JP2009100317A - Multi-channel signal reproduction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that when a reproduction sound of a surround channel interferes with a reproduction sound from a front channel speaker driver, a sense of clear localization cannot be obtained, similarly to reflection on the wall or the like. <P>SOLUTION: A multi-channel signal reproduction apparatus includes: a first speaker box to which a speaker driver is mounted for front L channel, front center channel and front R channel reproduction and which is installed at a lower side of a television screen; a second speaker box to which a surround L channel and surround R channel speaker driver is mounted and which is installed at an upper part of the television screen; and a virtualizer which performs signal processing on a reproduction signal inputted to the surround L channel and surround R channel speaker driver and localizes a sound source at a place different from the space where the surround L channel and surround R channel speaker driver is installed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multi-channel signal reproducing apparatus used when reproducing a DVD or terrestrial digital broadcast.

  A so-called home theater system that reproduces a multi-channel surround signal such as 5.1 channel or 6.1 channel is widely used in general households. This system basically reproduces each channel signal by an independent speaker for each channel. Therefore, in the case of 5.1 channel signal reproduction, it is necessary to arrange three speakers for the front L channel, front center channel, and front R channel in the front, and two speakers for the surround L channel and the surround R channel in the rear. There is. In addition, a subwoofer is often required for bass reproduction.

On the other hand, the applicant of Patent Document 1 processes the surround L channel signal and the surround R channel signal with a virtualizer using a head-related transfer function (hereinafter referred to as HRTF), and installs two signals installed at the front of the listener. We have proposed a home theater system that can reproduce the sound image at a position where there is no speaker by playing it from other speakers. According to such a system, it is possible to construct a home theater system simply by installing one speaker having five speaker drivers and a subwoofer in front of the listener. Therefore, it is not necessary to install a large number of speakers in the room, and it is possible to obtain a simple system that does not route many wires in the room.
JP 2005-102063 A

  In the system using the above-described virtualizer, the filter constant of the head-related transfer function is determined on the assumption that the listener's ear is located at a predetermined position. Therefore, for example, when the reflected sound from the wall or ceiling of the room reaches the listener's ear, sound other than the sound calculated by the head-related transfer function enters the listener's ear, and the sense of localization of the surround channel is impaired. .

  Further, the surround L channel signal and the surround R channel signal are emitted from the speaker driver to the space and propagate through the air to reach the listener's ear. As disclosed in Patent Document 1, the surround L channel signal and the surround R channel signal are transmitted. When the speaker driver for the R channel signal and the speaker driver for the front channel are stored in one speaker box, the speaker driver for the surround L channel signal and the surround R channel signal and the speaker driver for the front channel are adjacent to each other. Therefore, the reproduced sound emitted from the speaker driver for the surround L channel signal and the surround R channel signal immediately interferes with the reproduced sound from the speaker driver for the front channel. As a result, it is not possible to obtain a clear orientation as in the case where there are reflections on the walls and the like.

  In order to solve the above-described problems, the present invention provides three speaker drivers for reproducing front L channel, front center channel, and front R channel signals, and front L channel, front center channel, and front R channel speakers. A first speaker box 1 installed on the lower side of the TV screen, a speaker driver for playing surround L channel and surround R channel, and a speaker driver for surround L channel and surround R channel are attached. The signal processing is performed on the playback signal input to the second speaker box installed at the top of the TV screen and the speaker driver for the round L channel and surround R channel, And a virtualizer for localizing the sound source in a place different from the place where the speaker driver for the L channel and the surround R channel is installed.

  According to the present invention, the reproduced sound of the surround channel subjected to the fine signal processing reaches the listener without interfering with the reproduced sound of the front channel, so that the reproduced sound of the surround channel with a clear sense of localization can be obtained. I can do it.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.

  Examples of the present invention will be described below. In the apparatus of the present invention, speaker drivers 3 to 5 for reproducing the front L, center and front R channels of the 5.1 channel signal are accommodated in the base speaker box 1. 1 to 3 are a top view, a front view, and a perspective view of the base speaker box 1, and partition walls 6 and 7 are provided inside the base speaker box 1 in order to form a total of three sealed cavities. . A total of 6-core speaker cables for the three speaker drivers 3 to 5 are shown as one speaker cable 8. The front surface of each speaker driver 3 to 5 is provided with a fabric saran net 9 having good air permeability so that the speaker drivers 3 to 5 cannot be directly seen from the outside.

  Considering that the base speaker box 1 is at a position lower than the height of the listener's ear, the vibration axes of the speaker drivers 3 to 5 are arranged so as to face upward by about 30 degrees. Further, the L channel speaker driver 3 and the R channel speaker driver 5 are arranged to face each other with respect to the center channel speaker driver 4. Due to this outward facing arrangement, the reproduced sound from the speaker drivers 3 and 5 is radiated into the space in opposite directions, and thus has the same effect as when the speaker drivers 3 and 5 are arranged at a large interval. And contributes to the expansion of the stereo image.

  Speaker drivers 11 and 12 for reproducing the surround L and surround R channels are housed in a top speaker box 10. 4 to 6 are a top view, a front view, and a perspective view of the top speaker box 1, and a partition wall 13 is provided inside the top speaker box 10 in order to form a total of two sealed cavities. A total of four-core speaker cables for the two speaker drivers 11 to 12 are illustrated as one speaker cable 14. In addition, the fabric saran net | network 15 is provided in the front surface of each speaker driver 11 and 12 like the above-mentioned.

  FIG. 7 is a circuit block diagram of a home theater system 20 including an amplifier that drives the above-described speaker drivers 3 to 5, 11, and 12. The digital data from the DVD drive 2 controlled by the microcomputer 25 is input to the 5.1 channel decoder 22, and includes a front L, a front center, a mechanical unit such as an optical pickup and a turntable, and various servo circuits and data demodulation circuits. The front R, surround L, surround R channel, and subwoofer channel signals are decoded. The digital signals of the front L, front R, and front center channels are input to the digital amplifier 23.

  On the other hand, the surround L and surround R channel signals are input to the virtualizer 24. For example, the virtualizer 24 includes a filter having a filter characteristic that provides an impulse response so that a reproduced sound can be heard from the rear left side of the listener even if the surround L channel signal is reproduced by a speaker installed on the front side of the listener. Various filter characteristics are adjusted on the assumption that the distance between the speaker box 10 and the listener is about 2 m. Generally, this filter coefficient is called a head related transfer function (HRTF), and the input signal has position information by performing a convolution calculation process. Since the configuration of the virtualizer 24 itself is well known in the art and is not directly related to the present application, its detailed description is omitted.

  The output of the virtualizer 24 is input to the digital amplifier 23. The surround L and surround R channel signals are reproduced by two speaker drivers 11 and 12, respectively, and are not reproduced by one speaker driver for each channel.

  During playback of a 2-channel source such as a CD, the 5.1 channel decoder 22 outputs an L channel signal to the terminal that output the front L channel signal, and an R channel signal to the terminal that outputs the front R channel signal. And the low frequency signal contained in both channels is output to the subwoofer channel signal.

  The signal of each channel converted into a PWM signal by the digital amplifier 23 passes through a low-pass filter (hereinafter referred to as LPF) 26 to be converted into an analog signal, and then is output to each speaker driver 3 to 5, 11, 12 and the subwoofer 27. Is done.

  FIG. 8 is a diagram showing a state in which the base speaker box 1 and the top speaker box 10 are installed indoors. The television 31 is installed on the television stand 32 so as to face the listener 33. A base speaker box 1 is installed in the center of the TV stand 32 in the width direction of the TV. In addition, the top speaker box 10 is installed at the center of the TV 31 in the width direction of the TV. In recent years, televisions have been thinned such as liquid crystal televisions and plasma televisions, and a mount adapter 40 shown in FIG. 9 is used to install the top speaker box 10 on the top of the television. In the illustrated embodiment, the subwoofer 27 is installed on the TV stand 32. However, since it is difficult for a human to determine where the low-frequency sound is heard, There is no need to install it before.

  By installing the base speaker box 1 at the center in the width direction of the television 31, the voice of the announcer in the news program played by the center channel speaker driver 4 and the line of the movie can be localized at the center in the width direction of the screen. it can.

  The various filters of the virtualizer 24 are designed such that the distance between the top speaker box 10 installed on the television 31 and the ear of the listener 33 is 2 m. Therefore,

  FIG. 9 is a side view of the state in which the mount adapter 40 is attached to the upper part of the television 31. The mount adapter 40 includes a base plate 41 mounted on the upper portion of the television 31 and two arm portions 42 provided on the pace plate 41 so as to be rotatable. The arm portion 42 can be fixed to the base portion 41 with a screw 43 so that the angle can be adjusted, and the base plate 41 can be placed horizontally above the television 31 by adjusting the mounting angle according to the thickness of the television 31 or the like. . The top speaker box 10 is placed on the base plate 41, and the top speaker box 10 is fixed to the base plate 41 with screws (not shown). Note that a surface fastener (not shown) or the like may be attached to the surface of the base plate 41 that contacts the upper surface of the television 31, and the base plate 40 may be fixed to the upper surface of the television 31.

  Since the top speaker box 10 that reproduces the surround channel is disposed at a separate position independently of the base speaker box 1 that reproduces the front channel, the reproduced sound of the surround channel reproduced by the speaker drivers 11 and 12 is the front channel. It is possible to reach the listener's ear without being interfered with the reproduced sound. As a result, the reproduced sound image of the Sarand channel generated through various filters using the head-related transfer function is reproduced from the top speaker box 10 disposed in front of the listener, but from the side to the rear of the listener. Clear localization is possible.

  Further, the fact that the top speaker box 10 for reproducing the surround channel is installed on the television 31 inevitably means that the top speaker box 10 is installed at a certain distance from the floor. As a result, if the top speaker box 10 is separated from the wall by about 1.5 m or more, it is possible to reduce the influence of unnecessary reflected sound not only from the wall but also from the floor. The position information of the surround channel is not affected.

  In the above-described embodiment, the independent speaker driver 4 is provided for the center channel. However, the present invention is not limited to this, and the base speaker box 1 includes the front L channel and the front R channel. It is also possible to regenerate the center channel signal by these two speaker drivers.

  FIG. 10 is a circuit block of the home theater system 50 in the second embodiment, and the same members as those in the first embodiment shown in FIG. The front L channel signal from the 5.1 channel decoder 22 is connected to one input terminal of the first adder 28. The front R channel signal from the 5.1 channel decoder 22 is connected to one input terminal of the second adder 29. The center channel signal is connected to the other input terminal of each of the first and second adders 28 and 29.

  With this circuit configuration, the center channel signal can be reproduced by the speaker drivers 3 and 5 together with the front L channel signal and the front R channel signal, and the base speaker box 1 can be miniaturized.

  In the case where the television is not a thin television but a cathode ray tube type television, since there is a certain level of flat surface on the top of the television, the top speaker box 10 may be placed on the cathode ray tube type television without using the mount adapter 40. Is possible.

  In the above-described embodiment, the various filters of the virtualizer 24 are designed with the distance between the top speaker box 10 and the listener 33 being 2 m. However, the present invention is not limited to this, and the filter is designed at an arbitrary distance. Various modes can be taken without departing from the spirit of the present invention.

The top view of the base speaker box 1. FIG. The front view of the base speaker box 1. FIG. The perspective view of the base speaker box 1. FIG. The top view of the top speaker box 10. FIG. The front view of the top speaker box 10. FIG. The perspective view of the top speaker box 10. FIG. FIG. 3 is a circuit block diagram of the home theater system 20. The figure which shows the state in which the base speaker box 1 and the top speaker box 10 were installed indoors. The side view of the state in which the mount adapter 40 was attached to the upper part of the television 31. FIG. FIG. 6 is a circuit block diagram of a home theater system 20 in the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base speaker box 3 Front L channel speaker driver 4 Center channel speaker driver 5 Front L channel speaker driver 10 Top speaker box 11, 12 Surround channel speaker driver 20 Home theater system 24 Virtualizer 27 Subwoofer 31 TV 40 Mount adapter

Claims (5)

Three speaker drivers 3 to 5 for reproducing front L channel, front center channel, and front R channel signals,
A first speaker box 1 to which speaker drivers 3 to 5 for the front L channel, the front center channel, and the front R channel are attached and installed on the lower side of the television screen;
Speaker drivers 11 and 12 for reproducing the surround L channel and the surround R channel;
A second speaker box 10 to which speaker drivers 11 and 12 for the surround L channel and the surround R channel are attached and installed at the top of the television screen;
The playback signals input to the round L channel and surround R channel speaker drivers 11 and 12 are signal-processed, and the location is different from the location where the round L channel and surround R channel speaker drivers 11 and 12 are installed. A multi-channel signal reproducing apparatus comprising a virtualizer 24 for localizing a sound source. At least two speaker drivers for playing the front L channel, front center channel, and front R channel;
A first speaker box 1 to which the speaker driver is attached and installed at the lower side of the TV screen;
A second speaker box 10 to which speaker drivers 11 and 12 for surround L channel and surround R channel are attached and installed at the top of the television screen;
The playback signals input to the round L channel and surround R channel speaker drivers 11 and 12 are signal-processed, and the location is different from the location where the round L channel and surround R channel speaker drivers 11 and 12 are installed. A multi-channel signal reproducing apparatus comprising a virtualizer 24 for localizing a sound source.   The multi-channel signal reproducing apparatus according to claim 1 or 2, wherein the first and second speaker boxes (1 and 10) are arranged at substantially the center in the width direction of the television screen.   3. The first speaker box 1 is attached to the first speaker box 1 so that a vibration axis of a speaker driver for reproducing the front L channel, the front center channel, and the front R channel is directed upward. The multi-channel signal reproducing apparatus as described.   3. The first speaker box 1 is attached to the first speaker box 1 so that the vibration axes of the speaker drivers for reproducing the front L channel and the front R channel face each other. Multi-channel signal playback device.