The Sennheiser SI 30 is a professional two-channel infrared transmitter designed to broadcast audio wirelessly via infrared light within enclosed spaces such as conference rooms, courtrooms, houses of worship, and theaters for assistive listening or silent disco applications. This unit is capable of operating in two independent modes: it can transmit two completely separate mono audio channels for multilingual interpretation, or it can combine the inputs to transmit a stereo audio signal. The infrared technology ensures secure, license-free operation contained within the room, as the signals cannot pass through walls, making it ideal for confidential proceedings or situations where RF wireless is impractical or prohibited. The transmitter features robust construction for rack-mount installation and is designed for continuous, reliable operation in fixed installations.

The SI 30 accepts standard line-level audio inputs via XLR or 6.3mm jack connectors and modulates them onto infrared carrier frequencies. It includes comprehensive status indicators for power, audio presence, and IR transmission levels, allowing for easy monitoring. The unit drives a network of infrared radiators, which are placed around the room to flood the space with invisible IR light carrying the audio signal. Listeners use compatible infrared receivers with headphones to pick up the signal. A key feature is its switchability between dual-channel and stereo modes, providing flexibility for different applications—delivering two language channels for an international conference or a high-fidelity stereo feed for a musical performance.

For system integrators, the Sennheiser SI 30 represents a reliable and secure solution for wireless audio distribution where privacy and interference-free operation are paramount. Its ability to handle two discrete channels supports sophisticated multilingual environments, while its straightforward setup and operation make it accessible for daily use. By providing clear, wireless audio directly to personal receivers, it enhances accessibility for the hard of hearing and enables private listening without disturbing others, making it an essential component in modern, inclusive AV design for public and professional spaces.