Summary
A small UK maker's installation and maintenance manual for its infrared modulator-radiator, covering interference, placement near windows, commissioning coverage and a maintenance schedule.
Key findings
- States that its system uses Band IV modulation as defined in BS EN 61603-2 and occupies channel H1 (2.3 MHz), "and as such is largely immune to interference from traditional sources such as high efficiency lighting and plasma displays".
- Says the prime coverage is line of sight, but reflections from most hard surfaces give main and reflected coverage when radiators are mounted high; blackout curtains and some red and purple paints affect coverage, so units should be mounted temporarily and tested before final positions are chosen.
- States that "IR radiation does not reflect of most glass surfaces", so radiators should point away from windows.
- Warns against using several modulators in overlapping areas, which causes beat frequencies and poor audio; larger areas use slave radiators.
- Asks commissioning to survey the area with a receiver, normally to cover at least 90% of the used seating, and to mark seats not covered on a room plan displayed so that users can choose covered seats.
- The maintenance schedule recommends monthly receiver listening in the covered area to check that sound is heard without distortion, quarterly checks of each input separately and its received quality, and a yearly engineer visit to check inputs and the field strength at neckloop receivers with a calibrated meter (page 2).
Limits
The maker's claims for its own product, without measurements. The maker's web address now redirects elsewhere, and the copy read is hosted by a reseller. The cover says Revision 2, January 2011, while page footers say Rev 2 Jan 2010; the PDF was created in February 2011. Written before LED lighting was common.
Read the original
www.la-bs.com/Objets/IRMTX750_me.pdf
Cited in
- How many receivers and neckloops does each code require, and how should a loan pool be run?Partly answered
- Where does infrared assistive listening work, and where does it fall short?Partly answered
- Do neckloops give telecoil users good sound from FM, infrared, Wi-Fi and Auracast receivers?Not reliable yet
- How can a venue check that its assistive listening works for listeners, day to day?Partly answered
Cite this source
Current Thinking Ltd. IRMTX750 Infra Red Modulator & Radiator: Installation and Maintenance Manual (Revision 2). Current Thinking Ltd (Infra~Hear range); copy hosted by a French audiovisual reseller. January 2011. https://www.la-bs.com/Objets/IRMTX750_me.pdf (accessed 13 October 2026).
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