Lightspeed Technologies 820Ir Users Manual 820_MANUAL

820iR to the manual a4377bd6-640f-479e-8900-a48a1264ca16

2015-02-09

: Lightspeed-Technologies Lightspeed-Technologies-820Ir-Users-Manual-574051 lightspeed-technologies-820ir-users-manual-574051 lightspeed-technologies pdf

Open the PDF directly: View PDF .
Page Count: 26

Download
Open PDF In Browser	View PDF

820iR

LightSPEED

Classroom Amplification System

L i g h t S P E E D Te c h n o l o g i e s , I n c .
1 1 5 0 9 S W H e rm a n R d
Tu a l a t i n , O R 9 7 0 6 2
800.732.8999
w w w. l i g h t s p e e d - t e k . c o m

User Manual

820iR User Manual

USER NOTES

820iR User Manual

SAFETY INSTRUCTIONS
7. Power Sources—This LightSPEED

CAUTION

product should be connected to a
power supply only of the type

RISK OF ELECTRIC SHOCK DO NOT OPEN

described in these operation
instructions or as marked on this

CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK
DO NOT REMOVE COVER (OR BACK)
NO USER-SERVICEABLE PARTS INSIDE
REFER SERVICING TO QUALIFIED PERSONNEL
The lightning ﬂash with arrowhead symbol
within an equilateral triangle is intended to alert
the user to the presence of uninsulated “dangerous voltage” within the product’s enclosure, that
may be sufﬁcient magnitude to constitute a risk
of electric shock.
The exclamation point within an equilateral
triangle is intended to alert the user to the presence of important operating and maintenance
(servicing) instructions in the literature accompanying the appliance.

1. Read Instructions—All the safety

and operation instructions should
be read before this LightSPEED
product is operated.
2. Retain Instructions—The safety and

operating instructions should be
kept for future reference.
3. Heed Warning—All warnings on

this LightSPEED product and in
these instructions should be
followed.

LightSPEED product.
8. Power Cord Protection—Power supply

cords should be routed so that
they are not likely to be walked upon
or pinched by items placed upon or
against them.
9. Object and Liquid Entry—Care should

be taken so that objects do not fall
onto and liquids are not spilled into
the inside of this LightSPEED product.
1 0. Damage Requiring Service—This

LightSPEED product should be
serviced only by qualiﬁed service
personnel. The user should not
attempt to service this LightSPEED
product.
11. Prevent Electric Shock—do not use

this polarized plug with an extension
cord, receptacle or other outlet
unless the blades can be fully
inserted to prevent blade exposure.

4. Follow Instructions—All operating

and other instructions should be
followed.
5. Water and Moisture—This Light-

SPEED product should not be used
near water.
6. Heat—This LightSPEED product

should be situated away from heat
sources such as radiators, etc.
21 | 820iR User Manual

820iR User Manual | i

820iR User Manual

DAILY USE INSTRUCTIONS

USER NOTES

TURN ON THE 820iR

Record your system serial numbers and
purchase information. This is helpful
when ordering additional components,
accessories, and/or warranty service.

LES 820iR Classroom Amplification System
B VOLUME

A VOLUME
IR

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ALD VOLUME

Components

POSITION THE LIGHTMIC

Serial Number

Unplug the LightMic from the

820iR

charging cable and place it around
your neck. Adjust the neck strap so
LT-71

the top of the microphone rests just

Microphones

below your collarbone.
AUDIO INPUT

TV/VCR

250

CD/DVD

400

700

2.06/2.54

SPEAKER OUTPUTS

DC
POWER

CHARGERS

24V
DC

1K
+10

1K4

2K5

6K3

SENSOR INPUT

Sensors

SENSOR
SHORT

-10

LT-71

Speakers

TURN ON THE LIGHTMIC

CHARGE BATTERIES

Turn the microphone ON using the

Plug the LightMic back into the

ON/OFF switch on the side of

charging cable to recharge at the

the LightMic and speak normally.

end of the day.
Purchase Information

OFF

Your School/Organization
District

LT-71

A CH B

Purchase Date
AUDIO INPUT

TV/VCR

250

CD/DVD

2.06/2.54

SPEAKER OUTPUTS

DC
POWER

24V
DC

CHARGERS

400

700

1K
+10

1K4

2K5

6K3

SENSOR INPUT

0
-10

SENSOR
SHORT

Invoice

ii | 820iR User Manual

820iR User Manual | 20

820iR User Manual

INDIVIDUAL COMPONENTS & OPTIONAL ACCESSORIES
Part Number

Description

RX-820

Infrared receiver/ampliﬁer/mixer w/built-in charger

LT71

LightMic™ rechargeable microphone/transmitter
w/lavaliere cord, batteries and charging cable

HM70

Handheld microphone/transmitter w/batteries and
charging cable

BA-NH1
AC-TCC7

Rechargeable AA battery (Nickel Metal Hydride)
Charging cable for LT-71 and HM-70 microphones

AC-LTCB

Lavaliere cord for LT-71

PS-24V-2.5

Power supply/battery charger for 820iR

SR70F
AC-71CC
SPEAKERS

820iR User Manual

TABLE OF CONTENTS
820iR CLASSROOM AMPLIFICATION SYSTEM
Safety Instructions

Daily Use Instructions

820iR Classroom Ampliﬁcation System

System Components

System Installation

Unpacking Your System

Location of the Receiver/Ampliﬁer

IR Sensor Placement

IR Sensor Installation

Suspended Ceiling Mount

Wall/Solid Ceiling Mount

Speaker Installation

Front Panel Controls

Infrared sensor with cable and wall or ceiling mounting
bracket

Rear Panel Controls

LightMic Controls and Connections

Cradle charger

Initial Setup

Contact LightSPEED at 800.732.8999 for loudspeaker
information

Optional Accessories

Finalizing Receiver/Ampliﬁer

Final Check

System Operation
Turning the System On

9
9

Noise-canceling headset microphone used
with LT-71

Charging the LightMic

System Installation Diagram

BC-TXLT

Wall charger

Input from External Audio Equipment

Output to Personal FM Transmitter

AC-800WB

Wall shelf

Operating the Optional HM-70 Handheld Mic

Charging the HM-70

CA-RCA6

6’ dual RCA audio cable

Tips on Classroom Ampliﬁcation

CA-RCA24

24’ dual RCA audio cable

CA-MMC3535

3.5 mm mono to 3.5 mm mono audio cable

MC-TK250LTM

CA-MMC2535
19 | 820iR User Manual

Audio patch cable (2.5 mm mono to 3.5 mm mono)

Warranty Statement

Troubleshooting Guide

System Speciﬁcations

Individual Components and Optional Accessories

User Notes

820iR User Manual

820iR CLASSROOM AMPLIFICATION SYSTEM
LES 820iR Classroom Amplification System
B VOLUME

A VOLUME
IR

POWER

TV/VCR

AUDIO INPUT

24V
DC

AUDIO INPUT VOLUME

250

CD/DVD

2.06/2.54

CHARGERS

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

TV/VCR

DC
POWER

SYSTEM SPECIFICATIONS
OVERALL SPECIFICATIONS

820iR Receiver/Ampliﬁer

SPEAKER OUTPUTS

820iR User Manual

400

700

1K
+10

1K4

12 W per channel (24 W total)

Ampliﬁer Frequency Response

40 Hz to 20 kHz ±3 dB

Carrier Frequencies (IR)

2.06/2.54; 3.2/3.7 MHz

Signal-to-Noise Ratio

> 73 dB

Dynamic Range

> 73 dB

Maximum Deviation

±50 dB

ALD VOLUME

2K5

6K3

SENSOR INPUT

0
-10

Power Output

SENSOR
SHORT

RECEIVER SPECIFICATIONS

LT-71

SR-70F
iR Sensor
LT-71™
LightMic
Transmitter

(Optional) HM-70
Handheld Microphone

Receiver Type

Superheterodyne

Receiver Sensitivity

6 µV for 60 dB S/N

Image and Spurious Rejection

> 70 dB

Dimensions (W x D x H)

17.3” x 8.5” x 1.75”

Weight

7 lbs.

TRANSMITTER SPECIFICATIONS
Audio Distortion

Congratulations on your purchase

<1%

The 820iR is a two-channel receiver

Built-in Microphone

Uni-directional Electret
2 AA NiMH Rechargeable

of the 820iR Classroom Ampliﬁca-

ampliﬁer that allows the use of up

Battery Power (1-year warranty)

tion System! This simple, yet power-

to two microphones simultaneously

Inputs

ful technology provides crystal-clear

and up to two additional audio input

sound throughout the classroom,

sources (such as TV, VCR, DVD, CD,

Dimensions (W x D x H)

1.375” x .75” x 4.625”

allowing every child to hear every

MP3, etc.). In addition, LightSPEED

Weight

3.7 oz

word every time.

offers various speaker options that

As the teacher speaks into the
LightMic pendant-style transmitter,
his or her voice is transmitted to the

are included with your system to pro-

Mic Level 3.5 mm
Line Level 3.5 mm

IR SENSOR SPECIFICATIONS

vide optimal sound in rooms of
all shapes and sizes.

Working Range

Up to 1600 square feet
per sensor

820iR and then ampliﬁed through the

The LT-71 LightMic is a wireless, pen-

loudspeaker(s). The standard system

dant-style transmitter. This two-chan-

includes the 820iR infrared receiver/

nel, rechargeable unit is clipped to a

ampliﬁer, LT-71 LightMic™ transmit-

lavaliere cord and worn around the

Dimensions (W x D x H)

4.25” (Diam.) x 2.0” (H)

ter, SR-70 infrared sensor and speaker

neck for teacher use, or it can be used

Weight

4.5 oz

package.

like a standard handheld microphone

Cable

50 ft., Plenum-rated

Mounting

Ceiling clip/Wall bracket

for the students to pass around when
speaking.
1 | 820iR User Manual

820iR User Manual | 18

820iR User Manual

TROUBLESHOOTING GUIDE

820iR User Manual

SYSTEM COMPONENTS

Note: Most problems are directly related to low battery power. Please
run through the “Battery Check” items ﬁrst. For remaining troubleshooting, use known good, fully-charged batteries.

LES 820iR Classroom Amplification System
B VOLUME

A VOLUME

Battery Check
• Conﬁrm batteries are charged

each night.
• Make sure the LT-71 is turned off

while charging so that it will attain
a full charge. Full charge will last
eight hours.
• Make sure the charge cord is

connected to the cradle charger.
• Inspect the battery contacts. Clean

and adjust if necessary.
Hearing Static
• Ensure sensor is in optimum

location (refer to sensor placement
in manual). A single sensor will
cover a 1600 sq. ft. enclosed
classroom.

No Sound From Speaker

POWER

• Turn the 820iR on. Conﬁrm that

the POWER light located on the
front panel switch is on.
• Conﬁrm signal is being received

at the ampliﬁer. The IR signal
light will be lit (red) indicating a
signal is being received.

TV/VCR

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ASSISTIVE LISTENING

ALD VOLUME

820iR Infrared Receiver/Ampliﬁer

Sensor Cable

• Conﬁrm microphone is function-

ing. Next to the IR signal light is
the AF signal light. This light will
ﬂicker (green) as audio is picked
up by the microphone indicating
activity.

CD/DVD

LT-71

SR-70F Infrared
Sensor

• Conﬁrm that the speaker wires

are connected correctly to the
back of the 820iR (refer to
speaker install guide).

Power Supply

• Ensure that no other LT-71/HM70 is

operating on the same channel.
• If an external microphone is in use,

try another LightMic that is known
to be working (if available) to isolate
the problem. If static persists with
“known good” microphone, the
LT-71 input jack has damage and
will need service.
Low Volume or Feedback

LT-71 LightMic™
Transmitter
Speakers and
Speaker Wire

• Ensure microphone is positioned
appropriately, just below the collarbone. If a headset microphone is in
use, the end of the mic boom
should be positioned at the corner
of the mouth.
• Check volume level on the ampli-

Optional HM-70 Handheld Microphone

ﬁer. If the volume is too high, feedback WILL occur. Adjust accordingly.

If you review these instructions and still have questions, write down the serial
number and model number of your system and call LightSPEED Technical Services
at 800.732.8999, 6:30 a.m. – 5 p.m. PST.

17 | 820iR User Manual

Helpful
Hint

Keep ALL packaging materials. If the system
must be returned, it will be quick, convenient
and undamaged.

820iR User Manual | 2

820iR User Manual

TIPS ON CLASSROOM AMPLIFICATION

SYSTEM INSTALLATION
Unpacking Your System

Location of the Receiver/Ampliﬁer

• Ensure that you have received
all of the components of
your system.

Place the 820iR on a ﬂat surface like a
bookcase, countertop or optional LightSPEED wall shelf (part#AC-800WB).

• 820iR Receiver/Ampliﬁer
and power supply
• LT-71 LightMic™ Transmitter
• SR-70F Infrared Sensor
and cable

• Select a location that is close to a

standard wall electrical outlet.
• Wires will be routed back to the
ampliﬁer, so select a location that is
free from obstructions that may make
routing wire difﬁcult. (Example: under
a whiteboard or bulletin board.)

• Speaker(s) and speaker wire

3
4

IR Sensor Placement
Sensor location is very important for
optimum performance of the 820iR
Classroom Ampliﬁcation System.
• BEST: On the ceiling at or near the
middle of the classroom.

Speak in a natural voice. A normal conversational speech level

will provide an adequate signal. It is not necessary to increase
the intensity of your voice—the ampliﬁcation system provides
adequate ampliﬁcation (approximately 5 – 10 dB) above
ambient room noises.
Avoid wearing jewelry that may rub or bump against
the microphone.

Turn the LightMic off during private conversations with a student,

parent, or other classroom visitor. You can also cover the LED
lens on top of the LightMic to block the signal.
Recharge batteries each night. When recharged nightly, operating
time (actual usage) for the transmitters will last through a typical
school day.

Five-year Limited Warranty
< GOOD

< BEST

• GOOD: High and centered on the
long wall.
• AVOID: Locations in corners, on
walls at heights lower than 7 feet,
or in places where the line of sight is
or could be obstructed.

LightSPEED Classroom Ampliﬁcation Systems are guaranteed against malfunction due to
defects in materials and workmanship for a period of FIVE (5) YEARS, beginning at the date
of the purchase invoice. If such malfunction occurs, the product will be repaired or replaced
(at LightSPEED’s option) without charge during the period and under the limitations stipulated
in the data sheet or the user’s manual.
1. Limited exclusions speciﬁcally apply to all microphone elements, rechargeable
batteries, battery chargers and their assemblies, as well as external cables and wires.
2. Warranty on microphones/microphone elements is limited to original manufacturer’s
warranty (usually ONE (1) YEAR).
3. Warranty on LightSPEED NiMH AA rechargeable batteries is ONE (1) YEAR.
3. Warranty on LightMic’s internal microphone is FIVE (5) YEARS.

Helpful Hint
Fine-tuning the Graphic Equalizer:
1. Verify that the EQ is set to match the recommended setting for the speciﬁc
speakers installed in the classroom (settings included with the speaker install guide).
2. Walk around room (near speakers) and listen for squealing or feedback.

4. Prepaid shipping label provided by LightSPEED factory or an authorized warranty
service center.
5. Warranty does not extend to ﬁnish, appearance items, or malfunctions due to abuse or
operation other than speciﬁed conditions, nor does it extend to incidental or consequential
damages. Repair by other than LightSPEED or its authorized service agencies will void this
guarantee. Information on authorized service agencies is available from LightSPEED
Technologies, Inc.

3. Lower the 2K5 and/or 4K sliders if a high-pitched squealing is present.
4. Lower the 400 or 700 sliders if a low-pitched ring is present.
5. Reduce volume if feedback is still present.

3 | 820iR Users Manual

Our Service Department (800.732.8999, 6:30 a.m. – 5 p.m.,
PST) will handle all your repair/replacement needs.
820iR Users Manual | 16

820iR User Manual

CHARGING THE HM-70 HANDHELD MIC

IR SENSOR INSTALLATION
Suspended Ceiling Mount

AUDIO INPUT

TV/VCR

250

CD/DVD

2.06/2.54

SPEAKER OUTPUTS

DC
POWER

24V
DC

CHARGERS

400

700

1K
+10

1K4

2K5

6K3

SENSOR INPUT

wall
mounting
strip

0
-10

Wall/Solid Ceiling Mount

SENSOR
SHORT

c-clip
sensor jack

1. Lift the ceiling tile nearest the

1. Ensure the HM-70 handheld

microphone is turned OFF (ON/OFF
switch on the side of the unit).
The 820iR can be left on, but must
be connected to AC power in order
to charge the microphone.
2. Connect the loose end of the

charging cable into the jack labeled
CHARGER on the side of the HM-70.
Connect the larger end of the
charging cable to one of the
CHARGERS jacks on the back of the

3. The power indicator light next to

the power switch glows green when
the cable is connected and charging correctly. The light goes out
when fully charged. Batteries
will charge in 8 to 12 hours. A fully
charged battery will run for up to 8
hours of continuous operation.
4. The HM-70 can remain charging

for up to 10 days. Overcharging
will shorten battery life.

820iR. The HM-70’s rechargeable
batteries are factory installed.

grid rail in your desired sensor
location. Guide one side of the
C-clip over one edge of the grid
rail. Providing ﬁrm support to the
back of the grid rail with one hand
(to prevent bending), ﬁrmly and
carefully snap the second side of
the C-clip over the edge of the rail.
2. Uncoil sensor wire. Connect one

end of the sensor cable to the plug
on the sensor. Loosely secure wire
overhead and route it back to the
820iR.
3. Connect the other end of the

sensor cable into one the sensor
input on the back of the 820iR.

1. Screw the plastic mounting

strip to a place high on the
wall or in the middle of the solid
ceiling. Mount the strip horizontally as shown above.
2. Firmly snap the C-clip on the back

of the IR sensor onto the plastic
mounting strip with the sensor
plug hanging down (if a wall
mount) or toward the receiver
location (if ceiling mount).
3. Uncoil the sensor wire. Screw one

end of the sensor cable to the
plug on the sensor. Route the
wire back to the 820iR,
securing it along the way.
4. Connect the other end of the

sensor cable to the sensor
input on the back of the 820iR.

Speaker Installation
1. Locate the speaker installation

instructions packed with your
speaker(s).

Helpful
Hint
15 | 820iR User Manual

The HM-70 does not use a cradle for charging.
The charging cable must be plugged directly
into the charging jack in the transmitter.

2. Follow instructions and mount

Speaker Install
Instructions

speaker(s).
3. Return to this manual to complete

the set up of your system.

820iR User Manual | 4

820iR User Manual

FRONT PANEL CONTROLS

OPERATING THE OPTIONAL HM-70 HANDHELD MIC
6

LES 820iR Classroom Amplification System

POWER

B VOLUME

A VOLUME
AF

WIRELESS MICROPHONE VOLUME

820iR User Manual

TV/VCR

LES 820iR Classroom Amplification System
CD/DVD

5
AUDIO INPUT VOLUME

B VOLUME

A VOLUME

ASSISTIVE LISTENING

POWER

ALD VOLUME

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ALD VOLUME

3
1. POWER Switch/POWER Indicator:

This switch is used to turn the
820iR ON (switch up), or OFF
(switch down). When the POWER
switch is in the ON position, the
red POWER light will glow.
2. IR Indicators (IR): These lights will

glow red when the corresponding
microphone is turned on. This light
conﬁrms the 820iR is receiving the
infrared signal.
3. AF Indicators (AF): These lights

ﬂash green when audio (voice)
from the microphone is detected.

4. A VOLUME: Controls the volume

level of the teacher microphone
that is switched to Channel A.
Rotating the knob clockwise
increases output level.
5. B VOLUME: Controls the volume

level of the optional second
microphone that is switched to
Channel B. Rotating the knob
clockwise increases output level.
6. AUDIO INPUT VOLUME:
• TV/VCR: Controls the volume of

a TV/VCR connected to the
TV/VCR INPUT.
• CD/DVD: Controls the volume

of a CD/DVD player connected
to the CD/DVD INPUT.
7. ASSISTIVE LISTENING VOLUME:

Controls the volume level of an
assistive listening device.

MUTE

(Center Position)

The Channel A/B switch is located
inside the battery compartment.
The switch is set to Channel B at
the factory.
1. Slide the power switch on the side

of the HM-70 all the way up. The
power indicator LED will glow red
and stay on.
2. The center position of the power

switch is MUTE. When in this mode,
the HM-70 is transmitting a signal,
but no audio can be heard through
the system. This is useful if you
wish to temporarily turn audio off
during a private conversation.

5 | 820iR User Manual

OFF

3. Grip the barrel of the HM-70 in the

center section just below the power
switch. Avoid gripping the HM-70
around the bottom, covering the
infrared emitters circling the base.
This could interrupt signal transmission from the microphone to
the receiver.
4. Speak directly into the microphone

at a normal level. Slowly increase
the B VOLUME until you can just
hear your voice.
5. Slide the switch to the OFF position

to turn off the HM-70. (Make sure the
power indicator light is off.)

820iR User Manual | 14

820iR User Manual

OUTPUT TO PERSONAL FM TRANSMITTER
1. Turn the ALD (Assistive Listening Device) volume control on

the front panel all the way down (fully counterclockwise).

820iR User Manual

REAR PANEL CONTROLS
4

AUDIO INPUT

TV/VCR

CD/DVD

2.06/2.54

SPEAKER OUTPUTS

LES 820iR Classroom Amplification System
B VOLUME

A VOLUME
IR

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

DC
POWER

24V
DC

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

CHARGERS

binding post connectors are used to
connect the 820iR to the loudspeakers.
Depending on speaker, all outputs
may not be used.

products differ in connector size and
shape. The LightSPEED LES-370 Personal

2. DC POWER: Plug the 24 V power

FM System requires a 3.5 mm to 3.5 mm
patch cable (part# CA-MMC3535, not included).

supply into this jack.
3. CHARGERS: These jacks charge the

LES 820iR Classroom Amplification System

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

700

1K
+10

1K4

2K5

6K3

SENSOR INPUT

SENSOR
SHORT

-10

1. SPEAKER OUTPUTS (1–4): These

jack on the device as many manufacturers’

B VOLUME

400

ALD VOLUME

2. Determine the size and type of audio input

A VOLUME

250

LightMic(s) and optional handheld
microphone with the supplied charging cable(s).

4. AUDIO INPUTS:
• TV/VCR: Accepts stereo signal

from TV/VCR via RCA cable.
• CD/DVD: Accepts stereo signal

from CD/DVD player via RCA cable.
5. 8-BAND GRAPHIC EQUALIZER: The

sliding controls adjust the levels of
the various audio frequencies. This
allows the installer to properly
equalize the system to produce
optimum sound quality.

ALD VOLUME

6. SENSOR INPUT: The IR sensor
3. Connect a patch cable from the ALD’s

microphone jack or AUX input to the 3.5
mm “ASSISTIVE LISTENING” jack on the
front of the 820iR.

cable connects to the sensor input.
Connect additional sensors to the
820iR to cover large or oddshaped classrooms.
7. SENSOR SHORT: This LED glows

when there is a short in one of the
sensor cables.
4. Adjust the volume control on the ALD’s receiver to maximum

output. NOTE! This is to set the maximum allowable signal
from the 820iR.
5. With the 820iR and ALD turned on, speak into the LightMic and slowly

adjust the corresponding “ALD VOLUME” control until the appropriate
audio level is attained in the ALD’s receiver headphones.

13| 820iR User Manual

820iR User Manual | 6

820iR User Manual

LIGHTMIC CONTROLS AND CONNECTIONS

820iR User Manual

INPUT FROM EXTERNAL AUDIO EQUIPMENT
Below are instructions on how to connect an external audio device
like a TV/VCR, CD/DVD or computer.

1
1

LES 820iR Classroom Amplification System
B VOLUME

A VOLUME

LT-71

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ALD VOLUME

1. Turn the audio input volume controls on the front panel all the

way down (fully counterclockwise).

AUDIO INPUT

TV/VCR

250

CD/DVD

400

2.06/2.54

DC
SPEAKER OUTPUTS
POWER

CHARGERS

24V
DC

700

1K
+10

1K4

2K5

6K3

SENSOR INPUT

0
-10

SENSOR
SHORT

2
2. Connect a patch cable (not included)

1. ON/OFF/MUTE Switch: This switch,
located on the side of the LightMic,
turns the unit on or off/mute.
2. Channel Select Switch (CH A/B):
This switch allows for selection
between Channel A or B. If you are
using a single microphone/transmitter for your system, we recommend
using Channel A.
3. Power/Charge LED Indicator: The
light glows blue when the LightMic
is powered ON, red when plugged
into the charging cable.
4. External Microphone Input (MIC):
Use the 3.5 mm MIC jack for the
optional TK-250 headset microphone
(part# MC-TK250LTM).

7 | 820iR User Manual

5. Auxiliary (AUX): Plug a laptop, MP3
player or other audio source into
this jack to wirelessly transmit the
audio signal to be played through
the 820iR.
6. Charger Input (CHARGER): Plug
the charging cable from the 820iR
into this jack for daily charging.
The LED on the front will glow red
to indicate charging.

from the audio source in the corresponding audio input jacks on the
back of the 820iR.

3
LES 820iR Classroom Amplification System
B VOLUME

A VOLUME
IR

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ALD VOLUME

3. With both the 820iR and audio source power on, adjust the

corresponding volume control on the front panel until the
desired level is achieved. NOTE! Be careful to not overdrive the
volume to the loudspeaker(s), as this can cause potential damage.

820iR User Manual |12

820iR User Manual

SYSTEM INTEGRATION DIAGRAM

820iR User Manual

INITIAL SET-UP
FINALIZING RECEIVER/AMPLIFIER CONNECTIONS
1. Ensure the power switch is in the “OFF” position
and all front panel volume controls are turned
fully counter-clockwise.

2. Ensure speaker wire
connections are secure
and not frayed.

Video In

Projector
Projector

LES 820iR Classroom Amplification System

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

B VOLUME

A VOLUME
IR

WIRELESS MICROPHONE VOLUME

ALD VOLUME

AUDIO INPUT VOLUME

1
IR Sensor

IR Transmission

LT-71

3. Connect the charging cables to yellow charging jacks labeled
“CHARGERS.” The loose end will be connected to the charger
input on the microphone.

Teacher’s
Microphone

AUDIO INPUT

TV/VCR

250

CD/DVD

400

700

2.06/2.54

SPEAKER OUTPUTS

DC
POWER

CHARGERS

24V
DC

1K
+10

1K4

2K5

6K3

SENSOR INPUT

SENSOR
SHORT

-10

Speaker(s)

4. Connect any auxiliary audio
sources to corresponding
labeled input. >>

Audio Out
Video Out

Video Out

AUDIO INPUT

TV/VCR

250

CD/DVD

400

700

1K
+10

2.06/2.54

SPEAKER OUTPUTS

DC
POWER

CHARGERS

24V
DC

1K4

2K5

6K3

SENSOR INPU

0
SENSOR
SHORT

-10

5. Ensure sensor cable is attached
securely.
DVD/VCR

Audio Out

LES 820iR Classroom Amplification System
B VOLUME

A VOLUME
IR

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ALD VOLUME

6. Connect DC end of power supply
to the black power jack labeled
“DC POWER.”

AUDIO INPUT

TV/VCR

250

CD/DVD

2.06/2.54

DC
SPEAKER OUTPUTS
POWER
24V
DC

CHARGERS

400

700

1K
+10

1K4

2K5

6K3

SENSOR INPUT

0
-10

SENSOR
SHORT

7. Connect the black AC power cable
from the power supply to a wall outlet.

FINAL CHECK
1. Ensure all cables are appropriately routed out of walking paths and work areas to
prevent safety hazards to individuals in the room.

LightSPEED ampliﬁer controls the volume of each source
individually (one volume control for each source).

11 | 820iR User Manual

2. The ampliﬁer packing material should be kept for warranty shipping purposes.
Dispose of remaining system-packing material in the appropriate refuse containers.
Leave microphones charging so they are ready for use. Microphones will need to be
charged on a daily basis.

820iR User Manual | 8

820iR User Manual

SYSTEM OPERATION

CHARGING THE LIGHTMIC

TURNING THE SYSTEM ON
1. Turn the 820iR switch to the ON
position. The red LED on the switch
will glow. >>

LES 820iR Classroom Amplification System

1. Ensure that the LightMic is turned OFF.
B VOLUME

A VOLUME
AF

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

2. Connect one end of the charging cable to the

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

LightMic and the other end to one of the charger

ALD VOLUME

jacks on the back of the 820iR. The LED on the
2. Slip the LT-71 LightMic with lanyard

front of the LightMic will glow when fully charged.

around the neck and position the top of

3. Leave the LightMic plugged in overnight (8–10 hrs.)

the microphone just below the collarbone.

LT-71

Note: Positioning of the LightMic is critical

to obtain a full charge.

for proper volume adjustment.
AUDIO INPUT

TV/VCR

250

CD/DVD

400

700

2.06/2.54

3. Turn on the LightMic and set the operating

SPEAKER OUTPUTS

channel to “A.” This microphone will be
designated as the “Teacher Mic.”

A CH B

OFF

4. While speaking in a normal voice, >>
LES 820iR Classroom Amplification System
B VOLUME
A VOLUME
increase the A VOLUME level until
your voice is barely audible.
POWER
Remember! This equipment is
designed to supplement and distribute
the end user’s voice so they are able to speak at a conversational tone.
Having the volume set too high will result in feedback and listener fatigue.
IR

R
ADJ

TV/VCR

700

1K
+10

1K4

2K5

6. If a second student pass-around microphone
was purchased with system, repeat steps
3-4 but set the operating channel to “B.” >>
(If a HM-70 was purchased, see page 16.)
9 | 820iR User Manual

CD/DVD

AUDIO INPUT VOLUME

5. Once initial volume level is set,
walk around the room and listen for
SENSOR
SHORT
audio dropout
and overall audio
SENSOR INPUTS
0
quality. Fine-tuning the audio is
accomplished by making minor
-10
adjustments to the 8-Band Graphic
Equalizer on the back panel of the
receiver/ampliﬁer.
See page 3 for hints on setting the EQ.
400

CHARGERS

1K
+10

1K4

0
-10

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

250

DC
POWER

24V
DC

820iR User Manual

ALD VOLUME

Helpful Hint
Do not attempt to charge alkaline batteries.
They can overheat and expand, creating a
signiﬁcant hazard and damaging the LightMic.
(This is not covered by the warranty.)

A CH B

OFF

820iR User Manual | 10

820iR User Manual

SYSTEM OPERATION

CHARGING THE LIGHTMIC

TURNING THE SYSTEM ON
1. Turn the 820iR switch to the ON
position. The red LED on the switch
will glow. >>

LES 820iR Classroom Amplification System

1. Ensure that the LightMic is turned OFF.
B VOLUME

A VOLUME
AF

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

2. Connect one end of the charging cable to the

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

LightMic and the other end to one of the charger

ALD VOLUME

jacks on the back of the 820iR. The LED on the
2. Slip the LT-71 LightMic with lanyard

front of the LightMic will glow when fully charged.

around the neck and position the top of

3. Leave the LightMic plugged in overnight (8–10 hrs.)

the microphone just below the collarbone.

LT-71

Note: Positioning of the LightMic is critical

to obtain a full charge.

for proper volume adjustment.
AUDIO INPUT

TV/VCR

250

CD/DVD

400

700

2.06/2.54

3. Turn on the LightMic and set the operating

SPEAKER OUTPUTS

channel to “A.” This microphone will be
designated as the “Teacher Mic.”

A CH B

OFF

R
ADJ

TV/VCR

700

1K
+10

1K4

2K5

6. If a second student pass-around microphone
was purchased with system, repeat steps
3-4 but set the operating channel to “B.” >>
(If a HM-70 was purchased, see page 16.)
9 | 820iR User Manual

CD/DVD

AUDIO INPUT VOLUME

CHARGERS

1K
+10

1K4

0
-10

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

250

DC
POWER

24V
DC

820iR User Manual

ALD VOLUME

Helpful Hint
Do not attempt to charge alkaline batteries.
They can overheat and expand, creating a
signiﬁcant hazard and damaging the LightMic.
(This is not covered by the warranty.)

A CH B

OFF

820iR User Manual | 10

820iR User Manual

SYSTEM INTEGRATION DIAGRAM

820iR User Manual

INITIAL SET-UP
FINALIZING RECEIVER/AMPLIFIER CONNECTIONS
1. Ensure the power switch is in the “OFF” position
and all front panel volume controls are turned
fully counter-clockwise.

2. Ensure speaker wire
connections are secure
and not frayed.

Video In

Projector
Projector

LES 820iR Classroom Amplification System

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

B VOLUME

A VOLUME
IR

WIRELESS MICROPHONE VOLUME

ALD VOLUME

AUDIO INPUT VOLUME

1
IR Sensor

IR Transmission

LT-71

3. Connect the charging cables to yellow charging jacks labeled
“CHARGERS.” The loose end will be connected to the charger
input on the microphone.

Teacher’s
Microphone

AUDIO INPUT

TV/VCR

250

CD/DVD

400

700

2.06/2.54

SPEAKER OUTPUTS

DC
POWER

CHARGERS

24V
DC

1K
+10

1K4

2K5

6K3

SENSOR INPUT

SENSOR
SHORT

-10

Speaker(s)

4. Connect any auxiliary audio
sources to corresponding
labeled input. >>

Audio Out
Video Out

Video Out

AUDIO INPUT

TV/VCR

250

CD/DVD

400

700

1K
+10

2.06/2.54

SPEAKER OUTPUTS

DC
POWER

CHARGERS

24V
DC

1K4

2K5

6K3

SENSOR INPU

0
SENSOR
SHORT

-10

5. Ensure sensor cable is attached
securely.
DVD/VCR

Audio Out

LES 820iR Classroom Amplification System
B VOLUME

A VOLUME
IR

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ALD VOLUME

6. Connect DC end of power supply
to the black power jack labeled
“DC POWER.”

AUDIO INPUT

TV/VCR

250

CD/DVD

2.06/2.54

DC
SPEAKER OUTPUTS
POWER
24V
DC

CHARGERS

400

700

1K
+10

1K4

2K5

6K3

SENSOR INPUT

0
-10

SENSOR
SHORT

7. Connect the black AC power cable
from the power supply to a wall outlet.

FINAL CHECK
1. Ensure all cables are appropriately routed out of walking paths and work areas to
prevent safety hazards to individuals in the room.

LightSPEED ampliﬁer controls the volume of each source
individually (one volume control for each source).

11 | 820iR User Manual

820iR User Manual | 8

820iR User Manual

LIGHTMIC CONTROLS AND CONNECTIONS

820iR User Manual

INPUT FROM EXTERNAL AUDIO EQUIPMENT
Below are instructions on how to connect an external audio device
like a TV/VCR, CD/DVD or computer.

1
1

LES 820iR Classroom Amplification System
B VOLUME

A VOLUME

LT-71

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ALD VOLUME

1. Turn the audio input volume controls on the front panel all the

way down (fully counterclockwise).

AUDIO INPUT

TV/VCR

250

CD/DVD

400

2.06/2.54

DC
SPEAKER OUTPUTS
POWER

CHARGERS

24V
DC

700

1K
+10

1K4

2K5

6K3

SENSOR INPUT

0
-10

SENSOR
SHORT

2
2. Connect a patch cable (not included)

7 | 820iR User Manual

from the audio source in the corresponding audio input jacks on the
back of the 820iR.

3
LES 820iR Classroom Amplification System
B VOLUME

A VOLUME
IR

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ALD VOLUME

3. With both the 820iR and audio source power on, adjust the

corresponding volume control on the front panel until the
desired level is achieved. NOTE! Be careful to not overdrive the
volume to the loudspeaker(s), as this can cause potential damage.

820iR User Manual |12

820iR User Manual

OUTPUT TO PERSONAL FM TRANSMITTER
1. Turn the ALD (Assistive Listening Device) volume control on

the front panel all the way down (fully counterclockwise).

820iR User Manual

REAR PANEL CONTROLS
4

AUDIO INPUT

TV/VCR

CD/DVD

2.06/2.54

SPEAKER OUTPUTS

LES 820iR Classroom Amplification System
B VOLUME

A VOLUME
IR

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

DC
POWER

24V
DC

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

CHARGERS

binding post connectors are used to
connect the 820iR to the loudspeakers.
Depending on speaker, all outputs
may not be used.

products differ in connector size and
shape. The LightSPEED LES-370 Personal

2. DC POWER: Plug the 24 V power

FM System requires a 3.5 mm to 3.5 mm
patch cable (part# CA-MMC3535, not included).

supply into this jack.
3. CHARGERS: These jacks charge the

LES 820iR Classroom Amplification System

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

700

1K
+10

1K4

2K5

6K3

SENSOR INPUT

SENSOR
SHORT

-10

1. SPEAKER OUTPUTS (1–4): These

jack on the device as many manufacturers’

B VOLUME

400

ALD VOLUME

2. Determine the size and type of audio input

A VOLUME

250

LightMic(s) and optional handheld
microphone with the supplied charging cable(s).

4. AUDIO INPUTS:
• TV/VCR: Accepts stereo signal

from TV/VCR via RCA cable.
• CD/DVD: Accepts stereo signal

from CD/DVD player via RCA cable.
5. 8-BAND GRAPHIC EQUALIZER: The

sliding controls adjust the levels of
the various audio frequencies. This
allows the installer to properly
equalize the system to produce
optimum sound quality.

ALD VOLUME

6. SENSOR INPUT: The IR sensor
3. Connect a patch cable from the ALD’s

microphone jack or AUX input to the 3.5
mm “ASSISTIVE LISTENING” jack on the
front of the 820iR.

cable connects to the sensor input.
Connect additional sensors to the
820iR to cover large or oddshaped classrooms.
7. SENSOR SHORT: This LED glows

when there is a short in one of the
sensor cables.
4. Adjust the volume control on the ALD’s receiver to maximum

output. NOTE! This is to set the maximum allowable signal
from the 820iR.
5. With the 820iR and ALD turned on, speak into the LightMic and slowly

adjust the corresponding “ALD VOLUME” control until the appropriate
audio level is attained in the ALD’s receiver headphones.

13| 820iR User Manual

820iR User Manual | 6

820iR User Manual

FRONT PANEL CONTROLS

OPERATING THE OPTIONAL HM-70 HANDHELD MIC
6

LES 820iR Classroom Amplification System

POWER

B VOLUME

A VOLUME
AF

WIRELESS MICROPHONE VOLUME

820iR User Manual

TV/VCR

LES 820iR Classroom Amplification System
CD/DVD

5
AUDIO INPUT VOLUME

B VOLUME

A VOLUME

ASSISTIVE LISTENING

POWER

ALD VOLUME

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ALD VOLUME

3
1. POWER Switch/POWER Indicator:

This switch is used to turn the
820iR ON (switch up), or OFF
(switch down). When the POWER
switch is in the ON position, the
red POWER light will glow.
2. IR Indicators (IR): These lights will

glow red when the corresponding
microphone is turned on. This light
conﬁrms the 820iR is receiving the
infrared signal.
3. AF Indicators (AF): These lights

ﬂash green when audio (voice)
from the microphone is detected.

4. A VOLUME: Controls the volume

level of the teacher microphone
that is switched to Channel A.
Rotating the knob clockwise
increases output level.
5. B VOLUME: Controls the volume

level of the optional second
microphone that is switched to
Channel B. Rotating the knob
clockwise increases output level.
6. AUDIO INPUT VOLUME:
• TV/VCR: Controls the volume of

a TV/VCR connected to the
TV/VCR INPUT.
• CD/DVD: Controls the volume

of a CD/DVD player connected
to the CD/DVD INPUT.
7. ASSISTIVE LISTENING VOLUME:

Controls the volume level of an
assistive listening device.

MUTE

(Center Position)

The Channel A/B switch is located
inside the battery compartment.
The switch is set to Channel B at
the factory.
1. Slide the power switch on the side

of the HM-70 all the way up. The
power indicator LED will glow red
and stay on.
2. The center position of the power

5 | 820iR User Manual

OFF

3. Grip the barrel of the HM-70 in the

at a normal level. Slowly increase
the B VOLUME until you can just
hear your voice.
5. Slide the switch to the OFF position

to turn off the HM-70. (Make sure the
power indicator light is off.)

820iR User Manual | 14

820iR User Manual

CHARGING THE HM-70 HANDHELD MIC

IR SENSOR INSTALLATION
Suspended Ceiling Mount

AUDIO INPUT

TV/VCR

250

CD/DVD

2.06/2.54

SPEAKER OUTPUTS

DC
POWER

24V
DC

CHARGERS

400

700

1K
+10

1K4

2K5

6K3

SENSOR INPUT

wall
mounting
strip

0
-10

Wall/Solid Ceiling Mount

SENSOR
SHORT

c-clip
sensor jack

1. Lift the ceiling tile nearest the

1. Ensure the HM-70 handheld

microphone is turned OFF (ON/OFF
switch on the side of the unit).
The 820iR can be left on, but must
be connected to AC power in order
to charge the microphone.
2. Connect the loose end of the

charging cable into the jack labeled
CHARGER on the side of the HM-70.
Connect the larger end of the
charging cable to one of the
CHARGERS jacks on the back of the

3. The power indicator light next to

for up to 10 days. Overcharging
will shorten battery life.

820iR. The HM-70’s rechargeable
batteries are factory installed.

end of the sensor cable to the plug
on the sensor. Loosely secure wire
overhead and route it back to the
820iR.
3. Connect the other end of the

sensor cable into one the sensor
input on the back of the 820iR.

1. Screw the plastic mounting

strip to a place high on the
wall or in the middle of the solid
ceiling. Mount the strip horizontally as shown above.
2. Firmly snap the C-clip on the back

of the IR sensor onto the plastic
mounting strip with the sensor
plug hanging down (if a wall
mount) or toward the receiver
location (if ceiling mount).
3. Uncoil the sensor wire. Screw one

end of the sensor cable to the
plug on the sensor. Route the
wire back to the 820iR,
securing it along the way.
4. Connect the other end of the

sensor cable to the sensor
input on the back of the 820iR.

Speaker Installation
1. Locate the speaker installation

instructions packed with your
speaker(s).

Helpful
Hint
15 | 820iR User Manual

The HM-70 does not use a cradle for charging.
The charging cable must be plugged directly
into the charging jack in the transmitter.

2. Follow instructions and mount

Speaker Install
Instructions

speaker(s).
3. Return to this manual to complete

the set up of your system.

820iR User Manual | 4

820iR User Manual

TIPS ON CLASSROOM AMPLIFICATION

SYSTEM INSTALLATION
Unpacking Your System

Location of the Receiver/Ampliﬁer

• Ensure that you have received
all of the components of
your system.

Place the 820iR on a ﬂat surface like a
bookcase, countertop or optional LightSPEED wall shelf (part#AC-800WB).

• 820iR Receiver/Ampliﬁer
and power supply
• LT-71 LightMic™ Transmitter
• SR-70F Infrared Sensor
and cable

• Select a location that is close to a

• Speaker(s) and speaker wire

3
4

IR Sensor Placement
Sensor location is very important for
optimum performance of the 820iR
Classroom Ampliﬁcation System.
• BEST: On the ceiling at or near the
middle of the classroom.

Speak in a natural voice. A normal conversational speech level

Turn the LightMic off during private conversations with a student,

Five-year Limited Warranty
< GOOD

< BEST

• GOOD: High and centered on the
long wall.
• AVOID: Locations in corners, on
walls at heights lower than 7 feet,
or in places where the line of sight is
or could be obstructed.

3. Lower the 2K5 and/or 4K sliders if a high-pitched squealing is present.
4. Lower the 400 or 700 sliders if a low-pitched ring is present.
5. Reduce volume if feedback is still present.

3 | 820iR Users Manual

Our Service Department (800.732.8999, 6:30 a.m. – 5 p.m.,
PST) will handle all your repair/replacement needs.
820iR Users Manual | 16

820iR User Manual

TROUBLESHOOTING GUIDE

820iR User Manual

SYSTEM COMPONENTS

Note: Most problems are directly related to low battery power. Please
run through the “Battery Check” items ﬁrst. For remaining troubleshooting, use known good, fully-charged batteries.

LES 820iR Classroom Amplification System
B VOLUME

A VOLUME

Battery Check
• Conﬁrm batteries are charged

each night.
• Make sure the LT-71 is turned off

while charging so that it will attain
a full charge. Full charge will last
eight hours.
• Make sure the charge cord is

connected to the cradle charger.
• Inspect the battery contacts. Clean

and adjust if necessary.
Hearing Static
• Ensure sensor is in optimum

location (refer to sensor placement
in manual). A single sensor will
cover a 1600 sq. ft. enclosed
classroom.

No Sound From Speaker

POWER

• Turn the 820iR on. Conﬁrm that

the POWER light located on the
front panel switch is on.
• Conﬁrm signal is being received

at the ampliﬁer. The IR signal
light will be lit (red) indicating a
signal is being received.

TV/VCR

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ASSISTIVE LISTENING

ALD VOLUME

820iR Infrared Receiver/Ampliﬁer

Sensor Cable

• Conﬁrm microphone is function-

ing. Next to the IR signal light is
the AF signal light. This light will
ﬂicker (green) as audio is picked
up by the microphone indicating
activity.

CD/DVD

LT-71

SR-70F Infrared
Sensor

• Conﬁrm that the speaker wires

are connected correctly to the
back of the 820iR (refer to
speaker install guide).

Power Supply

• Ensure that no other LT-71/HM70 is

operating on the same channel.
• If an external microphone is in use,

LT-71 LightMic™
Transmitter
Speakers and
Speaker Wire

Optional HM-70 Handheld Microphone

ﬁer. If the volume is too high, feedback WILL occur. Adjust accordingly.

17 | 820iR User Manual

Helpful
Hint

Keep ALL packaging materials. If the system
must be returned, it will be quick, convenient
and undamaged.

820iR User Manual | 2

820iR User Manual

820iR CLASSROOM AMPLIFICATION SYSTEM
LES 820iR Classroom Amplification System
B VOLUME

A VOLUME
IR

POWER

TV/VCR

AUDIO INPUT

24V
DC

AUDIO INPUT VOLUME

250

CD/DVD

2.06/2.54

CHARGERS

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

TV/VCR

DC
POWER

SYSTEM SPECIFICATIONS
OVERALL SPECIFICATIONS

820iR Receiver/Ampliﬁer

SPEAKER OUTPUTS

820iR User Manual

400

700

1K
+10

1K4

12 W per channel (24 W total)

Ampliﬁer Frequency Response

40 Hz to 20 kHz ±3 dB

Carrier Frequencies (IR)

2.06/2.54; 3.2/3.7 MHz

Signal-to-Noise Ratio

> 73 dB

Dynamic Range

> 73 dB

Maximum Deviation

±50 dB

ALD VOLUME

2K5

6K3

SENSOR INPUT

0
-10

Power Output

SENSOR
SHORT

RECEIVER SPECIFICATIONS

LT-71

SR-70F
iR Sensor
LT-71™
LightMic
Transmitter

(Optional) HM-70
Handheld Microphone

Receiver Type

Superheterodyne

Receiver Sensitivity

6 µV for 60 dB S/N

Image and Spurious Rejection

> 70 dB

Dimensions (W x D x H)

17.3” x 8.5” x 1.75”

Weight

7 lbs.

TRANSMITTER SPECIFICATIONS
Audio Distortion

Congratulations on your purchase

<1%

The 820iR is a two-channel receiver

Built-in Microphone

Uni-directional Electret
2 AA NiMH Rechargeable

of the 820iR Classroom Ampliﬁca-

ampliﬁer that allows the use of up

Battery Power (1-year warranty)

tion System! This simple, yet power-

to two microphones simultaneously

Inputs

ful technology provides crystal-clear

and up to two additional audio input

sound throughout the classroom,

sources (such as TV, VCR, DVD, CD,

Dimensions (W x D x H)

1.375” x .75” x 4.625”

allowing every child to hear every

MP3, etc.). In addition, LightSPEED

Weight

3.7 oz

word every time.

offers various speaker options that

As the teacher speaks into the
LightMic pendant-style transmitter,
his or her voice is transmitted to the

are included with your system to pro-

Mic Level 3.5 mm
Line Level 3.5 mm

IR SENSOR SPECIFICATIONS

vide optimal sound in rooms of
all shapes and sizes.

Working Range

Up to 1600 square feet
per sensor

820iR and then ampliﬁed through the

The LT-71 LightMic is a wireless, pen-

loudspeaker(s). The standard system

dant-style transmitter. This two-chan-

includes the 820iR infrared receiver/

nel, rechargeable unit is clipped to a

ampliﬁer, LT-71 LightMic™ transmit-

lavaliere cord and worn around the

Dimensions (W x D x H)

4.25” (Diam.) x 2.0” (H)

ter, SR-70 infrared sensor and speaker

neck for teacher use, or it can be used

Weight

4.5 oz

package.

like a standard handheld microphone

Cable

50 ft., Plenum-rated

Mounting

Ceiling clip/Wall bracket

for the students to pass around when
speaking.
1 | 820iR User Manual

820iR User Manual | 18

820iR User Manual

INDIVIDUAL COMPONENTS & OPTIONAL ACCESSORIES
Part Number

Description

RX-820

Infrared receiver/ampliﬁer/mixer w/built-in charger

LT71

LightMic™ rechargeable microphone/transmitter
w/lavaliere cord, batteries and charging cable

HM70

Handheld microphone/transmitter w/batteries and
charging cable

BA-NH1
AC-TCC7

Rechargeable AA battery (Nickel Metal Hydride)
Charging cable for LT-71 and HM-70 microphones

AC-LTCB

Lavaliere cord for LT-71

PS-24V-2.5

Power supply/battery charger for 820iR

SR70F
AC-71CC
SPEAKERS

820iR User Manual

TABLE OF CONTENTS
820iR CLASSROOM AMPLIFICATION SYSTEM
Safety Instructions

Daily Use Instructions

820iR Classroom Ampliﬁcation System

System Components

System Installation

Unpacking Your System

Location of the Receiver/Ampliﬁer

IR Sensor Placement

IR Sensor Installation

Suspended Ceiling Mount

Wall/Solid Ceiling Mount

Speaker Installation

Front Panel Controls

Infrared sensor with cable and wall or ceiling mounting
bracket

Rear Panel Controls

LightMic Controls and Connections

Cradle charger

Initial Setup

Contact LightSPEED at 800.732.8999 for loudspeaker
information

Optional Accessories

Finalizing Receiver/Ampliﬁer

Final Check

System Operation
Turning the System On

9
9

Noise-canceling headset microphone used
with LT-71

Charging the LightMic

System Installation Diagram

BC-TXLT

Wall charger

Input from External Audio Equipment

Output to Personal FM Transmitter

AC-800WB

Wall shelf

Operating the Optional HM-70 Handheld Mic

Charging the HM-70

CA-RCA6

6’ dual RCA audio cable

Tips on Classroom Ampliﬁcation

CA-RCA24

24’ dual RCA audio cable

CA-MMC3535

3.5 mm mono to 3.5 mm mono audio cable

MC-TK250LTM

CA-MMC2535
19 | 820iR User Manual

Audio patch cable (2.5 mm mono to 3.5 mm mono)

Warranty Statement

Troubleshooting Guide

System Speciﬁcations

Individual Components and Optional Accessories

User Notes

820iR User Manual

DAILY USE INSTRUCTIONS

USER NOTES

TURN ON THE 820iR

Record your system serial numbers and
purchase information. This is helpful
when ordering additional components,
accessories, and/or warranty service.

LES 820iR Classroom Amplification System
B VOLUME

A VOLUME
IR

POWER

TV/VCR

CD/DVD

ASSISTIVE LISTENING

WIRELESS MICROPHONE VOLUME

AUDIO INPUT VOLUME

ALD VOLUME

Components

POSITION THE LIGHTMIC

Serial Number

Unplug the LightMic from the

820iR

charging cable and place it around
your neck. Adjust the neck strap so
LT-71

the top of the microphone rests just

Microphones

below your collarbone.
AUDIO INPUT

TV/VCR

250

CD/DVD

400

700

2.06/2.54

SPEAKER OUTPUTS

DC
POWER

CHARGERS

24V
DC

1K
+10

1K4

2K5

6K3

SENSOR INPUT

Sensors

SENSOR
SHORT

-10

LT-71

Speakers

TURN ON THE LIGHTMIC

CHARGE BATTERIES

Turn the microphone ON using the

Plug the LightMic back into the

ON/OFF switch on the side of

charging cable to recharge at the

the LightMic and speak normally.

end of the day.
Purchase Information

OFF

Your School/Organization
District

LT-71

A CH B

Purchase Date
AUDIO INPUT

TV/VCR

250

CD/DVD

2.06/2.54

SPEAKER OUTPUTS

DC
POWER

24V
DC

CHARGERS

400

700

1K
+10

1K4

2K5

6K3

SENSOR INPUT

0
-10

SENSOR
SHORT

Invoice

ii | 820iR User Manual

820iR User Manual | 20

820iR User Manual

USER NOTES

820iR User Manual

SAFETY INSTRUCTIONS
7. Power Sources—This LightSPEED

CAUTION

product should be connected to a
power supply only of the type

RISK OF ELECTRIC SHOCK DO NOT OPEN

described in these operation
instructions or as marked on this

1. Read Instructions—All the safety

and operation instructions should
be read before this LightSPEED
product is operated.
2. Retain Instructions—The safety and

operating instructions should be
kept for future reference.
3. Heed Warning—All warnings on

this LightSPEED product and in
these instructions should be
followed.

LightSPEED product.
8. Power Cord Protection—Power supply

cords should be routed so that
they are not likely to be walked upon
or pinched by items placed upon or
against them.
9. Object and Liquid Entry—Care should

be taken so that objects do not fall
onto and liquids are not spilled into
the inside of this LightSPEED product.
1 0. Damage Requiring Service—This

LightSPEED product should be
serviced only by qualiﬁed service
personnel. The user should not
attempt to service this LightSPEED
product.
11. Prevent Electric Shock—do not use

this polarized plug with an extension
cord, receptacle or other outlet
unless the blades can be fully
inserted to prevent blade exposure.

4. Follow Instructions—All operating

and other instructions should be
followed.
5. Water and Moisture—This Light-

SPEED product should not be used
near water.
6. Heat—This LightSPEED product

should be situated away from heat
sources such as radiators, etc.
21 | 820iR User Manual

820iR User Manual | i

820iR

LightSPEED

Classroom Amplification System

L i g h t S P E E D Te c h n o l o g i e s , I n c .
1 1 5 0 9 S W H e rm a n R d
Tu a l a t i n , O R 9 7 0 6 2
800.732.8999
w w w. l i g h t s p e e d - t e k . c o m

User Manual

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.5
Linearized                      : Yes
Page Count                      : 26
XMP Toolkit                     : XMP toolkit 2.9.1-13, framework 1.6
About                           : uuid:4e241740-3868-11db-9163-000a958f1a42
Create Date                     : 2006:08:08 12:54:38Z
Metadata Date                   : 2006:08:29 11:57:20-07:00
Modify Date                     : 2006:08:29 11:57:20-07:00
Creator Tool                    : Adobe InDesign CS (3.0.1)
Rendition Class                 : proof:pdf
Derived From Instance ID        : a65025a5-285a-11db-b137-9f7805e195cf
Derived From Document ID        : adobe:docid:indd:0a5ed3e7-075a-11db-ba6e-f1d14b153b01
Document ID                     : adobe:docid:indd:a65025a6-285a-11db-b137-9f7805e195cf
Manifest Link Form              : ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream, ReferenceStream
Manifest Reference Instance ID  : uuid:1ddf980c-f67a-11da-af14-000a958f1a42, uuid:62b14ce0-ea33-11d8-93bc-000a958f1a42, uuid:62b14ce0-ea33-11d8-93bc-000a958f1a42, uuid:83502230-2867-11db-9311-ab9fe405a348, uuid:11e7d2c0-9e83-11da-8369-000a958f1a42, uuid:3f75a6e0-4a07-11d9-81da-000a958f1a42, uuid:7013c250-9fda-11da-968d-8d20bde382f3, uuid:ebe5c6ec-4886-11d9-8c47-000a958f1a42, uuid:1f345090-496e-11d9-8d4f-000a958f1a42, uuid:3f75a6e0-4a07-11d9-81da-000a958f1a42, uuid:836ef5c0-5441-11d9-bc40-000a958f1a42, uuid:3c47c91c-5823-11d9-9da1-000a958f1a42, uuid:1f345090-496e-11d9-8d4f-000a958f1a42, uuid:b3bfc123-5047-11d9-be3a-000a958f1a42, uuid:ebe5c6ec-4886-11d9-8c47-000a958f1a42, uuid:11e7d2c0-9e83-11da-8369-000a958f1a42
Manifest Reference Document ID  : uuid:1ddf926b-f67a-11da-af14-000a958f1a42, uuid:62b146ad-ea33-11d8-93bc-000a958f1a42, uuid:62b146ad-ea33-11d8-93bc-000a958f1a42, adobe:docid:photoshop:d4f6a9a0-fb92-11da-bf43-ebe3d5fe6ec9, uuid:4db528a0-bbbc-11d8-8a46-000a958f1a42, uuid:a74b209a-af53-11d8-ab8d-000a958f1a42, adobe:docid:photoshop:afb9fa23-4600-11d9-8312-ab3d009c58fd, uuid:ebe5c11b-4886-11d9-8c47-000a958f1a42, uuid:1f3449cb-496e-11d9-8d4f-000a958f1a42, uuid:a74b209a-af53-11d8-ab8d-000a958f1a42, uuid:42b9bcb8-b670-11d8-ac5b-000a958f1a42, uuid:42b9bcb8-b670-11d8-ac5b-000a958f1a42, uuid:1f3449cb-496e-11d9-8d4f-000a958f1a42, uuid:efcc6f2b-47ce-11d9-8e65-000a958f1a42, uuid:ebe5c11b-4886-11d9-8c47-000a958f1a42, uuid:4db528a0-bbbc-11d8-8a46-000a958f1a42
Format                          : application/pdf
Title                           : 820_MANUAL.indd
Trapped                         : False
Creator                         : Adobe InDesign CS (3.0.1)
Producer                        : Adobe PDF Library 6.0

EXIF Metadata provided by EXIF.tools

Lightspeed Technologies 820Ir Users Manual 820_MANUAL

820iR to the manual a4377bd6-640f-479e-8900-a48a1264ca16

Navigation menu

Versions of this User Manual:

Views

Navigation