The SI 30 is a small-to-medium area master transmitter that can be switched from 2.3 MHz to 2.8 MHz or used simultaneously for two channel/stereo operation. Utilizing these higher-than-usual subcarrier frequencies, this system avoids the interference generated by electronically-ballasted fluorescent lights. With the capability of covering 750 square feet, the SI 30 can be used with up to three SZI 30 slave emitters for increased coverage. This cost-effective system is ideal for conference rooms, Houses of Worship, courtrooms and similar type rooms up to 3,000 sq. ft.