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Okay, let's apply that
"heart" idea to a simplified drawing of an audio system for
radio. See
a graphic here.
- The "Audio Console" is the
heart.
- On the back of the console are three
"inputs," one from a microphone, one from a CD player, and
one from an audio recorder. Notice that the signal can only go
one way from a microphone and from a CD player, neither being able
to record. But the "audio recorder," which could be
a tape machine or hard disk drive, is able to play (thus creating
input to the console) or record (thereby receiving output from the
console). See #4, below.
- The audio console is able to regulate
-- with special on/off switches -- which of the three inputs is
allowed to pass through to the output. And, the console is
able to regulate the signal strength of each of those inputs, using
special volume controls.
- This console shows only two outputs.
They're basically the same, but directed to different applications.
The first is "program out," and it represents the master
output of the console. Its signal goes first to some
"signal processing equipment" such as a
limiter/compressor, and then to the transmitter.
- The second output is split between
headphones for the operator (needed especially when a microphone is
turned on) and a loudspeaker. Both are used to monitor the
program being created.
- Of course, an audio recorder could be
put in the line after the signal processing equipment to record the
master output, after all enhancements. In
fact, this diagram shows by dotted line a signal path from the final
signal processing device to the input section of the audio recorder.
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Now let's move
to a more complete picture of the "On-air audio/radio system."
See
a graphic of it here.
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At the
center is the mixer -- or board, which physically is installed in
the audio booth. Across the top of the mixer are shown the
"input signals." These come from lots of different
sources, such as microphones, CD players, networks, and so on.
A basic radio system will be set up to handle about a dozen inputs,
with 25-30 inputs being more common.
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The mixer
then controls which of the inputs is mixed to output. It also
controls the volume level -- or loudness -- of each. And, it
can do some other things, such as control the overall or master
level of output.
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These mixed
signals then are sent to outputs, which are shown on the right side
of the mixer.
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Along the
bottom of the mixer are shown several special-purpose channels.
One is to trigger the on-air light on the studio door. Anytime
a microphone is mixed to output, the on-air light should
automatically be turned on. The second integrates the studio
clock to the mixer. Third is for studio monitors, which are
powerful loudspeakers driven by a power amplifier. And
fourth is an output jack in the board for plugging in the operator's
headsets.
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On the left
side of the mixer is shown a sophisticated power supply.
They're used because household power (a wall outlet) is too
unstable.
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Notice that
some inputs come from equipment that also are set to receive output
from the board. That's because a CD deck, for example, can be
used to record the commercial or program, or it can be used to play
back the commercial or program.
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And, notice
that each of the four microphones sends its signal first to a
"voice processor," which allows you to fine-tune the sound
of the microphone before sending it to the mixer.
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And now let's
ramp up to a video/television system. See
a graphic of it here.
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The
video/television system comprises several subsystems: audio (which
is like the audio/radio system above), video, headsets or intercom,
teleprompter, lighting and others.
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On the left
side of the graphic you'll see three microphones whose signals go to
inputs on the audio mixer. Below the microphones is a
"floor monitor speaker," which is an audio monitor for use
in the studio. That speaker takes an output from the mixer.
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Below the
mixer is an audio cassette deck, a DAT deck (digital audio tape),
and a reel-to-reel recorder. Beside them are a desktop
computer which operates Software Audio Workshop's audio/nonlinear
editing system.
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Shown at
the lower right corner of the mixer is the master output, which
sends signal first INTO the two videotape recorders, and then to the
master output for the whole system. Videotape machines also
have their audio outputs connected to the audio mixer as mixer
inputs, and their video outputs connected to the switcher as
switcher inputs.
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Shown at
the top of the audio mixer is a video program monitor, used by the
audio operator to see what's going on in the video channel.
Also shown are a pair of small audio speakers, which are the audio
monitors for use in the audio booth.
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Let's
return to the left side of the graphic where the microphones are.
Above them are a program monitor and a "floor director
headset." The program monitor is used in the studio so
everyone can see what's going on. Big studios (news) also hang
monitors on the front of the cameras so talent can see what's on-air
through peripheral vision. The headset, as shown, is a
wireless intercom, connected to a push-to-talk microphone in the
control room. Because the floor director has to move around
quickly in the studio, his/her headset is often wireless -- which
means the floor director wears a little transceiver on his/her belt.
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Now let's
skip up to the very top, left corner. You see a spotlight.
Assume that's one of a hundred or so which are hung in the studio.
As shown, the lighting instruments are wired to the Lighting Control
Board (light mixer). The Lighting Control Board allows
individual lights to be turned on or off, and to be faded up from
off, or faded down and out. In fact, the light instruments are
connected to a back-of-house "dimmer pack" which actually
turns up and down the electricity sent to lights; the Control Board
is simply a device that controls the dimmer pack. The Lighting
Director also has a program monitor and a special headset channel
(to listen to the director or to talk to lighting assistants
elsewhere in the studio).
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Now let's
continue with the video subsystem, starting with the cameras.
You'll see that the output of each is wired to an input on the video
production switcher. The video production switcher interface
panel is to the video production switcher as the lighting control
board is to the lighting dimmer pack. In our control room, the
switcher (interface panel) is mounted on a desktop console, while
the switcher itself is mounted in an under-console equipment rack.
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Shown above
the switcher are four more inputs. The character generator is
a special-purpose computer that creates text, usually used as
"supers." In this graphic, the brand name of the
character generator is "Inscriber." Next is
the still store or still file device, which stores on hard disk
individual frames of video which you can capture by a mouseclick.
Frames of captured video often are used as backgrounds for
production graphics. Next to the still store is the computer
graphics unit, in this case a "PaintBox" brand.
A computer graphics subsystem is simply a broadcast version of
Photoshop, Illustrator and Premier. Shown next to the computer
graphics editor is the Digital Video Effects box, or DVE. This
equipment allows creation of special transitions: slide, flip,
mosaic, snowflake, and others. In reality, these inputs
to the switcher are not connected as the graphic shows.
Cameras, for example, are wired to the Camera Control Units which
are mounted in a rack at the video engineer's position. The CG
and computer graphics units usually are located somewhere in the
control room, while the Still Store and DVE units are in a backroom
rack (they're operated remotely at the switcher).
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From the
lower right corner of the switcher are shown two outputs. One
is program, or the actual picture that will be transmitted live like
news or be recorded like commercials. The program output goes
to a program monitor, to a waveform monitor, and a vectorscope, and
to inputs on the two videotape recorders, before being sent to
the transmitter room. The other output is preview, the picture
that will be transmitted next, which is sent only to a
monitor.
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The
waveform monitor shows everyone how a signal looks in terms of
blackness and whiteness. The vectorscope shows how that signal
looks in terms of its three primary colors (red, green and blue).
The video engineer continuously refers to these monitors to make
sure the pictures all are consistent in white value, black value,
and color.
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Before
leaving the control room, let's go back and pick up the remainder of
the headset/intercom subsystem. Shown
behind the three cameras in the studio are three wireless headsets
for the camera operator. In the control room are
intercom stations for the director, the technical director (the
person who switches), and the producer. Beside the SAW in the
audio booth is a headset/intercom station for audio. An
intercom station is shown for the person running the videotape
machines and servers (often in a separate room because of
noisiness). And the final intercom station is shown for the
person who is operating the Master Control Room.
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To the
lower left of the switcher is shown a "Monitor Wall."
Actually, this wall of monitors is built in front of the production
people who sit in production control. The bottom row of
monitors show current video from Camera #1, Camera #2, and Camera
#3, as well as a space for an extra camera (such as one for a
weather remote). Above the camera monitors are Character
Generator, Still Store, a computer, and the DVE (again, these simply
show current video from these devices). Above those are
Videotape machines 1 through 4. Most stations also have video
servers replacing one or more videotape machines. And in the
top row are feeds from Edit Suite #1 and #2, and Satellite Feeds #1
and #2.
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Professional
studios never number/label their inputs as this graphic shows.
Notice that this control room has Cameras 1 and 2, Videotapes 1 and
to, Video servers 1 and 2, Edit suites 1 and 2, and Satellites 1 and
2. That's redundant and clumsy. More important, it's too
hard to speak, and too easy to confuse. Professional studios,
ours included, number cameras 1 through 4, then number tape machines
11 through 20, then number video servers 22 through 24, and so on.
Or, sources can be named, not numbered: Moe, Larry and
Curley.
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Now we can
move downstream from production control to the Master
Control Room. A "master" is used so that ongoing
programming can be transmitted while production people are busy in
the production control room making programs, commercials, promos,
and other materials to be recorded for later on-air use.
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Master can
choose from many inputs (which are outputs for production control
and audio!). He/she can air material from videotape machines,
from an automated videotape machine system, from servers, and/or
from network (which usually comes in via satellite). The output
of master control goes to the transmitter (known as
terrestrial), and/or to a satellite uplink, and/or to the local
cable companies' headends. Signals sent to satellites are
usually compressed first.
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Finally,
this Television System graphic, as drawn, shows a "field
production" subsystem. Look at the very bottom of the
graphic, left side. You'll see a TV camcorder (configured for
use in the field) and two microphones. The mikes go into a
little mixer which sets levels correctly, and then inputs the
combined audio signal to the camcorder. A videotape goes into
the camcorder, and "field audio and video" are recorded on
it.
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Next, the
tape is put into an editing room videotape machine. Hooked to
that machine is a computerized editing system. The various
shots and audio tracks are copied to the computer, rearranged
suitably, and then recorded out to another "Edited Master"
videotape. That Edited Master videotape can be taken to
one of the control room videotapes, or it can be taken to a master
control machine, for playback in a production or for playback on the
air.
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In these
days of "tapeless" recording, you'll find that many
videotape machines have been replaced by a "media server."
So, if the field production subsystem happens to be in the newsroom
or in the production department, then one camcorder can be replaced
in this graphic by a dozen or so physical camcorders. Each of
these would record on "P2 cards," not on videotape.
P2 cards currently hold from 4 to 64 gigabytes, with 64 gb
representing about 4 hours of recording time. After recording,
when the P2 cards are returned to the station, the raw video from
the field can be "ingested" directly from the P2 card to a
media server using a firewire connection. The editing system
can call up video and audio directly from the server for editing
purposes. The edited master then is simply rerecorded on the
media server. From the production or master control room, the
server can be cued, and the story can be played directly to air.
That means the data file which the camcorder originally creates is
allowed to move into the station, through editing and to an on-air
status without ever having been recorded to tape.
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As shown in
the graphic, there's an intercom/headset station in the news or
production editing room, used so that the production or master
control rooms can stay in touch with the video editor who is working
on a soon-to-air piece.
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