JP3214971B2 - Remote mixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to remotely control a mixing amplifier or the like placed on a controlled side by operating a remote fader or the like placed on a control side, and at the same time, to a controlled side if necessary. The present invention relates to a remote mixing device that also supplies power to the remote mixing device.

[0002]

2. Description of the Related Art Conventionally, in this type of remote mixing apparatus, an audio signal and an audio level control have been used to connect a control side on which a remote fader is installed and a controlled side on which a microphone and a mixing amplifier are installed. It was necessary to separately lay transmission lines for supplying signals and power, respectively.

[0003]

However, when mixing resources (microphones) remote from the control side, the number of cables corresponding to the resources must be drawn into a mixing room such as a relay truck. There was a complication.

In addition, the remote mixing apparatus itself requires a total of three cables for supplying power, in addition to the signal lines for the audio signal and the audio level control signal.

Accordingly, a first object of the present invention is to provide a conventional mixing technique that requires a large amount of laid cables.
It is an object of the present invention to provide a remote mixing device capable of managing an audio level with a parallel cable.

A second object of the present invention is to provide a remote mixing apparatus which can supply power via a single balanced cable while transmitting and receiving audio level control information and an audio signal. It is in.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a remote mixing apparatus for controlling the mixing of audio signals obtained from a plurality of microphones via a single balanced transmission line. First coupling means for converting the audio level control information of a plurality of channels specified by the side into serial digital data, and transmitting the data in phase on two lines of the balanced transmission line, and via the balanced transmission line Second coupling means for extracting the audio level control information from the signals received on the controlled side; and a sound signal mixed based on the audio level control information extracted by the second coupling means. A first transformer for inputting and transmitting out of phase on two lines of the balanced transmission line, and a signal received on the control side through the balanced transmission line,
A second transformer for canceling the signal component of the audio level control information and extracting the audio signal, wherein the transmission and reception of the audio level control information and the audio signal are performed through a single balanced transmission line It is.

[0008]

According to the above arrangement of the present invention, when remote controlling a mixing amplifier located in a remote place, an audio signal, an audio level control signal and an amplifier driving power supply voltage are multiplexed on a single balanced transmission line. In addition, it is possible to mix a large number of remote audio resources via a single balanced cable.

[0009]

Embodiments of the present invention will be described below in detail.

FIG. 1 is a block diagram showing a remote mixing apparatus according to one embodiment of the present invention.

In FIG. 1, the control side and the controlled side are connected via a balanced transmission line 5. Here, on the control side, a remote fader 1, an A / D converter 2, a parallel / serial converter 3, and a multiplexing / demultiplexing unit 4 (the control data 3S is multiplexed on a balanced transmission line to separate the audio signal 9S). Is included. The balanced transmission line 5 is composed of one balanced cable (a shielded two-wire cable). On the controlled side, the multiplexing / demultiplexing unit 6 (multiplexes the mixed audio signal 9S on the balanced transmission path and separates the control data 3S), the serial / parallel converter 7, the D / A converter 8, and the VCA of the mixer
(Voltage Control Amplifier) 9, a plurality of microphones MIC are included.

The above-mentioned transmission line (one balanced cable) 5
And multiplexing / demultiplexing units 4 and 6 connected to both ends thereof, as shown in FIG.
Buffer amplifier AMP and transformer with intermediate tap 6
0, a buffer amplifier AMP ′, and a waveform shaping section 62.

First, the overall operation in this embodiment will be described with reference to FIG.

On the control side, first, a DC voltage (audio level control information) corresponding to the position of the remote fader 1 of each channel is obtained and sent to the A / D converter 2. A /
The D converter 2 converts the analog voltage of each channel into digital data.

The digital data of each channel obtained from the A / D converter 2 is input to a parallel / serial converter 3 and converted into serial control data (audio level control information) 3S. Next, the serial control data (audio level control information) 3S obtained in this way is sent to the balanced transmission line (cable) 5 via the multiplexing / demultiplexing unit 4.

On the controlled side, the serial control data 3S is extracted via the multiplexing / demultiplexing unit 6, and the extracted data is input to the serial / parallel converter 7 at the next stage and converted into digital data for each channel. , This digital data is D /
The signal is converted into an analog voltage by the A converter 8. Then, the audio level of the VCA 9 of the mixer is controlled by an analog voltage.

Finally, the volume of each microphone MIC is controlled by the VCA 9 and extracted as a mixed audio signal 9S.

The mixed audio signal 9S obtained in this way is transmitted to the balanced transmission line (cable) 5 via the multiplexing / demultiplexing unit 6. The multiplexing / demultiplexing unit 4 on the control side
As a result, the audio signal 9S is separated and output.

Next, referring to FIG. 2, the multiplexing / demultiplexing process of the serial control data 3S and the audio signal 9S will be described.
This will be specifically described.

First, in order to transmit the serial control data 3S from the control side, the serial control data 3S is superimposed on the two lines 5A and 5B included in the balanced transmission line 5 in the same phase. Actually, in-phase data signals are supplied directly to the lines 5A and 5B via the buffer amplifier AMP and the balance resistors R1 and R2. That is, the serial data is transmitted to two lines of the balanced transmission line 5 without passing through the transformer 40 on the control side.

On the other hand, the mixing audio signal 9
In order to send out S, a line 5A, 5A,
The audio signal 9S is supplied to 5B. Therefore, the transformer 6
The audio signals generated on the lines 5A and 5B connected to the secondary winding side of 0 have opposite phases.

The transformer 40 provided on the control side has an intermediate ground tap similarly to the transformer 50 provided on the controlled side. Therefore, the audio signal transmitted on the lines 5A and 5B in the opposite phase is reproduced as the original audio signal 9S. But,
Since the serial control data 3S superimposed on the lines 5A and 5B have the same phase, the output of the transformer 40 does not affect the secondary-side output by the common-mode component removing operation.

Next, paying attention to the lines 5A and 5B on the controlled side, since the audio signals 9S are out of phase with each other, they are canceled at the input end of the buffer amplifier AMP 'to become zero input, and Only the control data 3S is applied. Then, the output of the buffer amplifier AMP 'is pulse-shaped in the waveform shaping section 62, and the serial control data 3S sent from the control side is reproduced.

The digital parallel data obtained from the faders of each channel is converted into serial data, and after the data header (FFH), the digital data is converted to serial data. No. 1 fader value (00H to FEH), No. 1 Fader value of 2, N
o. No. 3 fader value. 4 are sequentially transmitted on the transmission path.

On the receiving side, the data header (FF
H), the data of each subsequent fader is converted to D
A / A converter 8 converts the voltage into a voltage, and VCA 9 of each channel
Add to

As described above, the audio level is controlled by the VCA according to the information of the remote fader.

FIG. 3 shows another embodiment of the present invention.
In the illustrated embodiment, a DC power supply is directly connected to the line 5A of the balanced transmission line 5 to supply power to the controlled side. Also, for the serial control data 3S and the mixing audio signal 9S, the DC voltage is cut by inserting capacitors C at the entrance and exit of the control side and the controlled side so as not to affect the transmission signal.

The two embodiments described above offer the following specific advantages.

1) Since only one microphone cable is required for the control line and the main line, the work of cable setting is reduced.

2) Since the number of control devices and controlled devices can be one-to-many instead of one-to-one, the scale can be easily expanded.

3) Since data transmission is serial, by increasing the transmission speed or suppressing the resolution of the fader,
Control channels can be increased to a significant number.

4) There is a possibility of developing a more full-scale device such as equalizing and gain adjustment of a head amplifier as well as remote control of a fader.

5) The level can be easily balanced because the main mixer can perform the collective management even when nobody goes to the destination.

[0034]

As described above, according to the present invention, 1
Mixing control similar to that of the related art can be performed simply by pulling the cable, so that the cable laying operation is greatly reduced. In addition, the sound level of a wide range of resources can be centrally managed at one place.

That is, according to the present invention, in the past, the cable had to be drawn into the mixing room (such as a relay truck) by the number of resources (microphones) in the relay.

In order to remotely control the mixing amplifier, three audio signal lines, a control line, and a power supply line were required.

Such conventional inconveniences can be eliminated at once.

Further, according to the present invention, since the bidirectional transmission of the audio signal and the control signal can be performed without performing the modulation and demodulation in the base band, not only the simple circuit configuration can be realized, but also In addition, it is possible to prevent deterioration of the audio signal due to modulation and demodulation.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram detailing a main part of FIG.

FIG. 3 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 remote fader 2 A / D converter 3 parallel / serial converter 4 multiplexing / separating unit 5 transmission line (cable) 6 multiplexing / separating unit 7 serial / parallel converter 8 D / A converter 9 VCA (mixer)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-176214 (JP, A) JP-A-63-206033 (JP, A) JP-A-6-350490 (JP, A) 53336 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B 3/50 H04H 7/00

Claims (3)

(57) [Claims] 1. A remote mixing device for mixing and controlling audio signals obtained from a plurality of microphones via a single balanced transmission line, wherein audio level control information of a plurality of channels specified by a control side is serial digitally output. First coupling means for converting the data into data and transmitting the data on the two lines of the balanced transmission line in the same phase; and selecting the audio level from the signals received on the controlled side via the balanced transmission line. Second coupling means for extracting control information; inputting the audio signal mixed based on the audio level control information extracted by the second coupling means, and transmitting the signals in opposite phases on two lines of the balanced transmission path A first transformer that performs the control, and cancels out the signal component of the audio level control information from the signal received on the control side via the balanced transmission line to extract the audio signal. And a second transformer, remote mixing device, characterized in that for exchanging the audio level control information and the audio signal through a single balanced transmission path. 2. The remote mixing device according to claim 1, wherein a shielded two-wire cable is used as the balanced transmission line. 3. The apparatus according to claim 1, further comprising: a DC element capacitor for supplying power from a control side to a controlled side via one line of said balanced transmission line, wherein said audio level control information and A remote mixing apparatus characterized in that power is supplied via a single balanced transmission line in conjunction with transmission and reception of an audio signal.