The XLi Series of power amplifiers from Crown represents a new era in affordable, quality power amplification. All four models in the series are powerful, rugged and reliable. They are suited for musicians, DJs, and entertainers as well as houses of worship, discos, and pubs. User selectable input sensitivity: 0.775V and 1.4V. Efficient forced-air cooling prevents excessive thermal buildup.Two level controls, power switch, power LED, and six LEDs which indicate signal presence, clip and fault for each channel. Protection against shorts, no-load, on/off thumps and radio-frequency interference.