Simple Explanation

A sound system with six audio channels: five for speakers around the listener, and one for bass effects/subwoofer (the “.1”).

Concise Technical Definition

A digital audio format with five full-range (20 Hz–20 kHz) channels—left, right, center, left surround, right surround—and one low-frequency effects (LFE) channel (20 Hz–120 Hz).

Layman-Friendly Analogy

Like being in the middle of a movie theater, with sound coming from all directions—and a subwoofer for the deep rumbles.

Industry Usage Summary

A multichannel format developed by the Moving Picture Experts Group, commonly used in film, DVD, Blu-Ray, and HDTV. “5.1” stands for five full-range channels and one subwoofer (LFE) channel, often used for bass or effects.

Engineering Shortcut

5.1 = 5 full-bandwidth (20 Hz–20kHz) + 1 LFE (20–120Hz) channel

Full Technical Explanation

The 5.1 surround sound format was developed by the Moving Picture Experts Group for digital soundtracks in film, laserdiscs, DVD, Blu-Ray, and HDTV. The “5.1” name (coined by Tom Holman of THX fame) designates five discrete, full-bandwidth (20 Hz–20 kHz) channels—left, right, center, left surround, and right surround—plus one low-frequency effects (LFE) channel (20 Hz–120 Hz), typically handled by a subwoofer. This setup creates a more immersive, spatial listening experience.