Low-frequency effects

The low-frequency effects (LFE) channel is the name of an audio track specifically intended for deep, low-pitched sounds ranging from 3-120 Hz. This track is normally sent to a speaker that is specially designed for low-pitched sounds called the subwoofer. While LFE channels originated in Dolby Stereo 70 mm film prints, they became commonplace in the 1990s and 2000s in home theater systems used to reproduce film soundtracks for DVDs and Blu-ray discs.