Infrared Technology – NSL

Infrared Technology

Communicate your message without sacrificing security or sound quality. Infrared listening technology from Williams Sound ensures peace of mind, every time. From courtrooms to conferences, from retrofit to new construction, Williams Sound has complete, turnkey solutions to meet your facility’s needs for hearing assistance, simultaneous interpretation, audio description or secure listening services.


These wireless systems utilize infrared light to carry audio to individuals needing auditory assistance or language interpretation to overcome background noise, reverberation and distance from the sound source. Individuals use personal infrared receivers anywhere within the coverage area to hear crystal-clear sound directly from the sound source.

Transmitters and Emitters

Small-area Infrared Transmitter


Its sleek, compact footprint is ideal as an assistive listening system for small areas or for private TV listening in such areas as small conference rooms, hospital rooms, assisted living facilities, medical treatment centers and jury deliberation rooms. The T1 is so energy efficient it can be powered from a standard USB port on a TV. Provides a coverage area of up to 1,300 square feet.

Medium-area Infrared Transmitter


Commercial-grade, sleek, compact and ideal for assistive listening and language interpretation in commercial spaces such as conference rooms, assisted living facilities, small cinema/theaters, classrooms and courtrooms. The IR T2 infrared transmitter offers up to 18,000 square feet of coverage. With a significantly wider coverage pattern and more power, there is no need for the additional expense of secondary units.

Two-channel, Infrared Modulator


Each microprocessor-controlled MOD 232 modulator handles two audio channels. Daisy-chain two MOD 232s together for four-channel operation.


Large-area, Multi-channel Infrared Emitter


The powerful WIR TX9 DC emitter produces a wide-angle infrared signal that concentrates infrared energy efficiently in the listening area. Operating on the 2.3-3.8 MHz bandwidth, the WIR TX9 DC is less susceptible to radio and lighting interference. Each WIR TX9 DC emitter can cover up to 30,000 square feet in single-channel operation. Coverage area can be easily increased by daisy-chaining additional WIR TX9 DC emitters. A wall/ceiling omnidirectional mount is included, and stand kits are available for portable operation.



Large-area, Multi-channel Infrared Transmitter


The powerful four-channel WIR TX90 DC transmitter combines modulator and emitter technology into a single operating unit, which reduces operating costs, eliminates the need for rack space and eases set-up. The WIR TX90 DC features application pre-set controls for music, voice or hearing assistance applications – no guesswork required for audio configuration. Everything you need for installation is in the box.


The powerful emitter produces a wide-angle infrared signal that concentrates IR energy efficiently in the listening area. Operating on the 2.3-3.8 MHz bandwidth, the emitter is less susceptible to radio and lighting interference. Each emitter can cover up to 30,000 square feet in single-channel operation.

The coverage area can be easily increased by daisy chaining additional WIR TX9 DC emitters.



Four-channel Selectable, Infrared Receiver


Compatible with transmitters operating on the 2.3/2.8/3.3/3.8 MHz bandwidth. Considered best in class, the highly receptive WIR RX22-4N offers a range of up to 30,000 square feet in single-channel mode when used with a Williams Sound WIR TX925 or WIR TX90 infrared system. Body-pack design features convenient channel selector and easy on/off volume control. Can be used with mono or stereo headphones, earphones or a neckloop (lanyard included). Uses AA alkaline or rechargeable batteries for up to 60 hours of operation. 5-year warranty.

Two-channel Infrared Receiver


Designed for use with a transmitter operating on 2.3/2.8 MHz, in single-channel or stereo. Range of up to 3,063 square feet in single-channel mode when used with a Williams Sound WIR TX925 or WIR TX90 DC infrared system. Lightweight (weighing only 2 oz.), one-piece design is comfortable, easy-to-clean and rechargeable (use CHG 518 five-bay charger). 5-year warranty.

How it works

1) Input to an infrared system can come from a microphone, sound system or another audio source. Here, the presenter speaks to participants using an existing microphone. The microphone is fed into a mixer.


2) This audio from the microphone is then fed to the infrared modulator, which prepares the signal for infrared transmission. The processed signal is then fed to the emitter, which produces the invisible infrared light and radiates it into the room.


3) Infrared receivers convert the infrared light back to audio. Participants requiring hearing assistance each use an infrared receiver to listen to the presenter.


· Easy to install

· Secure – transmission confined within opaque walls

· Resistant to RF interference

· Accommodates multiple adjacent rooms without spillover

· Integrates easily with existing sound systems

· Legal for use in any country

· Up to four simultaneous channels available

· Global Disability Legislation Compliant

· 5-year warranty

Request a demo

Unit 2, 180 Montgomerie Rd
Airport Oaks
Auckland 2022

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