Sound Choice SC-186Kx2 User manual

INSTRUCTION MANUAL
MODEL SC-186Kx2
INFRARED AUDIO TRANSMITTER
498 Long Hill Road
Gillette, NJ 07933 USA
908-647-2650
fax: [phone]
toll free: 877-896-5084
email: [email protected]
website: www.assistivelistening.net
© 1994-2007 US Patents 5,548,654 and 5,596,648
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INTRODUCTION:
The SC-186Kx2 is a portable, wireless, infrared assistive
listening transmitter. It is designed for use with amplified in-
frared headset receivers in a variety of situations. The
transmitter and headset combination can provide high qual-
ity assistive audio coverage for government, corporate or
institutional settings in small to medium-size rooms. Cover-
age from small conference rooms through audiences of
over one hundred seats can be achieved with a minimum of
setup time or complications. This system provides an ef-
fective and inexpensive way to provide a needed service
and to bring numerous locations into compliance with the
Americans With Disabilities Act (ADA).
The self-contained pressure zone microphone, sound
equalization circuits, automatic level control and advanced
technology high-power infrared light emitting diode (LED)
emitters provide a complete transmitter system in a paper-
back book-size finished wood box. Available accessories
include a 360° omnidirectional emitter-microphone box (SC-
MEB) and a remote control mute switch (SC-RMS). Industry
standard 880 nm secure optical transmissions are on paired
2.3 mHz and 2.8 mHz frequency modulated carrier infrared
frequencies and can be received by headsets available
from Sound Choice.
The special feature of the SC-186Kx2 is that while the two
channels transmit the same audio signal most of the time,
one channel transmitting at 2.3 mHz can be muted in order
to produce private sidebar or other conversations that can-
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not be heard by listeners wearing headsets. The other
channel transmitting on 2.8 mHz will always remain on so
that listeners entitled to hear private communications can
continue to do so unmuted.
A typical situation would be in court where it would not be
permissible for a juror to hear certain private discussions
during the proceedings. A judge or clerk could electively
mute the transmission of the assistive listening signal during
those exchanges. At the same time, a defendant would
have the right to hear the conversation even if not physi-
cally at the bench. The second channel would continue to
transmit even when the juror’s channel is muted.
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INSTRUCTIONS FOR BASIC SETUP:
1. Unpack the transmitter, power transformer, 360°
microphone-emitter box (SC-MEB if ordered), remote mute
control and cable (SC-RMS if ordered), 360° emitter disk
(SC-360 if ordered), and at least one headset receiver.
Please see the instructions packed with the headset con-
cerning its setup and use.
2. Plug the transformer's small barrel plug into the power
jack labeled “16 VAC” located next to the power switch on
the transmitter's rear panel. Plug the other end into any 120
volt AC outlet. A common AC extension cord may be used
if needed.
3. Turn the power switch to the "on" position. The yellow
"power on" indicator LED will light.
4. While wearing a headset with a charged battery and its
volume control set to a pleasing level, stand in front of the
transmitter and face the infrared emitter (the front panel
with the LED emitters). Room sounds picked up by the
transmitter's internal microphone should be heard clearly.
There is nothing else to set or adjust on the transmitter
since all volume level settings are automatic. The volume
control is on the receiver.
Infrared audio light will be projected forward from the
emitter the way a floodlight or headlight beam illumi-
nates an area in front of it, while leaving areas to the
sides and behind darker.
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SC-186K TOP VIEW
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SC-186Kx2 TOP VIEW
note: The BNC connector on the upper left of the top plate is
an option. Your system might not have this option included.
6

MICROPHONE-EMITTER BOX (SC-MEB):
5. Attach the end of the SC-MEB’s DIN plug to the DIN jack
on the back panel labeled “SLAVE”. A small red indicator
inside the box will be visible through one side of the red
translucent box.
6. The SC-MEB also has a microphone on the top surface.
This will act as a second audio pickup point when plugged
into the main unit. The two microphones will behave ex-
actly the same regarding muting and using external audio
connections (please see “Using Other Input Sources”)
In addition to the long forward throw of infrared light
from the main transmitter beam, the 360° emitters
projecting through all four side walls of the SC-MEB
will illuminate areas to the sides and back of the trans-
mitter like a table lamp.
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REMOTE MUTE CONTROL (SC-RMS):
7. Connect the small 3.5 mm stereo plug to the jack on the
remote control box.
8. Connect the mini DIN plug to the jack labeled "MUTE" on
the transmitter's rear panel.
9. When connected properly, a small indicator LED will light
on the control box's top surface whenever the transmitter
power is on.
10. To mute the audio signal from the transmitter in order to
insure privacy during side bar or other confidential conver-
sations, push the "MUTE" switch on the remote control box.
The LED indicator will begin to blink as a reminder that the
transmitter is muted. The LED will continue flashing until the
pushbutton switch is pressed again releasing the mute and
restoring the audio signal.
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OMNIDIRECTIONAL 360° EMITTER (SC-360):
11. Attach one end of the stalk’s RCA phono plug to the
emitter disk's matching RCA jack. The other RCA plug end
should be plugged into the RCA to BNC adaptor. (Only SC-
186Kx2 units ordered with this option will have the BNC
connector).
12. Attach the BNC plug on the other end of the adaptor
stalk to the matching BNC connector on the transmitter's top
plate. Line the plug's two side slots over the jack's protrud-
ing bumps and gently push down; then turn the BNC plug's
knurled ring clockwise until the connectors snap together.
(To remove: push down slightly and turn the BNC plug's
knurled ring counter-clockwise; pull the adaptor straight up
and off.)
In addition to the long forward throw of infrared light
from the main beam, the 360° emitter’s infrared light
will illuminate areas to the sides and back of the trans-
mitter like a table lamp.
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USING ANOTHER INPUT SOURCE:
Although the internal pressure zone microphone is one of
the best ways to pick up sounds within a room when no
other microphones are available, or when a single speaker
is positioned near the transmitter, there are situations
where other solutions are possible. Following are some
examples of alternative input sources:
To use a different microphone with the transmitter
instead of the internal microphone:
1. Plug the alternate microphone into the EXTERNAL INPUT
jack. The microphone cable must have a 1/4 inch/6.5 mm
phone plug and be an unbalanced line. Most dynamic mi-
crophones and self-powered electret condenser micro-
phones will work fine. There is no phantom power for the
mic available at the jack.
2. Move the selector switch next to the EXTERNAL INPUT
jack to the "MIC" position. Leaving the switch in the wrong
position won't damage the transmitter, but the input will be
so attenuated that it will be nearly impossible to hear any-
thing.
As soon as the external microphone is plugged in, the
internal microphone is automatically disabled. The
EXTERNAL INPUT MIC-LINE switch can be left in ei-
ther position when the internal microphone is used.
The switch has no effect if there is nothing is plugged
into the EXTERNAL INPUT jack.
To transmit a line level output from a microphone
mixer, audio or video recorder output, or other
similar device:
1. Plug the direct line into the EXTERNAL INPUT jack. The
cable must have a 1/4 inch/6.5 mm phone plug and be an
unbalanced line. Levels ranging from -10 dB through +4 dB
can be accepted. This covers most commonly encountered
devices.
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2. Move the selector switch next to the EXTERNAL INPUT
jack to the "LINE" position. Leaving the switch in the wrong
position won't damage the transmitter, but the sound will be
overloaded and distorted.
As soon as the external line source is plugged in, the
internal microphone is automatically disabled. The
EXTERNAL INPUT MIC-LINE switch can be left in ei-
ther position when the internal microphone is used.
The switch has no effect if there is nothing is plugged
into the EXTERNAL INPUT jack.
USING THE OUTPUT JACK:
Whatever sound is being sent from the infrared emitter,
whether it is picked up by the internal microphone or from
an external mic or line source, that sound is available at the
output jack. Though this feature is not directly a part of the
infrared transmitting system, it provides a convenient way
to record the proceedings, or feed a sound reinforcement
system. The level of the output will depend somewhat on
the nature of the sound being picked up, but the output jack
will drive most low impedance line inputs at levels of -10
dB, and with a little gain boost, +4 dB inputs. The output is
an unbalanced 1/4 inch/6.5 mm phone plug.
PLACEMENT:
In a lecture hall or standard audience seating situation the
infrared light will be emitted from the front panel light emit-
ting diodes. The invisible infrared light can be thought of as
coming from a point at the emitter array and spreading out-
wards as a cone of approximately 120° somewhat like a
wide-angle flashlight or headlight beam. Placement on a
lectern or table should be made so that the direct beam
"washes" over as much of the audience as possible. Ide-
ally the transmitter should be somewhat above and facing
the audience. The added height permits listeners further
back to have a less obstructed line-of-sight connection to
the transmitter without being blocked by people in seats
ahead of them. In practice, the stage in a lecture hall or
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small auditorium will provide the needed height. In a hotel
meeting room or other similar location, the infrared light is
likely to bounce off of a low ceiling and still reach the listen-
ers' headsets. The central lobe of the main beam will pro-
vide a direct signal at least 50 to 75 feet back, and about 25
to 35 feet to the sides at 60° off center. Depending on the
reflective qualities of the room, these figures can be even
better.
When the listeners are seated in-the-round such as around
a conference table in hearing rooms or in a court of law,
the 360° omnidirectional emitter provides additional cover-
age to the sides and behind the transmitter. In a confer-
ence the transmitter should be placed in the middle of a
conference table which places the 18 small emitters in a
horizontal plane above any surface clutter on the table. It
should be noted that the main transmitter beam is still trans-
mitting. If it can be aimed at a light colored wall or curtains,
its reflected backscatter will provide better fill. The 360°
omnidirectional emitter will transmit in a circular pattern with
the best signal in a 15 to 20 foot radius (a 30 to 40 foot di-
ameter). In actual use better ranges can often be achieved,
especially if the front throwing main emitter is aimed for its
best effect.
For courtroom use the internal microphone is capable of
providing good acoustical pickup of the trial participants
with a minimum of setup time and fuss. However in court-
rooms that are already equipped with sophisticated micro-
phone systems for public address and/or transcription re-
cording sometimes better intelligibility might be achieved if
the assistive listening transmitter is fed from the existing mi-
crophone mixer. Please see the section on Using An-
other Input Source for additional details. The Remote
Mute Control is used to silence the audio signal from the
transmitter in order to insure privacy during side bar or
other confidential conversations. Please see the section on
The Remote Mute Control for additional details.
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TECHNICAL SPECIFICATIONS: MODEL SC-186Kx2
•Microphone: Sound Choice design pressure zone electret
(standard) or Crown® PZM-11 capsule (special order).
•Preamplifier: Low-noise BiFET circuitry with automatic gain
control and peak limiting
•1/4" Input Jack switchable for mic or line levels
(unbalanced)
•1/4" Line Output Jack (unbalanced)
•Optional BNC Connector available for 360 degree Emitter
Disk
•MiniDIN Connectors for optional Remote Mute Switch and
Slave Transmitter
•Equalization: Low end rolloff below 150 Hz; 50 microsec-
ond pre-emphasis
•Infrared transmission: 880 nm, IEC 764 Standard 2.3 mHz,
2.8 mHz FM optical carrier Optical output: main IR beam ar-
ray greater than 450 mW; approximately 120 degree beam
dispersion
•AC Power requirements: 125 volts AC to 16 volts AC, 1
Amp UL/ CSA approved wall block transformer (included)
•Dimensions: 6 1/2" x 5" x 1 3/4" (16.5 cm x 12.7 cm x 4.5
cm); 1.4 lbs. (0.63 kg)
PZM®is a registered trademark of Crown International, Elkhart, Indiana.
MISCELLANEOUS NOTES:
•Under typical operating conditions, the front plastic emitter
cover of this transmitter may become slightly warm to the
touch. This is normal and poses no hazard or fire risk.
•The black plastic top plate is constructed of a material
known as foam PVC. It provides superior acoustic qualities
for the microphone mounted on its surface. This material is
somewhat uneven in its appearance and may exhibit some
cosmetic irregularities. This is normal and expected.
•The transmitter should never be immersed in water, but the
exposed plastic, metal and wood surfaces may be cleaned
with a lightly dampened cloth. Solvents should not be used
as cleaning agents.
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Limited Warranty
SOUND CHOICE warrants this product to the original purchaser,
against defects in material or workmanship as follows:
WARRANTY PERIOD:
Sound Choice products are warranted for the period of THREE
YEARS from the date of original purchase. Sound Choice will, at its op-
tion, repair the defective product at no cost to you, or replace the defec-
tive product with new or remanufactured functionally equivalent product
of equal value.
In addition, Sound Choice will supply labor and new or rebuilt replace-
ments for defective parts for a period of THREE YEARS from the date
of original purchase.
HOW TO OBTAIN SERVICE:
To obtain warranty servicing during the above described period, contact
Sound Choice at [phone] or [email protected].
WHAT YOU MUST DO:
The unit must be shipped, freight prepaid, or delivered to Sound Choice
to render warranty service. The unit must be packaged in such a way as
to reasonably protect it from possible shipping damage. Proof of pur-
chase in the form of the retailer's bill of sale or invoice must be con-
firmed before return with a detailed description of the problem.
WHAT WE WILL NOT COVER:
This warranty will not apply if the unit has been previously altered, re-
paired, or serviced by anyone other than a service center authorized by
Sound Choice; the serial number of the unit has been altered or re-
moved; the unit has been subject to accident, misuse, abuse or oper-
ated contrary to the instructions contained in the accompanying man-
ual.
EXCEPT TO THE EXTENT PROHIBITED BY LAW, THIS
SHALL BE THE EXCLUSIVE WRITTEN WARRANTY OF THE
ORIGINAL PURCHASER AND NEITHER THIS WARRANTY
NOR ANY OTHER WARRANTY, EXPRESS OR IMPLIED, IN-
CLUDING A WARRANTY OF MERCHANTABILITY, SHALL
EXTEND BEYOND SAID PERIOD. SOUND CHOICE SHALL
NOT BE LIABLE FOR ANY LOSS OR DAMAGE, DIRECT OR
CONSEQUENTIAL, ARISING OUT OF, OR INABILITY TO
USE THIS PRODUCT.
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