1, wherein the mounting position of the woofer speaker is at the rear door.