JP2000236597A - Sound signal transmitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily transmit sound with less speaker cable loss and with low installation cost by transmitting a digital audio signal and a digital control signal, which control plural audio units formed of power amplifiers that are arranged close to a speaker box, and transmitting transmission signals to the plural audio units. SOLUTION: A digital audio signal inputted through a connection cable 6 is restored into an analog signal through a buffer and a decoder/encoder and acoustic output is reproduced. A digital control signal 5 individually controls the power amplifiers 8 of plural audio units 7, controls the division of plural groups or collectively controls the whole amplifiers. A status signal showing the operation states of the audio units 7 checks a content which is previously set, is encoded again with the digital signal 5 by a decoder/encoder to the user data area of the digital audio signal and is transmitted to a controller 4.

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 central control device for transmitting digital audio signals and digital control signals. A plurality of audio units comprising power amplifiers arranged in one or more, with one or more cables bridge-connected between the plurality of power amplifiers,
The present invention relates to an audio signal transmission device that controls a plurality of audio units individually, a plurality of groups, or all of them collectively.

[0002]

2. Description of the Related Art In an audio broadcasting device in a large-area building or outdoors, a central control device and a plurality of power amplifiers are arranged in a control room, and a plurality of speaker boxes with built-in speakers are installed in different places. The power amplifiers and speakers are individually connected with speaker cables. Therefore, it is necessary to lay out a large-output power amplifier in consideration of the loss of the speaker cable and thick speaker cables capable of flowing a large current for the number of installed speakers. In addition, the analog transmission is susceptible to noise and the like, and the equipment is enormously expensive, resulting in poor sound quality.

[0003]

In view of the above situation, a speaker box with a built-in speaker and a plurality of audio units each including a power amplifier disposed in close proximity to the speaker box are installed at various places, and the center of the separate place is installed. A digital audio signal and a digital control signal are transmitted from the control device by one or a plurality of cables, and the power amplifiers are bridge-connected to provide an audio signal transmission device with low speaker cable loss, low installation cost and high sound quality. provide.

[0004]

Means for Solving the Problems As a result of intensive studies 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 having a built-in speaker and a power amplifier disposed in close proximity thereto, and the plurality of audio units A central controller for transmitting a digital audio signal and a digital control signal for controlling a power amplifier, and a bridge between the plurality of power amplifiers for transmitting a signal transmitted from the central controller to a power amplifier of the plurality of audio units An audio signal transmission device comprising one or a plurality of connected cables.

(2) In an audio broadcasting apparatus in a large-area building or outdoors, a plurality of audio units each including a speaker box having a built-in speaker and a power amplifier disposed in close proximity thereto, and the plurality of audio units are provided. Sending a digital audio signal and a digital control signal for controlling a power amplifier of the unit, transmitting and receiving a status signal transmitted from the power amplifier, a central control device, and transmitting and receiving signals transmitted and received by the central control device to the plurality of audio units. An audio signal transmission device comprising one or more cables connected in a bridge between the plurality of power amplifiers for transmission to the power amplifier.

(3) The central controller has a mechanism for coding a digital control signal transmitted by the central controller in a user data area of a digital audio signal and transmitting the digital control signal through a single cable. The audio signal transmission apparatus according to (1). (4) The central control device and the power amplifier code a digital control signal transmitted by the central control device and a status signal transmitted by the power amplifier in a user data area of a digital audio signal, and transmit and receive the digital audio signal through one cable. The audio signal transmission device according to (2), further comprising a mechanism.

(5) The central control unit and the power amplifier transmit a composite signal of a digital control signal transmitted by the central control unit and a status signal transmitted by the power amplifier, and a digital audio signal to two dedicated cables. Characterized by comprising a mechanism for transmitting and receiving by (2)
The audio signal transmission device according to the item. (6) The central control device and the power amplifier transmit a digital audio signal and a digital control signal transmitted by the central control device and a status signal transmitted by the power amplifier,
The audio signal transmission device according to (2), further comprising a mechanism for transmitting and receiving the data using three dedicated cables.

(7) The central control device has a mechanism capable of separately controlling a plurality of power amplifiers individually, in a plurality of groups, or collectively by using a digital control signal transmitted from the central control device. (1)-
(6) The audio signal transmission device according to any one of the items (6). (8) The digital control signal transmitted from the central control device causes the central control device to transmit a sound wave output from the speaker of each audio unit with a digital audio signal delay time value corresponding to a propagation time reaching the listener. The audio signal transmission device according to any one of (1) to (7), further including a mechanism capable of controlling the power amplifier individually and for each of stereo or multi-channel.

(9) The central control unit receives and verifies the status signals transmitted from the power amplifiers via the bridge-connected cables, monitors the operation states of all the audio units, and simultaneously controls all the audio units. The audio signal transmission apparatus according to any one of (2) or (4) to (8), further comprising a mechanism capable of collectively controlling a plurality of groups or all the groups. (10) The central controller controls the volume of the power amplifier, delay time, phase, mute, limit level, input filter selection, etc. individually and in stereo or multi-channel according to the digital control signal sent from the central controller. The audio signal transmission device according to any one of (1) to (9), further including a mechanism capable of controlling each channel. (11) The power amplifier is provided with a mechanism capable of storing the setting of the control item level or the like by the digital control signal according to the item (10) in a plurality of patterns. The audio signal transmission device according to any one of the above.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, there are provided a plurality of audio units each including a speaker box having a built-in speaker and a power amplifier disposed close to the speaker box, and a digital controller for controlling power amplifiers of the plurality of audio units. A central control device for transmitting and receiving an audio signal and a digital control signal, and a status signal transmitted and received from the power amplifier; and a central control device for transmitting and receiving signals transmitted and received by the central control device to power amplifiers of the plurality of audio units. A single or a plurality of cables connected in a bridge between a plurality of power amplifiers are provided, and the control of the plurality of audio units can be individually controlled, divided into a plurality of groups or all of them at once, and simultaneously transmitted from each power amplifier. The status signal can be monitored and controlled by the central control unit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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. FIG. 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. 4, FIG. 4 is a detailed connection diagram of Embodiment 2 of the audio signal transmission device, FIG. 5 is a connection diagram of Embodiment 3 of the audio signal transmission device, and FIG. 6 is a detailed connection diagram of Embodiment 3 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 control device, 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 connection 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) Referring to FIG.
The output signal of the audio mixer 19 to which the signal source 2 such as a CD playback device and a microphone is connected is distributed to the inputs of a plurality of power amplifiers 20 also provided in the central control device 1, and the power amplifier output signal is Speaker cables 21 are connected to a plurality of speakers 9 installed in the building and outdoors, respectively. As described above, conventionally, since the power amplifier 20 and the speaker 9 are disposed separately,
The speaker cable 21 needs a thick cable capable of flowing a large current, and has to be laid over the number of speakers 9 and over a long distance. Also, in consideration of the loss of the speaker cable 21, a high-power power amplifier 2
Further, a space for arranging No. 0 as the equipment of the central control device 1 and a powerful air conditioning equipment were required. Further, there is a disadvantage that the signal is easily affected by 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 and a microphone input of a central control device 1 is shown.
Is controlled by a controller 4 having a CPU,
The input output signal of the signal source 2 such as a CD player or a microphone is converted into a digital audio signal in accordance with, for example, a stereo 2-channel format EIAJCP-1201. An output signal of the digital audio mixer 3 has a digital control signal 5 coded in a 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.
Further, each power amplifier 8 is bridge-connected with a pair of twisted pair cables or the like connection cable 6, and the output terminal of the final connection power amplifier 8 is connected to the controller 4 of the central control device 1.
Connected to.

The digital audio signal input through the connection cable 6 is restored to an analog signal via a buffer 11 and a decoder / encoder 12, and is restored to an analog signal.
3. A sound output is reproduced by the speaker 9. The digital control signal 5 restored in the same manner as described above controls the volume, delay time, phase, mute, limit level, input filter selection, and other operations of the power amplifier 8 for each channel. In addition, the digital control signal 5 can individually control the power amplifiers 8 of the plurality of audio units 7 disposed inside and outside the building, and can control a plurality of groups or a batch control of all the units. On the other hand, the status signal indicating the operation state of the audio unit 7 includes the internal temperature of the power amplifier 8, the operation state of the output relay, the operation 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, etc.
The digital control signal 5 and the status signal are coded again by the decoder / encoder 12 into the user data area of the digital audio signal, and the encoder 15 outputs a buffer 15 together with the digital audio signal as an encoder output signal 14 in accordance with the electrical specifications such as RS-485.
Via the connection cable 6 to the power amplifier 8 of the next stage, and the output terminal of the final connection power amplifier 8 is transmitted to the controller 4 of the central control device 1.

(Embodiment 2 of the present invention) In FIG. 3 and FIG. 4, only the digital audio signal output of the digital audio mixer 3 of the central control unit 1 is, for example, RS-48.
Audio unit 7 via a connection cable 6 such as a pair of twisted pair cables in accordance with electrical specifications such as 5
Is output to the power amplifier 8. On the other hand, the controller 4 including the CPU simultaneously controls the digital audio mixer 3 and simultaneously transmits 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. The signal is output to the power amplifier 8 via the connection cable 16. The status signal indicating the operation state of the audio unit is transmitted to the controller 4 of the central control device 1 through the connection cable 16 via the buffer 15 as an encoder output signal 14 in accordance with the electrical specifications such as the RS-485 together with the digital control signal. Sent out. Connection cable 6
, 16 are connected one after the other to the input and output of the other power amplifier 8, and terminated by a terminating resistor 10 connected to the output terminal of the finally connected 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 FIGS. 5 and 6, the digital audio signal output of the digital audio mixer 3 of the central control unit 1 is connected to a connection cable 6 such as a pair of twisted pair cables in the same manner as in the second embodiment. Is input to the power amplifier 8 via the. On the other hand, the controller 4 including the CPU simultaneously controls the digital audio mixer 3 and simultaneously transmits 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. The signal is output to the power amplifier 8 via the connection cable 16. The status signal indicating the operation state of the audio unit is
In accordance with the electrical specifications of the RS-485 or the like, the signal is transmitted as an encoder output signal 14 to the controller 4 of the central control device 1 via a buffer 15 through a connection cable 18 provided exclusively. Connection cables 6, 16,
The bridges 18 are sequentially bridge-connected to the other power amplifiers 8 and terminated respectively by the terminating resistors 10 connected to the output terminal of the finally connected 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 invention 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 a large-scale building or outdoor broadcasting or the like. And one or more connection cables to connect the power amplifier, for example, bridge connection of a thin twisted pair cable, and can be performed by wiring work only for the power cable for the audio unit,
Cable costs and wiring work costs can be greatly reduced. In addition, since power amplifiers having relatively large power consumption are distributed in a building or outdoors, the installation space in the central control device can be minimized, and the air conditioning equipment can be reduced. Furthermore, since it is a digital signal, it is hardly affected by noise and the like, and furthermore, since the loss of the speaker cable can be neglected, it is possible to provide an audio broadcast with excellent fidelity and sound quality. 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 amplifier can be divided and controlled individually, in a plurality of groups or in a batch by the digital control signal, and speech or music can be controlled in consideration of the reverberation characteristics in the building or the outdoors. Since various characteristics of each power amplifier can be controlled in accordance with a performance or the like, an optimal sound 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 disposed on the ceiling of a hall or the like reach the listener at the same time, so that sound with excellent clarity and clear directionality is obtained. A field can be formed. In addition, since the delay amount of the digital audio signal can be easily set by the power amplifier for each of the individual and stereo or multi-channels by the digital control signal, it is necessary to connect a delay element for each speaker and each audio channel. There is no. 4. According to the ninth aspect of the present invention, the operation state of all audio units can be monitored by the status signal transmitted from the power amplifier via the bridge-connected cable, and the operation state can be grasped, so that each audio unit can be instantaneously monitored. The unit can be controlled, and quick response to a failure can be taken. 4. According to the tenth and eleventh aspects of the present invention, the volume, delay time, phase, mute, limit level, input filter selection, and the like of each power amplifier are controlled so as to obtain an optimal sound effect in a building or outdoors. Since a plurality of digital control items can be stored in the memory, switching can be instantaneously performed in response to speech or music performance.

[Brief description of the drawings]

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

FIG. 2 is a detailed connection diagram of Embodiment 1 of the audio signal transmission device.

FIG. 3 is a connection diagram of Embodiment 2 of the audio signal transmission device.

FIG. 4 is a detailed connection diagram of Embodiment 2 of the audio signal transmission device.

FIG. 5 is a connection diagram of Embodiment 3 of the audio signal transmission device.

FIG. 6 is a detailed connection diagram of Embodiment 3 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 unit 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: Terminating 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 (11)

[Claims] 1. An audio broadcasting apparatus in a large-area building or outdoors, comprising: a plurality of audio units each including a speaker box having a built-in speaker and a power amplifier disposed in close proximity thereto; A central control unit for transmitting a digital audio signal and a digital control signal for controlling a power amplifier of the unit, and the plurality of power amplifiers for transmitting a signal transmitted from the central control unit to the power amplifiers of the plurality of audio units; An audio signal transmission device comprising one or a plurality of cables connected in a bridge. 2. An audio broadcasting apparatus in a large-area building or outdoors, comprising: a plurality of audio units each including a speaker box having a built-in speaker and a power amplifier disposed in close proximity to the speaker box; Transmitting a digital audio signal and a digital control signal for controlling the power amplifier, transmitting and receiving a status signal transmitted from the power amplifier, and transmitting and receiving signals transmitted and received by the central control device to the plurality of audio units. An audio signal transmission device comprising one or more cables connected in a bridge between the plurality of power amplifiers for transmission to an amplifier. 3. The system according to claim 1, wherein the central control unit has a mechanism for coding a digital control signal transmitted by the central control unit in a user data area of a digital audio signal and transmitting the digital control signal through a single cable. The audio signal transmission device according to claim 1. 4. The central control unit and the power amplifier code a digital control signal transmitted by the central control unit and a status signal transmitted by the power amplifier in a user data area of a digital audio signal, and use a single cable. 3. The audio signal transmission device according to claim 2, further comprising a transmission / reception mechanism. 5. The central control unit and the power amplifier transmit a digital signal and a composite signal of a status signal transmitted by the central control unit and a digital audio signal, respectively, using two dedicated cables. 3. A transmission / reception mechanism is provided.
An audio signal transmission device according to claim 1. 6. A mechanism in which the central control device and the power amplifier transmit and receive digital audio signals, digital control signals transmitted by the central control device, and status signals transmitted by the power amplifier, respectively, with three dedicated cables. 3. The audio signal transmission device according to claim 2, further comprising: 7. A central control device having a mechanism capable of separately controlling a plurality of power amplifiers individually, in a plurality of groups, or collectively by using a digital control signal transmitted from the central control device. Claims 1 to 6
The audio signal transmission device according to any one of the above. 8. 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 transmitted from the central control device. The audio signal transmission device according to any one of claims 1 to 7, further comprising a mechanism capable of controlling each power amplifier individually and for each of stereo or multi-channel. 9. The central controller receives and checks status signals transmitted from each power amplifier via a bridge-connected cable, monitors the operation state of all audio units, and simultaneously controls all audio units individually. The audio signal transmission device according to claim 2, further comprising a mechanism capable of collectively controlling a plurality of groups or all of the plurality of groups. 10. The central control unit controls the volume, delay time, phase, mute, limit level, input filter selection, etc. of a power amplifier individually and in stereo or multi-channel according to a digital control signal transmitted from the central control unit. The audio signal transmission device according to any one of claims 1 to 9, further comprising a mechanism capable of controlling each of the channels. 11. The power amplifier according to claim 1, wherein the power amplifier includes a mechanism capable of storing a setting of a level of a control item or the like by a digital control signal according to claim 10 in a plurality of patterns. 2. The audio signal transmission device according to claim 1.