Home Cinema Terms
Home cinema gets more complex every day, so do the terms used to explain certain requirements, specifications and equipment. Here is a list of common and not so common abbreviations and home cinema terms.
A/V Recievers - Combination of Stereo amplifier and radio tuner, the central component of a home theatre
ATSC - Advanced Television Systems Committee. Government-directed committee that developed our digital television transmission system.
Aspect ratio - The ratio of image width to image height. Common motion-picture ratios are 1.85:1 and 2.35:1. Television screens are usually 1.33:1 (also known as 4:3), which is similar to the Academy standard for films in the '50s. HDTV is 1.78:1, or 16:9. When widescreen movies (films with aspect ratios wider than 1.33:1) are displayed on 1.33:1 televisions, the image must be letterboxed, anamorphically squeezed, or panned-and-scanned to fit the screen.
CD-R - Recordable Compact Disc
CD-RW - Rewritable Compact Disc
Coaxial - An audio or video cable with a single center pin that acts as the hot lead and an outer shield that acts as a ground.
Coloration - Any change in the character of sound that reduces naturalness.
Dolby B - A noise-reduction system that increases the level of high frequencies during recording and decreases them during playback.
Dolby surround sound - An encoding system that digitally compresses up to 5.1 discrete channels of audio (left front, center, right front, left surround, right surround, and LFE) into a single bitstream, which can be recorded onto a DVD, HDTV broadcast, or other form of digital media. When RF-modulated, it was included on some laser discs, which requires an RF-demodulator before the signal can be decoded. Five channels are full-range; the .1 channel is a band-limited LFE track. A Dolby Digital processor (found in most new receivers, preamps, and some DVD players) can decode this signal back into the 5.1 separate channels. Most films since 1992's Batman Returns have been recorded in a 5.1 digital format, though a number of films before that had 6-channel analog tracks that have been remastered into 5.1.
Dolby Pro Logic - An enhancement of the Dolby Surround decoding process. Pro Logic decoders derive left, center, right, and a mono surround channel from two-channel Dolby Surround–encoded material via matrix techniques.
DVD - Officially known as the Digital Video Disc.
DTS - Digital Theater Systems
DTV - Digital Television
DVDA - Digital Versatile Disc-Audio. Enhanced audio format with up to six channels of high-resolution
DSP - Digital Signal Proc Digital Versatile Disc-Audio. Enhanced audio format with up to six channels of high-resolutionessing. Manipulating an audio signal digitally to create various possible effects at the output. Often refers to artificially generated surround effects derived from and applied to two-channel sources.
DTS ES - An enhanced version of the 5.1 DTS system. Like Dolby's Surround EX, a sixth channel is added
Equalizer - A component designed to alter the frequency balance of an audio signal.
Frequency Response - A measure of what frequencies can be reproduced and how accurately they are reproduced. A measurement of 20 to 20,000 Hz ± 3dB means those frequencies between 20 and 20,000 Hz can be reproduced no more than 3 dB above or below a reference frequency level.
Full-Range speaker - A speaker designed to reproduce the full range (20 Hz to 20 kHz) of audio frequencies.
HDTV - High-Definition Television.
Home Theater in a Box - A complete home theater system in one box . Consists of five or more speakers, a subwoofer, and a receiver. May also include a DVD player
LCD - Liquid Crystal Display. A display that consists of two polarizing transparent panels and a liquid crystal surface sandwiched in between. Voltage is applied to certain areas, causing the crystal to turn dark. A light source behind the panel transmits through transparent crystals and is mostly blocked by dark crystals.
Midrange speaker - The middle of the audio frequency range. Also used as a term for loudspeaker drivers designed to reproduce this range.
MP3 - MPEG-1 Audio Layer-3. Compression scheme used to transfer audio files via the Internet and store in portable players and digital audio servers.
NTSC - National Television Standards Committee
Piezo - A type of speaker driver that creates sound when a quartz crystal receives electrical energy.
Plasma: Flat-panel display technology that ignites small pockets of gas to light phosphors
Projection System - Display that projects image onto a screen.
RCA Jacks - Receptacles for coaxial cables carrying line-level audio signals. Also called phono-type connectors.
Rear-Projection Television - Display that projects an image on the backside of a screen material, usually after having been reflected off of a mirror.
Ribbon Speaker - A loudspeaker that consists of a thin, corrugated, metallic ribbon suspended in a magnetic field
SACD - Super Audio CD. Enhanced audio format with up to six channels of high-resolution audio encoded using DSD. Requires an SACD player.
SDTV - Standard Definition Television
Signal-to-Noise Ratio - A comparison of the signal level relative to the noise level. Larger numbers are better.
Sub woofer - A speaker designed to reproduce very low bass frequencies, usually those below about 80 Hz.
Transducer - A device that turns electrical energy into mechanical energy, usually used to shake the seating in a theater
Tweeter - A speaker driver designed to reproduce high frequencies; usually those over approximately 5,000 to 10,000 Hz.
VHS - Vertical Helical Scan . Widely used method of recording audio and video electrical signals onto magnetic tape.
WMA - Windows Media Audio.
Watt - A unit of power or energy. One horsepower is equal to 745.7 watts.
Woofer - A speaker driver designed to reproduce low frequencies.
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