JP2003264893A - Sound signal transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound signal transmission system with a small speaker cable loss, at a low installation cost with excellent sound quality. <P>SOLUTION: This invention provides the sound signal transmission system wherein a plurality of audio units each comprising a speaker box incorporating a speaker and a power amplifier placed in the vicinity of the speaker box are placed at various locations, a central controller placed at a different place transmits a digital audio signal and a digital control signal through one or more cables, and the power amplifiers are bridge-connected. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio broadcasting device in a large-area building or outdoors, and a speaker box with a built-in speaker and its proximity to the speaker box by a central control device that sends out digital audio signals and digital control signals. A plurality of audio units consisting of a power amplifier arranged in a plurality, with one or a plurality of cables bridge-connected between the plurality of power amplifiers,
The present invention relates to an audio signal transmission device that individually controls a plurality of audio units, a plurality of groups, or a total number of audio units.

[0002]

2. Description of the Related Art In an audio broadcasting apparatus in a large area building or outdoors, a central control unit and a plurality of power amplifiers are arranged in a control room, and a plurality of speaker boxes each having a built-in speaker are installed in different places. The power amplifier and the speaker are connected individually with the speaker cable. Therefore, it was necessary to lay a power amplifier with a large output in consideration of the loss of the speaker cable and a thick speaker cable capable of flowing a large current for the number of installed speakers. Further, since the analog transmission is apt to be affected by noise and the like, the equipment cost enormously, and the sound quality is not good.

[0003]

In view of the present situation described above, a plurality of audio units each including a speaker box having a built-in speaker and a power amplifier arranged in the vicinity of the speaker box are installed in each place, and the center of the other place is installed. By sending digital audio signals and digital control signals from the control device with one or more cables, and connecting each power amplifier in a bridge, a voice signal transmission device with low speaker cable loss, low installation cost, and good sound quality can be provided. provide.

[0004]

Means for Solving the Problems As a result of intensive research in view of the above, the present inventor has solved this problem by the following means. (1) In an audio broadcasting device in a large-area building or outdoors, a plurality of audio units each including a speaker box containing a speaker and a power amplifier arranged in the vicinity of the speaker box, and a plurality of the audio units. A central controller for transmitting a digital audio signal for controlling a power amplifier and a digital control signal, and a bridge between the plurality of power amplifiers for transmitting a signal transmitted from the central controller to the power amplifiers of the plurality of audio units An audio signal transmission device comprising one or a plurality of connected cables.
That is, in an audio broadcasting apparatus in a large-area building or outdoors, a plurality of audio units each including a speaker box containing a speaker and a power amplifier having a decoder / encoder arranged in the vicinity of the speaker box; Centralized with a digital audio mixer for sending out a digital audio signal to be output to the power amplifier of the audio unit and a controller for sending out a digital control signal for controlling the audio mixer and for sending and receiving a status signal sent out from the power amplifier A controller and the digital audio signal sent from the digital audio mixer,
The digital control signal sent from the controller and the status signal sent from the power amplifier are bridge-connected between the plurality of power amplifiers for transmitting and receiving between the power amplifiers of the plurality of audio units, An audio signal transmission device comprising one or a plurality of connection cables for transmitting and receiving a digital audio signal and the digital control signal and status signal.

(2) In an audio broadcasting device in a large area building or outdoors, a plurality of audio units each including a speaker box containing a speaker and a power amplifier arranged in the vicinity of the speaker box, and the plurality of audio units. Sending of a digital audio signal and a digital control signal for controlling the power amplifier of the unit, a central control unit for sending and receiving the status signal sent from the power amplifier, and a signal sent and received by the central control unit for the plurality of audio units. An audio signal transmission device comprising one or a plurality of cables bridge-connected between the plurality of power amplifiers for transmission to a power amplifier.

(3) The central control device is provided with a mechanism for coding a digital control signal sent from the central control device into a user data area of a digital audio signal and sending the coded signal with a single cable. The audio signal transmission device according to item (1). (4) The central control unit and the power amplifier code the digital control signal sent by the central control unit and the status signal sent by the power amplifier in the user data area of the digital audio signal and send / receive it with one cable. The audio signal transmission device according to the item (2), which is provided with a mechanism.

(5) Two cables dedicated to the central control unit and the power amplifier for the digital control signal sent by the central control unit and the composite signal of the status signal sent by the power amplifier, and the digital audio signal, respectively. It is characterized by comprising a mechanism for transmitting and receiving by (2)
The audio signal transmission device according to the item. (6) The central controller and the power amplifier send a digital audio signal sent by the central controller, a digital control signal, and a status signal sent by the power amplifier,
The audio signal transmission device according to the item (2), characterized in that it is provided with a mechanism for transmitting and receiving with three dedicated cables respectively.

(7) The central control unit is provided with a mechanism capable of separately controlling the plurality of power amplifiers by a digital control signal sent from the central control unit, in a plurality of groups or in a batch. (1) ~
The audio signal transmission device according to any one of (6). (8) According to the digital control signal sent from the central control unit, the central control unit outputs the sound wave output from the speaker of each audio unit with the digital audio signal delay time value corresponding to the propagation time to reach the listener. The audio signal transmission device according to any one of items (1) to (7), comprising a mechanism capable of controlling the power amplifier individually and for each of stereo or multi-channel.

(9) The central control device receives and verifies the status signal sent from each power amplifier via the cable connected to the bridge, and monitors the operating states of all the audio units, and at the same time, controls all the audio units individually. The audio signal transmission device according to any one of (2) or (4) to (8), characterized in that the audio signal transmission device is provided with a mechanism capable of collectively controlling a plurality of groups or all of them. (10) The central control unit controls the volume, delay time, phase, mute, limit level, input filter selection, etc. of the power amplifier individually and in stereo or multi-channel by the digital control signal sent from the central control unit. The audio signal transmission device according to any one of items (1) to (9), which is provided with a mechanism that can control each channel. (11) The power amplifier is provided with a mechanism capable of memorizing settings such as levels of control items by the digital control signal according to item (10) in a plurality of patterns (1) to (10). The audio signal transmission device according to claim 1.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a plurality of audio units each including a speaker box containing a speaker and power amplifiers arranged in the vicinity of the speaker box, and a digital amplifier for controlling the power amplifiers of the plurality of audio units are provided. A central control device for transmitting and receiving an audio signal and a digital control signal, a status signal transmitted from the power amplifier, and a signal for transmitting and receiving the signal transmitted and received by the central control device to the power amplifiers of the plurality of audio units. It is equipped with one or more cables bridge-connected between a plurality of power amplifiers, and the control of the plurality of audio units can be individually controlled in a plurality of groups or all at once, and at the same time sent from each power amplifier. The status signal can be monitored and controlled by the central control unit.

[0011]

[Embodiment] The configuration and operation of an embodiment of a conventional audio signal transmission device and an audio signal transmission device of the present invention will be described below with reference to the drawings. 1 is a connection diagram of the first embodiment of the audio signal transmission device of the present invention, FIG. 2 is a detailed connection diagram of the first embodiment of the audio signal transmission device, and FIG. 3 is a connection diagram of the second embodiment of the audio signal transmission device. FIG. 4 is a detailed connection diagram of the second embodiment of the audio signal transmission device, FIG. 5 is a connection diagram of the third embodiment of the audio signal transmission device, and FIG. 6 is a detailed connection diagram of the third embodiment of the audio signal transmission device. FIG. 7 is a connection diagram of a conventional audio signal transmission device. In the figure, 1 is a central controller, 2 is a signal source, 3 is a digital audio mixer, 4 is a controller, 5 is a digital control signal, 6 is a connection cable, 7 is an audio unit, 8 is a power amplifier, 9 is a speaker, 10 is a terminating resistor, 11 is a buffer, 12 is a decoder / encoder, 13 is an amplifier, 14 is an encoder output signal, 15 is a buffer, 16 is a connecting cable, 17 is a buffer,
18 is a connection cable, 19 is an audio mixer, 20
Is a power amplifier, and 21 is a speaker cable.

(Conventional example) In FIG. 7, a central control unit 1
The output signal of the audio mixer 19 to which the signal source 2 such as the CD reproducing device and the microphone is connected is distributed to the inputs of the plurality of power amplifiers 20 also arranged in the central controller 1, and the power amplifier output signal is A speaker cable 21 is connected to a plurality of speakers 9 installed inside and outside the building, respectively. As described above, conventionally, since the power amplifier 20 and the speaker 9 are separately arranged, the speaker cable 21 needs to be a thick cable capable of flowing a large current. I had to. Further, in consideration of the loss of the speaker cable 21, a space for disposing the power amplifier 20 having a large output as the equipment of the central control unit 1 and a powerful air conditioning equipment are required. Furthermore, there is a drawback in that it is susceptible to external noise and the like due to analog transmission.

(Embodiment 1 of the present invention) In FIGS. 1 and 2, a digital audio mixer 3 having a signal source 2 such as a CD reproducing device of a central control unit 1 and a microphone input.
Is controlled by a controller 4 having a CPU,
The input output signal of the signal source 2 such as a CD reproducing device and a microphone is converted into a digital audio signal in accordance with EIAJCP-1201, which is a stereo 2-channel format, for example. The output signal of the digital audio mixer 3 has a digital control signal 5 coded in the user data area of the digital audio signal, and is first transmitted via a connection cable 6 such as a pair of twisted pair cables in accordance with electrical specifications such as RS-485. Is input to the power amplifier 8 of the audio unit 7.
Furthermore, each power amplifier 8 is bridge-connected with a pair of connection cables 6 such as a twisted pair cable, and the output end of the final connection power amplifier 8 is the controller 4 of the central controller 1.
Connected to.

The digital audio signal input through the connection cable 6 is restored to an analog signal through the buffer 11 and the decoder / encoder 12, and the amplifier 1
3, the sound output is reproduced by the speaker 9. The digital control signal 5 restored in the same manner as described above controls the operation of the power amplifier 8 such as volume, delay time, phase, mute, limit level, and input filter selection for each channel. Further, the digital control signal 5 can individually control the power amplifiers 8 of the plurality of audio units 7 arranged in the building and outdoors, or can perform a plurality of group division controls or a total number of batch control. On the other hand, the status signal indicating the operating state of the audio unit 7 includes the internal temperature of the power amplifier 8, the operating state of the output relay, the operating state of each part of the power amplifier, the volume of the power amplifier, the delay time,
Check the contents set by the controller 4, such as phase, mute, limit level, input filter selection,
The digital control signal 5 and the status signal are coded again in the user data area of the digital audio signal by the decoder / encoder 12, and the buffer 15 is provided as the encoder output signal 14 together with the digital audio signal in accordance with the electrical specifications such as RS-485.
Through the connection cable 6 to the power amplifier 8 in the next stage, and the output end of the final connection power amplifier 8 is sent to the controller 4 of the central controller 1.

(Embodiment 2 of the present invention) In FIGS. 3 and 4, only the digital audio signal output of the digital audio mixer 3 of the central control unit 1 is, for example, RS-48.
The audio unit 7 is connected via a pair of twisted pair cables or other connection cables 6 in accordance with electrical specifications such as 5.
Is output to the power amplifier 8. On the other hand, the controller 4 having a CPU controls the digital audio mixer 3 and at the same time sends a digital control signal for controlling the operation of the power amplifier 8 to a pair of twisted pair cables or the like according to the electrical specifications of the RS-485 or the like. It is output to the power amplifier 8 via the connection cable 16. The status signal indicating the operating state of the audio unit is sent to the controller 4 of the central control unit 1 through the connection cable 16 via the buffer 15 as the encoder output signal 14 along with the digital control signal in accordance with the electrical specifications such as RS-485. Sent out. Connection cable 6
And 16 respectively bridge the input and output of the other power amplifier 8 one after another, and are terminated by the termination resistors 10 connected to the output terminal of the final connection power amplifier 8. Other operations are the same as those of the first embodiment of the present invention.

(Embodiment 3 of the present invention) In FIG. 5 and FIG. 6, the digital audio signal output of the digital audio mixer 3 of the central control unit 1 is the same as that of Embodiment 2, and a connecting cable 6 such as a pair of twisted pair cables is used. Is input to the power amplifier 8 via. On the other hand, the controller 4 having a CPU controls the digital audio mixer 3 and at the same time sends a digital control signal for controlling the operation of the power amplifier 8 to a pair of twisted pair cables or the like according to the electrical specifications of the RS-485 or the like. It is output to the power amplifier 8 via the connection cable 16. The status signal that indicates the operating status of the audio unit is
The encoder output signal 14 is sent to the controller 4 of the central control unit 1 via the buffer 15 via the connection cable 18 provided exclusively according to the electrical specifications of the RS-485 or the like. Connection cables 6, 16,
18 are bridge-connected to the other power amplifiers 8 one after another, and terminated by the terminating resistors 10 connected to the output terminal of the final connection power amplifier 8. Other operations are the same as those of the first embodiment of the present invention.

[0017]

According to the present invention, the following effects are exhibited. 1. According to the inventions of claims 1 to 6 of the present application, since the signal transmitted by the central control device is a digital signal of a digital audio signal and a digital control signal, the central control device for large-scale in-building or outdoor broadcasting, etc. With one or more connection cables for connecting the power amplifier, for example, a bridge connection of a thin twisted pair cable, and wiring work with only the power cable for the audio unit,
Cable costs and wiring work costs can be significantly reduced. In addition, since the power amplifiers with relatively large power consumption are distributed and arranged in the building or outdoors, the installation space in the central control unit can be minimized and the air conditioning equipment can be saved. Furthermore, since it is a digital signal, it is not easily affected by noise and the like, and since the loss of the speaker cable can be ignored, it is possible to provide acoustic broadcasting with sound quality excellent in fidelity. Furthermore, since the status signal sent from the power amplifier is also a digital signal, the same effect as described above can be provided.

2. According to the invention of claim 7 of the present application, the power amplifiers can be individually and collectively controlled in a plurality of groups or all by a digital control signal, and the speech or music can be controlled in consideration of the reverberation characteristics in the building or in the field. Since various characteristics of each power amplifier can be controlled according to a performance or the like, an optimum acoustic effect can be obtained. 3. According to the invention of claim 8 of the present application, for example, sound waves output from a large number of speakers arranged on the ceiling of a hall or the like reach a listener at the same time, so that the sound with excellent clarity and directivity is clear. A field can be formed. Also, it is necessary to connect a delay element to each speaker and each audio channel because it is easy to set the delay amount of the digital audio signal with the power amplifier for each individual and stereo or multi-channel by the digital control signal. There is no. 4. According to the invention of claim 9 of the present application, the operating states of all the audio units can be monitored by the status signal sent from the power amplifier via the cable connected to the bridge, and by grasping the operating states, each audio unit can be instantaneously detected. It is possible to control the unit, and it is possible to quickly respond to a failure. 5. According to the tenth and eleventh aspects of the present invention, the volume, delay time, phase, mute, limit level, input filter selection, etc. of each power amplifier are controlled so as to obtain the optimum acoustic effect in the building or outdoors. In addition, since a plurality of patterns of digital control items can be stored in memory, it is possible to instantly switch to a speech or music performance.

[Brief description of drawings]

FIG. 1 is a connection diagram of a first embodiment of an audio signal transmission device of the present invention.

FIG. 2 is a detailed connection diagram of the first embodiment of the audio signal transmission device.

FIG. 3 is a connection diagram of a second embodiment of the audio signal transmission device.

FIG. 4 is a detailed connection diagram of the second embodiment of the audio signal transmission device.

FIG. 5 is a connection diagram of a third embodiment of the audio signal transmission device.

FIG. 6 is a detailed connection diagram of the third embodiment of the audio signal transmission device.

FIG. 7 is a connection diagram of a conventional audio signal transmission device.

[Explanation of symbols]

1: Central control device 2: Signal source 3: Digital audio mixer 4: Controller 5: Digital control signal 6: Connection cable 7: Audio unit 8: Power amplifier 9: Speaker 10: Termination resistor 11: Buffer 12: Decoder / encoder 13: Amplifier 14: Encoder output signal 15: Buffer 16: Connection cable 17: Buffer 18: Connection cable 19: Audio mixer 20: Power amplifier 21: Speaker cable

Claims (8)

[Claims] 1. A plurality of audio units each comprising a speaker box having a built-in speaker and a power amplifier having a decoder / encoder arranged in the vicinity of the speaker box, in an audio broadcasting device in a large-area building or outdoors. A digital audio mixer for transmitting a digital audio signal to be output to a power amplifier of the plurality of audio units, and a controller for transmitting a digital control signal to control the audio mixer and transmitting / receiving a status signal transmitted from the power amplifier. A central control unit provided with the digital audio signal sent from the digital audio mixer; the digital control signal sent from the controller; and a status signal sent from the power amplifier. A plurality of connection cables for transmitting and receiving the digital audio signal, the digital control signal, and the status signal, which are bridge-connected between the plurality of power amplifiers for transmitting and receiving between the power amplifiers of the Dio unit. Characteristic audio signal transmission device. 2. The central control unit and the power amplifier send a composite signal of a digital control signal sent by the central control unit and a status signal sent by the power amplifier, and a digital audio signal by two dedicated cables respectively. 2. A mechanism for transmitting and receiving data is provided.
The audio signal transmission device according to. 3. A mechanism for transmitting and receiving a digital audio signal, a digital control signal, and a status signal transmitted by the power amplifier, which are transmitted from the central controller by the central control unit and the power amplifier, by using three dedicated cables, respectively. The audio signal transmission device according to claim 1, further comprising: 4. The central control device is provided with a mechanism capable of separately controlling the plurality of power amplifiers by a digital control signal sent from the central control device, in a plurality of groups, or in a batch. Claims 1 to 3 characterized
The audio signal transmission device according to claim 1. 5. A digital audio signal delay time value corresponding to a propagation time for a sound wave output from a speaker of each audio unit to reach a listener according to a digital control signal sent from the central control device by the central control device. 5. The audio signal transmission device according to claim 1, further comprising a mechanism for controlling each power amplifier individually and for each stereo or multi-channel. 6. The central control unit receives and verifies status signals sent from each power amplifier via a cable connected to a bridge, and monitors the operating states of all the audio units, and at the same time, controls all the audio units individually. The audio signal transmission device according to claim 1, further comprising a mechanism capable of collectively controlling a plurality of groups or all of them. 7. The volume of the power amplifier, the delay time, the phase, the mute, the limit level, the digital control signal sent from the central controller,
7. The audio signal transmission device according to claim 1, further comprising a mechanism capable of controlling input filter selection and the like individually and for each stereo or multi-channel. 8. The power amplifier is provided with a mechanism capable of memorizing a setting of a level of a control item by the digital control signal according to claim 7 in a plurality of patterns. The audio signal transmission device according to item 1.