JPH08130794A - Center channel signal playback device - Google Patents

Abstract

(57) [Abstract] [Purpose] When reproducing multi-channel audio such as a movie using a video reproducing device such as a television, it is possible to easily match the image on the TV screen with the sound image for center channel reproduction. It is intended to provide a center channel signal reproducing device. [Structure] A sound pressure level in a specific band of approximately 4 kHz or more of a main speaker provided below a video reproduction device is attenuated. In addition, a sub-speaker configured to reproduce the specific band is installed above the video reproducing device such that the main axis differs from the main axis of the main speaker by 90 ° or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a center channel audio reproducing apparatus, which is an audio reproducing apparatus used in combination with a video reproducing apparatus.

[0002]

2. Description of the Related Art In recent years, in general households, a video reproducing apparatus such as a television with a large screen (hereinafter abbreviated as TV),
It has become more and more popular to play a powerful movie in combination with an audio player which plays multi-channel audio signals such as Dolby Pro Logic.

FIG. 6 shows the arrangement of a video reproducing device and a speaker device for reproducing multi-channel audio. In the figure, a TV 5 is installed in front of a viewer 6, and speaker devices 2 and 3 for reproducing front left and right audio signals are installed on both left and right sides of the TV 5. Further, in this example, the speaker device 1 ′ for reproducing the center channel signal is installed in the center and the upper side of the stand 7 on which the TV 5 is mounted,
Further, two speaker devices 4 for reproducing surround signals are installed behind the viewer 6.

The speaker device 1'is mainly installed for reproducing the dialogue, and the speaker device greatly improves the sense of localization of the dialogue.

[0005]

However, in the above-mentioned conventional structure, as shown in FIG.
Since the sound is reproduced from the speaker device 1'installed under V5, the sound image can be located at the position indicated by B in general. On the other hand, since the image is reproduced by the TV 5 on the speaker device, the position of the sound image and the position of the image are different, which gives a viewer a feeling of strangeness.

In order to solve such a problem, as shown in FIG. 8, it is conceivable to install two speaker devices 1 "for reproducing a center channel signal in close proximity to both left and right sides of the TV 5. With such a configuration, the center channel signal is radiated from the left and right speaker devices 1 "and combined, and a sound image can be formed in the central portion of the two speaker devices 1" like C. Therefore, the positions of the image and the sound image can be changed. Matched playback is possible.

However, in the case of the configuration shown in FIG. 8, when the viewer listens on the bisector of the two speaker devices 1 ", the audio reproduction of the center channel matching the image is possible. When listening in different directions, the frequency characteristics are disturbed due to the distance difference between the two speakers and the viewer 6 ′, and the sound quality changes significantly.
When listening to the TV 5 toward the left side like the viewer 6'in the figure, the sound image is shifted to the left side like C ',
There is a problem that the positions of the image and the sound image are misaligned.

As a method of solving such a problem, a method of disposing two speaker devices 1a ″ above and below the TV 5 as shown in FIG. 9 can be considered. If the speaker device 1a ″ is disposed as described above. Since the sound image can be at the D position,
It becomes possible to reproduce the sound image and the image at the same position. Also,
Even when viewed at a position deviated from the front of the screen in the left-right direction, the sound quality does not change and the positions of the sound image and the image do not shift as in the conventional example of FIG. An example of an audiovisual reproducing apparatus in which speakers for reproducing a center channel signal are built in above and below the screen as in the configuration of FIG. 9 is disclosed in Japanese Patent Laid-Open No. 4-27060.
No. 0 publication. In the example of the above-mentioned document, various signal processings are combined, but the purpose is to match the position of the sound image with the position of the screen.

However, the above-mentioned configuration has a problem that when the viewing position changes vertically, the sound quality changes as in the conventional example of FIG. Further, there is a problem that a large installation space is required on both the upper side and the lower side of the TV 5.

In view of the above conventional problems, it is an object of the present invention to provide a center channel signal reproducing apparatus for center channel reproduction, which can easily match the image on the TV screen with the sound image. .

[0011]

In order to solve the above-mentioned conventional problems, the center channel signal reproducing apparatus of the present invention comprises a main speaker provided below the video reproducing apparatus and a main speaker 4K.
Signal attenuating means for attenuating a signal level in a specific band of Hz or more, a sub-speaker installed by an installing means on the upper side of the video reproducing device, and a signal in a band substantially the same as the specific band set by the signal attenuating means. Bandpass means for
The main speaker is connected to the signal attenuating means to attenuate the sound pressure in the specific band, and the sub-speaker is connected to the band passing means to reproduce the specific band. Therefore, the main axis of the sub-speaker is installed so as to be different from the main axis of the main speaker by approximately 180 °.

Further, the signal attenuating means is approximately 6.3 kHz.
It is composed of a dip circuit centered on z.

Further, means for varying the volume level of the sub speaker is provided.

[0014]

According to the present invention, the direct sound from the main speaker has almost no signal in a specific band of 4 kHz or more due to the sound pressure attenuating means. Therefore, it is difficult for the viewer to recognize the sound source position of the reproduced sound in the vertical direction. As a result, the sound image is strongly attracted to the screen by the effect of the visual superiority, and it is possible to perform reproduction in which the sense of coincidence between the sound image and the image is obtained. Furthermore, the sub-speaker emits a signal in the specific band, which is insufficient in the sound emitted from the main speaker due to being attenuated by the signal attenuating means, and is reproduced and complemented as an indirect sound by using, for example, the rear wall of the TV. , It is possible to reproduce the center channel signal without any sound quality discomfort.

Further, the signal attenuating means is approximately 6.3 kHz.
If the dip circuit is set in the vicinity of z, it is particularly easy to obtain a feeling of coincidence between the sound image and the image.

Further, since the volume level of the sub speaker can be changed, for example, the distance between the TV and the rear wall is small,
The volume of the sub-speaker can be adjusted depending on the installation condition, such as when the reflected sound level becomes high.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1A is a diagram showing a center channel signal reproducing apparatus according to an embodiment of the present invention. In the figure, 1a is a main speaker, which is installed in the center and upper side of the stand 7 of the TV 5. Reference numeral 1b denotes a sub speaker, which is installed in the recessed portion of the upper shape of the TV 5 so that the main axis faces the rear direction. In this embodiment, the main speaker 1a is connected to the input terminal 1e via the dip circuit 1c as the signal attenuating means, and the sub speaker 1b is connected to the input terminal 1e via the bandpass circuit 1d. The center frequencies of the dip circuit 1c and the bandpass circuit 1d are set to about 6.3 kHz in this embodiment. The operation of the attenuator V1 connected between the sub speaker 1b and the band pass circuit 1c will be described later.

Up to now, many experiments concerning sound source recognition have been conducted and various reports have been made. For example, Fujiki, Masutani, Maruyama et al., "On the frontal virtual sound image in stereophonic" (Electrical Acoustics Research Society, EA81-16, 198).
1), Kurosawa, Tsugi, Yamaguchi et al., "On Head Transfer Function and Directional Discrimination Ability" (Proceedings of the Acoustical Society, Vol. 38, 4).
3.66. Qp, 1982) describes that sound source recognition in the median plane, that is, in the vertical direction of the front, is performed by a change in auditory frequency characteristics by the head or auricle at high frequencies of about 4 kHz or higher. There is. Therefore, it can be said that in the case of the sound source having no high frequency signal, the vertical position of the median plane is difficult to be recognized.

Referring to these documents, as shown in FIG. 3, a trial listening experiment was conducted with five speakers SP installed on the front midline of the subject T. As the sound source, one octave band eliminate noise as shown in FIG. 4 is used, and the center frequency f
Each combination of several kinds of signals with different c and five speakers SP was presented at random. The subject
The numbers were used to indicate from which position of the five speakers the presented sound was heard.

FIG. 5 shows the results of the above experiment, in which the number of responses (vertical axis) at a position different from the position of the presented sound source is taken as the center frequency fc of the band elimination noise.
It is summarized for each (horizontal axis). From the figure, it can be seen that the number of erroneous answers is large at fc 5 kHz or higher.
It can be seen that the largest number of them is when fc is 6.3 kHz.

From this result, it was found that the vertical sound source recognition becomes ambiguous unless there is a high frequency component above about 4 kHz. In particular, it has been found that it is very difficult to recognize the sound source in the vertical direction when there is no signal in the band centered around 6.3 kHz. In addition, as a result of a trial listening experiment with a real source,
It was found that removing the signal component of 4 kHz or more facilitates the coincidence between the sound image and the image. Furthermore, it has been found that, in the case of the speaker device in which only the signal near 6.3 kHz, which has the most false answers in the above-mentioned listening experiment, is removed by the dip circuit, a sense of coincidence between the sound image and the image is easily obtained.

Komiyama, Nakabayashi, Nikaido et al., "Basic Experiment on Interaction between Stand-up TV Image and Stereo Sound Image-Vertical Sound Image Localization-" (Hearing Study Group, H-8)
1-33, 1981), it is widely known that visual information has priority over auditory information.
That is, the sound image tends to be attracted to the visual direction in which the user is gazing. This effect becomes more significant as the sound source position is ambiguous. It is considered that the sense of coincidence between the sound image and the image obtained when the speaker device in which the signal component of about 4 kHz or more is removed is used is due to the above visual priority effect.

The present invention has been made by utilizing the above-mentioned auditory psychological characteristics. To determine the vertical position of the sound source, 4 kHz or more, especially. 6.3kH
Although a signal component in the vicinity of z is required, the sound wave radiated from the center signal reproducing device of FIG. 1 (a) is as shown in FIG. 1 (b).
As shown in FIG. 3, the radiated sound (arrow A) from the main speaker 1a, which is mainly composed of direct sound, is generated by the dip circuit 1c.
There is almost no sound near 6.3 kHz (frequency characteristic M in FIG. 2). Therefore, in terms of hearing, it is very difficult to recognize the sound source in the vertical direction of the sound emitted from the main speaker 1a. On the other hand, the radiated sound from the sub-speaker having a frequency characteristic as shown by S in FIG. 2 is reflected by the rear wall of the TV 5 as shown by an arrow A ′ and reproduced as an indirect sound. Original sound source position is difficult to recognize. As a result, it becomes difficult to recognize the sound source of the reproduced sound, the position of the sound source in the vertical direction becomes ambiguous, the sound image and the image match due to the visual priority effect, and the reproduced sound excellent in sound quality can be obtained.

However, in the above configuration, when the rear wall of the TV 5 is close, the sound pressure of the signal component radiated from the sub speaker 1b becomes too high, the sound image as a whole rises too high, and a high frequency range is produced in terms of sound quality. It will be too much. On the contrary, when the distance to the rear wall of the TV 5 is too large, there is a problem that the signal component from the sub speaker 1b is insufficient and the high frequency range is insufficient in terms of sound quality.

Therefore, by providing the attenuator V1, the volume of the sub speaker 1b can be adjusted. Therefore, the sound quality can be adjusted by adjusting the indirect sound level from the sub speaker 1b reaching the viewer 6 by adjusting V1.

Needless to say, a so-called multi-way system in which both the main speaker 1a and the sub speaker 1b are composed of a plurality of units may be used.

[0028]

As described above, the center channel signal reproducing apparatus of the present invention attenuates the sound pressure level of the main speaker provided below the TV at a specific band of about 4 kHz or more, particularly at about 6.3 kHz, and By reproducing the specific band as an indirect sound by the upper sub-speaker, not only the center channel signal in which the sound image and the image match can be reproduced, but also the reproduced sound excellent in sound quality can be obtained. Also, since most of the center channel signals are reproduced from the main speaker, the sound quality does not change significantly even if the listening position moves up and down. Further, as the sub-speaker, a speaker unit having a small diameter can be used, as long as it can reproduce a high sound range. That way, it won't stand out much on the TV.

Further, if the volume of the sub-speaker can be varied, the sound quality can be adjusted according to the installation condition while the sound image and the image are matched.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a center channel signal reproducing device and radiated sound waves according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a sound pressure frequency of the speaker device of the present invention.

FIG. 3 is a layout diagram showing a method of a vertical sound source recognition experiment.

FIG. 4 is a frequency characteristic diagram of a signal used in a vertical sound source recognition experiment.

FIG. 5 is a diagram showing a result of a vertical sound source recognition experiment.

FIG. 6 is a state of use of a conventional speaker device for reproducing a center channel signal.

FIG. 7 is an explanatory diagram of a sound image formed by the conventional example.

FIG. 8 is an explanatory diagram of a sound image formed by another conventional example.

FIG. 9 is an explanatory diagram of a sound image formed by still another conventional example.

[Explanation of symbols]

1a Main speaker 1b Sub-speaker 1c Dip circuit 1d Band pass filter 1e Input terminal V1 Attenuator 1'Conventional center channel speaker installed under the video playback device 1 "Center installed on the left and right of the conventional video playback device Channel speaker 1a "Conventional center channel speaker installed above and below the video playback device 2 Left channel speaker 3 Right channel speaker 4 Surround channel speaker 5 Television 6, 6'Audience 7 TV stand

Claims (3)

[Claims] 1. A main speaker provided below the video reproduction device, a signal attenuating means for attenuating a signal level in a specific band of approximately 4 kHz or more, and a sub-speaker installed by an installation means above the video reproduction device. And a band pass unit that passes a signal in a band substantially the same as the specific band set by the signal attenuating unit, and the sound pressure attenuating unit is connected to the main speaker to attenuate the sound pressure in the specific band. The sub-speaker is configured to connect the band pass means to reproduce the set specific band, and the main axis of the sub-speaker is different from the main axis of the main speaker by approximately 180 °. Center channel signal reproducing device configured to be installed as described above. 2. The signal attenuating means of a specific band is approximately 6.3k.
The center channel signal reproducing apparatus according to claim 1, wherein the center channel signal reproducing apparatus is configured by a dip circuit having a center frequency near Hz. 3. The center channel signal reproducing apparatus according to claim 1, further comprising means for varying the volume level of the sub speaker.