The Sennheiser SZI-1015 is a professional infrared (IR) power radiator designed to transmit audio signals wirelessly within an IR listening system, commonly used to provide assistive listening in theaters, courtrooms, lecture halls, and houses of worship. This device functions as the central emitter in the system, converting an audio input signal into modulated infrared light that is broadcast throughout a designated area. It is engineered to deliver clear, secure, and interference-free audio to users wearing compatible IR receivers and headphones or hearing loops, ensuring that individuals with hearing impairments or those requiring language translation can access the audio program privately and without the limitations of radio frequency (RF) transmission, such as licensing or signal bleed-through walls.

The radiator is constructed with multiple high-output IR LEDs arranged to provide wide and even coverage of the listening area. Its design typically includes a wide-angle lens or a multi-directional emitter pattern to flood the space with infrared light, which is then picked up by the receivers. The SZI-1015 operates on a 2-watt power output, offering a balance between coverage area and power consumption, suitable for medium to large-sized rooms. It requires a line-level audio input from a mixer or dedicated IR system processor, which modulates the audio onto a carrier frequency before it is emitted as light. Because infrared light cannot penetrate walls, the signal is completely contained within the room, ensuring privacy and eliminating interference between adjacent spaces.

Installation of the SZI-1015 involves strategic placement to ensure line-of-sight coverage to all potential listener locations, often mounted high on a wall or suspended from a ceiling. It may be used singly or in arrays to cover larger or irregularly shaped areas. The system requires a clean, direct path; obstacles or bright ambient light (especially sunlight) can diminish performance. As a core component of Sennheiser's SI 1015 series of assistive listening products, the SZI-1015 power radiator provides a reliable, high-quality, and universally accessible audio transmission solution that meets accessibility regulations and enhances the experience for all patrons by delivering a discreet and personal audio feed.