Application Guide - Crown CM-30 Application Manual

CROWN MICROPHONE

APPLICATION GUIDE

FOR TELECONFERENCING
AND DISTANCE LEARNING
Thanks to teleconferencing, we can hold meetings
with people in another location without having to
travel there. Distance learning lets a professor teach
thousands of students in various locations, all at the
same time, in a cost-effective manner. It's also used
for corporate training.
Both teleconferencing and distance learning can save
you or your company thousands of dollars in travel
fees, not to mention the cost of hotels, meals, etc.
T e l e c o n f e r e n c i n g S y s t e m
Here is an overview of a typical teleconferencing
system (Fig. 1). Two meetings are set up around
conference tables. One meeting is in your company,
and the other meeting is in another company.
Figure 1. Teleconferencing system.
People at your meeting are picked up by micro-
phones. The sound of their voices is sent over stan-
dard telephone lines, or a satellite link, to the other
meeting location. There, the people can hear you
through a loudspeaker.
Similarly, mics at their location pick them up. Their
voices are sent over phone lines or satellite to your
location. You hear them through a loudspeaker. You
can talk back and forth, almost as if they were with
you at the conference table.
There might be cameras and video monitors set up so
that you can see the other people, and they can see
you.
A teleconferencing system is made of the following
components:
• Microphones
These pick up the voice of each participant. Mics can
be on the conference table or on a lectern. The mics
might be switchable: each user can turn his or her
mic on and off.
• Mixer
This electronic device combines all the mic signals
into one audio signal.
• Telephone coupler or codec
Short for coder-decoder, a codec takes the audio sig-
nal from the mixer, and sends it over the telephone
lines. On the sending end, it digitally codes the audio
into a telephone signal. On the receiving end, it
decodes the telephone signal back into audio.
Some codecs also send and receive video. Video sig-
nals must be sent via satellite, which relays the signal
to the distant location.
Some systems combine a mixer and codec into one
unit. Other systems combine mics, mixer and codec
into one unit.
• Telephone lines
Supplied by the telephone company, standard phone
lines (or high-speed phone lines) carry your audio
signal to the distant meeting location. There, a codec
converts the phone signal back into audio, which is
fed to a speaker. The meeting participants can hear
you through this speaker.
• Loudspeaker
In your meeting room, a loudspeaker plays the voices
of the people from the distant meeting.
• Video cameras and TV monitors
This is an option. Cameras and monitors let you see
the people at the distant meeting, and let them see
you. In many systems, the cameras automatically
switch to show the person speaking.