The Performance Stationary IR System is designed for installations that require mounting of the transmitter (rack mount) and radiator. The system includes four (4) Listen stetho receivers, and a convenient storage station, and an ADA compliance signage kit for venues to demonstrate ADA compliance. The system can cover up to 20,000 ft²  (1,858 m²). Listen’s IR systems are designed for applications that require the audio signal to be isolated for security or other reasons, such as assistive listening, soundfield, language interpretation, live theater, houses of worship, courtrooms, secure rooms, and for auditory description. Custom systems available. Grey or white radiator options available. 


One (1) LT-82 Stationary IR Transmitter
One (1) LA-326 Universal Rack Mounting Kit
Two (2) LA-140 Stationary IR Radiator
Four (4) LR-42 IR Stethoscope 4-Channel Receiver
Four (4) LA-363 High Capacity AAA Alkaline Batteries (2)
One (1) LA-351 8-Unit IR Storage Station
One (1) LA-304 Assistive Listening Notification Signage Kit


  • Accommodates up to four (4) listeners – great for applications to accommodate a small group
  • Outstanding coverage – 20,000 ft² (1,858 m²)
  • Secure wireless communication – ideal for applications where isolation of the signal is important
  • Up to four (4) channels mono or stereo – no need to sacrifice multiple channels to achieve stereo transmissions
  • Easy to specify, install and use
  • Outstanding performance ensures crystal clear sound for listeners
Configurations & Architectural Specs


LS-81-01-GY Performance Stationary IR System -Grey (North America)*
LS-81-02-GY Performance Stationary IR System -Grey (Asia, UK)*
LS-81-03-GY Performance Stationary IR System -Grey (Euro)*
LS-81-04-GY Performance Stationary IR System -Grey (Australia)*
LS-81-01-WH Performance Stationary IR System -White (North America)*
LS-81-02-WH Performance Stationary IR System -White (Asia, UK)*
LS-81-03-WH Performance Stationary IR System -White (Euro)*
LS-81-04-WH Performance Stationary IR System -White (Australia)*

*01, 02, 03, and 04 designation refers to international plug type (type B, G, C, and I) for the power supply. 

Architectural Specs

The LS-81 Performance Stationary IR System shall use infrared (IR) light to transmit audio from IR emitting radiators to portable IR receivers. The system shall use IR modulating frequencies above 2.0 MHz. The system transmitter shall have a timer that shuts off the carriers after 30 minutes when no audio is present at the transmitter. Channel selection shall be capable of being locked. The system shall be capable of transmitting on four (4) carriers and each of the four (4) carriers shall be capable of transmitting a mono or stereo signal. The system shall have a frequency response of 100 to 15 KHz (+/-3 dB), less than 2% distortion and shall have signal to ratio of greater than 60 dB. A single emitting radiator shall have a transmitting area of no less than 10,000 ft²  (929 m²) (one carrier) or greater for each radiator specified. The radiator shall be powered via CAT-5 cabling and the RF from the transmitter shall be carried by 50 ohm coaxial cable. The LS-81 is specified.

Product Specifications


Shipping Weight27.0 lbs. (2.3 kg)
QCan the LT-82 be operated on 230 VAC?
AYes, the LT-82 has a universal power supply that can be used anywhere in the world.
QIs there any performance degradation in stereo mode?
AYes, stereo operation raises the noise floor slightly.
QCan I operate some channels in mono and others in stereo?
QHow many carriers does the LT-82 Stationary IR Transmitter produce?
QHow many carriers can be produced simultaneously in a room?
AFour. You will need one LT-82 Stationary IR Transmitter per carrier.
QHow are radiators connected to the LT-82?
AThe carrier (signal) is connected using coax cable; power is connected using standard CAT-5 cabling.
QHow is power delivered to the radiator?
APower is delivered with CAT-5 cables (connected between the radiator and either the LT-82 transmitter or the LA-205 power supply).
QHow many radiators can be powered from the LT-82 or LA-205 power supply?
QHow much coverage is provided with the LA-140 radiator?
A40,000 ft² (3716 m²) single channel with LR-4200-IR/LR-5200-IR receivers or 10,000 ft² (929 m²) single channel with LR-42/LR-44 receivers
QDoes the number of carriers affect the coverage?
AYes, for two sources (carriers), the total coverage is half. For four carriers, the coverage per carrier is one-fourth.
QWhat is the purpose of the delay compensation switch?
AThis switch allows you to set up delay timing in a multi-radiator system so that each radiator receives the carrier at exactly the same time. This prevents signal dropouts that can be caused by out-of-phase signals (multi-path). With Listen’s delay compensation switch, it is not necessary to cut all of your coaxial cables to the same length - your shorter runs can use shorter cables, keeping your installation clean (and cost-effective).
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