Home Theater Glossary: L
LAN: Local area network. A computer network that links two or more computers together within a limited range. You can add a computer LAN to your home theater infrastructure, resulting in a whole-home computing system that can make use of your home theater.
LCD: 1. (noun) An acronym for liquid crystal display. An LCD is a flat-panel TV display with pixels consisting of liquid crystal molecules held between two sets of transparent electrodes. 2. (noun) The technology used in LCD panels, computer monitors, LCD projectors in a front-projection system, and many other devices.
LCoS: An acronym for Liquid Crystal on Silicon. LCoS is a newer type of projection system that reflects light off of the liquid crystals. This results in a significantly brighter image than an LCD projection system.
letterboxing: An approach used to display widescreen (16:9) content (such as movies) on a standard (4:3) television. Letterboxing maintains the original aspect ratio by displaying horizontal black bars at the top and bottom of the screen.
LNB: An acronym for Low Noise Blocker. The LNB is a horn-shaped device connected to the front of the parabola of a satellite dish, used to block extraneous signals.
long runs: A type of cable that makes up the infrastructure of a whole-home audio and video network. Long-run cable is designed to minimize signal loss due to interference. The longer the signal has to travel over cable, the more likely that signal will be audibly degraded.
lossless: A category of codecs in which all the music information in the audio file is preserved when the file is compressed and stored on a computer, with no loss and very large file sizes. Some lossless codecs include Windows Media Lossless, Apple Lossless, PCM, and Free Lossless Audio Codec (FLAC).
lossy: A category of codecs in which part of the music information in the audio file is discarded when the file is compressed, resulting in smaller file sizes. In many cases, the loss of these bits of audio isn't noticeable. Some lossy codecs include MP3, WMA, and AAC.
Low Frequency Effect channel: An audio channel encoded in the soundtrack of a movie or other surround-sound source that provides the low-frequency bass sounds that you hear from the subwoofer. The LFE channel is the ".1" in 5.1 and other surround-sound formats.
LP: Long playing. A phonograph record, often referred to as vinyl, that plays at 33-1/3 revolutions per minute.
luminance: The brightness portion of the two-component video signal that runs through a video cable (the other component is chrominance).