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The LA-141 Expansion Radiator (Pat. 9,712,246) from Listen Technologies expands on the functionality and coverage area of the LT-84 Infrared Transmitter/Radiator combo system, giving users and clients an uninterrupted, high-performance listening experience.

Up to four (4) LA-141 Expansion Radiators can be added to the LT-84 system, providing additional coverage up to 2,787 m2 (30,000 ft2) with LR-4200-IR/LR-5200-IR receivers or 697 m2 (7,500 ft2) with LR-42/LR-44 receivers in single-channel mode. A single CAT-5e cable provides both power and signal to the radiators, and the included mounting hardware and single-cable design make installation and setup a breeze.


One (1) LA-141 ListenIR Expansion Radiator
One (1) 25 ft. (7.6 m) CAT-5e Cable
One (1) LA-344 Flexible Mounting Hardware
One (1) Quick Start Guide


  • The only product of its kind that provides complete, gap-less coverage in small- to mid-size spaces
  • Up to four radiators can be added to the LT-84 system providing additional coverage up to 2,787 m2 (30,000 ft2)
  • Single-cable CAT-5e provides power and audio signal for ease of setup
  • Simple installation with the included mounting hardware
Configurations & Architectural Specs


LA-141 ListenIR Expansion Radiator (For LT-84 only)

Architectural Specs

The IR Expansion Radiator shall be capable of receiving four (4) mono carrier frequencies of; 2.3, 2.8, 3.3 and 3.8 MHz over a proprietary RJ-45 Expansion Link. The device shall be connected via a single CAT-5e cable (100 ft. (30 m) maximum) providing power and RF signal.  The Expansion Radiator coverage area shall be up to 30,000 ft² (2787 m²) with LR-4200-IR/LR-5200-IR receivers or 7,500 ft² (697 m²) with LR-42/LR-44 receivers in single channel mode. The device shall deactivate the IR emitting LEDs after 15 minutes if no audio is present. When connected to a Trans-Radiator the device shall have a system audio performance of 60 dB SNR or better, THD of less than 2% and a frequency response of 63 Hz to 15 kHz, +/- 3db.  The Expansion Radiator shall have an Expansion in and out RJ-45 connection allowing an additional Expansion Radiator to be connected (two per daisy chain, two daisy chains per Trans-Radiator) for up to four (4) Expansion Radiators in a system. The Expansion radiator shall provide delay compensation via two (2) rotary four (4) position switches for up to two (2) audio channels. The LA-141 is specified.

CAD file(s)

Product Specifications
Specification LA-141


System Distortion < 2% (THD) System Specification (wireless end-to-end with LR-44)
System Signal to Noise Ratio (A-Weighted) > 60 dB (SNR) System Specification (wireless end-to-end with LR-44)
System Frequency Response 63 Hz - 15 kHz (+/- 3 dB) System Specification (wireless end-to-end with LR-44)


Indicator Lights On/Off Switch Two (2) position switch - Indicator Lights OFF, Indicator Lights ON
Delay Compensation Four (4) position rotary switch setting (0, 1, 2, 3)


RJ-45 Amber LED Solid Amber indicates carrier is present and IR is being transmitted
RJ-45 Green LED Solid Green indicates power is applied to unit


Carrier Frequencies 2.3 MHz, 2.8 MHz, 3.3 MHz, 3.8 MHz
Number of Channels Two (2) channels
Power Save Mode Carrier will shut off when no audio is present for 15 minutes on both channels to preserve radiator life.
Expansion Link Output One (1) RJ-45 connector - Provides RF Signal and Power to one additional LA-141.CAT-5e cable 24 AWG, 100 ft. (30 m) maximum cable length, two (2) LA-141s per daisy chain (total daisy chain cannot extend beyond two expansion radiators)
Expansion Link Input One (1) RJ-45 connector - Receives RF Signal and Power from LT-84


Coverage Area 30,000 ft² (2787 m²) single channel with LR-4200-IR/LR-5200-IR receivers or 7,500 ft² (697 m²) single channel with LR-42/LR-44 receivers
IR Emitter Power 1.49 W


Power Supply 12 VDC, Provided via LT-84 Expansion Link Output RJ-45s
Current Draw 600 mA per LA-141, maximum of two (2) LA-141s daisy chained with CAT-5e cable 24 AWG 100 ft. (30 m) to each LT-84 Expansion Link Output


Color Black with White Silk Screening
Shipping Weight 3.0 lbs. (1.4 kg)
Mounting Can be mounted on a wall, ceiling, or table with provided hardware (screws and hollow wall anchors not provided). Optional LA-347 Wall Box Mounting Plate is available for mounting to a standard single gang electrical box.
Dimensions (H x W x D) 1.5 x 10.7 x 4.1 in. (3.81 x 27.2 x 10.5 cm)
Unit Weight 0.6 lbs. (0.3 kg)


Temperature - Operation 14 °F (-10 °C) to +104 °F (40 °C)
Temperature - Storage -4 °F (-20 °C) to +122 °F (50 °C)
Relative Humidity 0 to 95% relative humidity, non-condensing


Standards FCC Part 15, ICS-03, CE, UL, CUL, C-Tick, CCC, PSE, KC, GS, RoHS, WEEE
Used With
Q What is the warranty of the LA-141?
A The LA-141 has a 3-year warranty. Listen warranty
Q What is the purpose of the delay compensation switches?
A This 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 switches, it is not necessary to cut all of your cables to the same length - your shorter runs can use shorter cables, keeping your installation clean (and cost-effective).
Q What is the coverage area provided by the LA-141?
A 7,500 ft² (697 m²) line-of-sight in single channel mode, using a Listen LR-44 or LR-42 receiver.
Q Does the number of channels (carriers) affect the coverage area?
A Yes, for one (1) channel (carrier), the line-of-sight coverage area is 30,000 ft² (2787 m²) and for two (2) channels (carriers), the line-of-sight coverage area is 15,000 ft² (1394 m²) with LR-4200-IR/LR-5200-IR receivers.
Q How many Expansion Radiators (LA-141) can you use on a system?
A Yes, for one (1) channel (carrier), the line-of-sight coverage area is 30,000 ft² (2787 m²) and for two (2) channels (carriers), the line-of-sight coverage area is 15,000 ft² (1394 m²) with LR-4200-IR/LR-5200-IR receivers.
Q How do I connect multiple Expansion Radiators (LA-141)?
A A maximum of two (2) LA-141s can be connected to each Expansion Link output RJ-45 on the LT-84 with a maximum daisy chained CAT-5e cable length of 100 ft. (30.5 m). CAT-5e cable must be at least 24 AWG!
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