Audio Video Glossary

Audio Video Glossary

Sorting Out All Those Terms

It's always frustrating to newcomers and seasoned audio-video enthusiasts alike when you're faced with that array of input and output connectors. It helps to understand which connectors to use and what kind of signals each carries.

Banana Plugs: Use these instead of bare wire at the end of your speaker cables for convenient plug-in speaker (high-level) connections between your A/V receiver's speaker output terminals and your loudspeakers. No improvement in sound quality over bare wire. Virtually all 5-way binding posts on newer speakers and subwoofers accept either single or dual banana plugs, including all of Axiom's speakers. Many A/V receivers' speaker outputs also accept banana plugs if there is enough space. Note: Banana plugs won't work with older speakers' and receivers' plastic spring "push" connectors, which accept only bare wire.

A/V Surround Receiver: An audio/video component with a built-in radio tuner that will receive radio broadcasts on FM or AM, switch different audio and video input sources, and decode Dolby Digital or dts 5.1-channel soundtracks. A/V receivers also contain from five to seven internal amplifiers to amplify the audio signals for delivery to up to seven loudspeakers in a 7.1-channel home theater surround system. All A/V receivers also contain a separate Subwoofer output (the ".1" channel of 5.1 surround) to feed a powered subwoofer for deep bass effects.

Balanced (XLR or Cannon) Connector: A secure 3-wire connector found on all professional and semi-pro sound equipment and on some upscale consumer A/V components (including Axiom subwoofers), enabling very long cable runs without hum pickup or frequency response losses. Must be used with matching balanced connectors on an A/V processor, preamp, or A/V receiver.

Binding Posts, 5-way: A type of speaker cable input and receiver/amplifier output connector that accepts bare speaker wire when you unscrew the top and push the wire through the hole in the post, spade connectors, pins, and single or double banana plugs. Binding posts are only used for High-Level (also called Speaker-Level) connections for amplified audio signals from an A/V receiver's speaker outputs to the speakers.

Blu-ray: A new High Definition video disc standard developed by Sony and other partners that is not compatible with existing DVD players. A rival standard, HD-DVD, developed by Toshiba is currently engaged in a format "war" to decide which will become the High Definition video disc standard. Both are capable of delivering spectacular HD image quality on HD TV displays. Neither type of disc will play on a conventional DVD player, however, a Blu-ray or HD-DVD player will play conventional DVDs with the existing video quality.

Center Channel: In surround sound, a center-channel speaker placed above or below the TV screen, used to anchor the actor's dialogue and sounds occurring in the central part of the video image at the screen. The Center Channel is part of all Dolby Digital 5.1 and dts 5.1 surround formats.

CRT (cathode-ray tube): The familiar heavy glass "picture tube" common to TV displays for over 50 years but now becoming obsolete, replaced by LCD and plasma flat-panel displays as well as DLP and LCD rear-projection and front-projection display. Capable of superb color accuracy and picture detail viewable over a wide angle. Large, heavy, and limited to a maximum of 36 inches diagonal screen size.

Coaxial Cable: Standard 2-conductor shielded cable comprised of an outer woven metal shield (the ground connection) covered with plastic/nylon insulation and further insulated from the inner "hot" or positive wire. Used with RCA male plugs on each end for routing low-level analog audio signals from CD players, DVD players, cassette decks, set-top TV converter boxes, and satellite receivers to A/V receivers and amplifiers. The RCA plugs are often color-coded red for Right channel and white (or black) for Left. Also used for composite-video connection (color-coded yellow) and may be used for digital coaxial audio connection as well. Coaxial audio cable is also used between the A/V receiver's subwoofer output jack (color-coded purple) and the subwoofer line-in connection.

Component Video: Used for both Standard-quality video and High Definition video, it uses three coaxial cables with RCA male plugs color-coded red, green and blue (the three cables may be wrapped together for convenience) to carry analog Standard- or High-Definition video between a set-top satellite or cable-TV box to the A/V receiver and TV display or projector. Most new A/V receivers include component-video inputs and outputs that let you switch between different video sources. Note: Component video cables do NOT carry audio signals. You must connect separate audio cables (either analog or digital) to carry the sound portion of DVD and cable/satellite TV signals. Component-video connections deliver the best picture quality other than HDMI or DVI connectors.

Composite Video: A single video connector that combines all the color and brightness signals into one cable (hence "composite") using a single RCA male connector. Often color-coded yellow, it is the most common type of analog video connection between older VCRs and TVs (except for RF connectors). Use composite video only if your TV, VCR or DVD player lacks S-video or component-video connectors. Composite video will not carry High Def or progressive-scan video signals.

DLP (digital light processing): A TV projection technology developed by Texas Instruments that uses a light source (projector bulb) bounced off the surface of a tiny chip, a digital micro-mirror device (DMD) whose surface is covered by many thousands of tiny, moveable mirrors. Maintenance-free and capable of bright, high-contrast images with good blacks and rich color.

Dolby Digital 5.1 (DD 5.1): Developed by Dolby Labs, this digital surround format delivers up to 5.1 channels of sound. Used throughout the world as the standard soundtrack format for DVDs and High Definition TV as well as for the vast majority of movie soundtracks. All six channels are carried on one digital coaxial cable or optical digital link (Toslink) from the DVD player to the AV receiver. Dolby Digital may also be used for as few as 2 channels, in which case it's DD 2.0. Not all movies are mixed in 5.1 channels.

dts (Digital Theater Sound): A rival digital soundtrack format to Dolby Digital that is an option on some DVDs. Also used in many movie theaters. It is not a required standard for DVD soundtracks but may be included at the option of the producer. Virtually all DVD players and A/V receivers will decode dts or Dolby Digital soundtracks.

Dolby Pro Logic II (DPLII; DPLIIx): An enhanced version of the older Dolby Pro Logic surround system, this format will simulate 5.1-channel playback from a 2-channel stereo source of any kind. The most recent DPLIIx version simulates up to 6.1 or 7.1 channels if one or two back surround speakers are connected.

DVD-Audio: A high-resolution multichannel audio format that uses six or eight shielded RCA coaxial audio cables (sometimes bundled together) to carry analog surround-sound output from a DVD player capable of DVD-Audio playback. Many new A/V receivers have a six- or eight-channel Multichannel analog input set that accepts the multichannel analog audio output of DVD-Audio or SACD players. Don't confuse DVD-Audio with the usual Dolby Digital 5.1-channel or dts digital surround soundtrack of DVDs. DVD-Audio discs are playable only on Universal DVD players.

DVI (Digital Visual Interface): A large computer-like 18-pin connector that carries digital video signals, including High Definition signals, between a set-top HD cable or satellite box or DVD player and an HDTV set. DVI digital video signals are protected by HDCP (High-bandwidth Digital Content Protection) protocol, which prevents you from copying high-quality digital video. DVI is gradually being replaced by smaller HDMI connectors (see below). DVI/HDMI adaptors are available, and many HDTV displays and projectors have both types.

DVR (digital video recorder): An outboard video recorder often supplied by cable TV or satellite TV systems which uses a large-capacity hard drive to record and store video programs, either in Standard Definition or High Definition along with the digital audio surround soundtracks. Often integrated with the cable-TV HD tuner or satellite tuner.

Fiber-Optic (also called Toslink): A thin plastic or glass-fibre cable that carries digital audio signals in an optical format via pulses of light. Uses a small, square plastic male connector on each end. Most modern A/V receivers and DVD players have both Toslink optical digital as well as coaxial digital audio connectors. No difference in sound quality between optical or coaxial digital connections, but optical links are not susceptible to hum or interference.

HD-DVD: A new High Definition videodisc standard developed by Toshiba and other partners that is not compatible with existing DVD players. A rival standard, Blu-ray (see above) developed by Sony is currently engaged in a format "war" to decide which will become the High Definition video disc standard. Both are capable of delivering spectacular HD image quality on HDTV displays. Neither type of disc will play on a conventional DVD player, however, a Blu-ray or HD-DVD player will play conventional DVDs with the existing video quality.

HDMI (High-Definition Multimedia Interface): Much smaller and more convenient than DVI, HDMI is a USB-like digital video connector that carries the same digital video signals as DVI (High Definition and Standard Definition) but with the added advantage of conveying a Dolby Digital surround sound bitstream. Copy protected with HDCP so you can't pirate high-quality digital video. No image superiority of one over the other. May or may not produce a slightly better picture quality than component video.

HDTV (High-Definition TV): The new digital TV standard that features increased horizontal and vertical resolution, a choice of progressive or interlaced scanning, and a widescreen aspect ratio of 16:9 (the ratio of a screen image's width to its height) that conforms to the widescreen visual format of modern movies (older analog TVs have a squarish-looking 4:3 aspect ratio). The most common HD formats are either 720p (720 progressively scanned lines) or 1080i (1080 interlaced scanned lines) or some variation of these. DVDs, although digital, are Standard Definition (480i), which may be displayed as 480p. Some of the latest HD video displays are capable of 1080p clarity, a slight improvement over 720p or 1080i.

Interconnects: Any set of cables or connectors that link A/V equipment of all kinds, however, most commonly the term designates low-level RCA audio and video connectors rather than speaker cables.

Jack: Any female receptacle of an audio or video connector into which the plug, or male connector, is inserted. All connectors have male and female components, RCA plugs and jacks historically being the most common on consumer-grade audio/video equipment. Sometimes the terms jacks and plugs are used interchangeably.

LCD (liquid-crystal display): Color LCD panels used in flat-panel TV and computer displays, and in rear- and front-TV projection sets. Maintenance-free and capable of high resolution. Less than perfect blacks because in most displays light shines through the LCD panels to illuminate the image. May produce grid-like "screen-door effect" if pixels are too coarse, but great improvements have been seen in recent sets.

LCoS (liquid crystal on silicon): Similar technology to liquid-crystal display (LCD) but uses a light source reflected from the LCD panel rather than shining through it. Also known as D-ILA (direct-drive image light amplifier). Capable of performance comparable to DLP and LCD display.

Main Channels: In a 5.1-channel surround system, the front left, center, and right channel speakers. In a stereo system, the front left and right speakers.

Mini-jack, mini-plug: A miniature connector, in mono and stereo versions, commonly found on portable audio equipment for headphone and line-out connections. Rare on A/V gear except for "trigger" outputs and inputs that are used to remotely activate electric screens, separate power amplifiers and subwoofers in elaborate custom home theaters and installations.

Multichannel Analog Input: (see DVD-Audio, above). If your DVD player has the capability of playing back high-resolution DVD-Audio or SACDs, use this six-cable RCA connector set to connect to the analog multichannel input of the A/V receiver. Neither DVD-Audio or SACD hi-res discs have been proven popular.

Phono Jack: Always an RCA female connection on A/V receivers or preamplifiers for the output from a turntable's moving-magnet (MM) or moving-coil (MC) phono cartridge. Still available on up-market receivers and preamps. Don't confuse this with "Phone Plug" (or Jack), which is a larger and sturdier ¼-inch diameter connector used on consumer A/V equipment for larger headphones.

Plasma: A thin-panel video display that uses a huge array of tiny cells filled with ionized gas (plasma) which activates each cell's color phosphor. Viewable over a wide angle and capable of a brilliant image even in brightly lighted rooms. Has good contrast but tends to use more power than other types of video displays.

Receiver: An audio component with a built-in radio tuner that will receive radio broadcasts on FM or AM, switch different audio sources, as well as amplify the audio signals for delivery to loudspeakers. (see A/V Receiver above).

RCA Connector: By far the most common small audio or video connector used on consumer audio/video equipment, with a pin (male) plug and female jack. Uses 2-conductor shielded coaxial cable.

SACD (Super Audio Compact Disc; see DVD-Audio, above): a high-resolution digital multichannel audio standard developed by Sony/Philips that uses DSD (Direct Stream Digital) audio encoding. You'll need a bundled, shielded 6-cable RCA connector set to play back SACD to the A/V receiver as well as an SACD-compatible DVD player. Most inexpensive (less than $150) DVD players will not play SACD or DVD-Audio discs. Only "Universal" DVD players will play these formats as well as conventional DVDs and CDs.

SDTV: Standard-definition digital TV, defined as a 480i signal (480 interlaced scan lines) presented 30 times per second. This is the standard of resolution for all conventional DVDs. Many DVD players may be set to output "progressive scan" 480p signals, which remove the scanning lines producing a smoother film-like picture.

Speaker Cable: Available in various gauges or wire thickness, designated by "AWG" followed by a number e.g., AWG12 is 12-gauge speaker cable. The lower the number, the thicker the cable and the less resistance there is to the passage of amplified audio signals (AWG12 is thick; AWG18 is fairly thin) from you're A/V receiver or amplifier. All speaker cable is 99.9% oxygen-free copper. You'll need one 2-conductor cable for each speaker in your home theater system, except the subwoofer. A 5.1-channel system will require five separate speaker cables plus a single coaxial cable for the subwoofer (see Coaxial, above); a 7.1-channel system, seven cables plus a single coaxial sub cable. Choose the speaker cable gauge by the length of the cable run from the receiver/amplifier to the speaker. For runs up to 20 feet, 14-gauge is fine. Use 12-gauge speaker wire for long runs up to 60 feet. Good generic speaker cable can be purchased in bulk. Speaker cable does not impart musical qualities to the movement of electrons. All copper cables of sufficiently thick gauge sound identical.

Subwoofer: A speaker designed to reproduce only very deep bass frequencies from 100 Hz to 20 Hz or lower. Usually contains its own dedicated amplifier. It is the ".1" channel of Dolby Digital 5.1 and dts surround formats.

Surround Channels: A sound field that is 3-dimensional, intended to envelop the listener, rather than a stereo soundstage mainly in front of the listener. Normally achieve with two discrete surround speakers placed (ideally) to each side of the listening area, used to convey ambient sound effects, special effects and musical enhancement for Dolby Digital 5.1 and dts surround soundtracks. Many Dolby Digital and dts decoders in modern A/V receivers will extract and simulate two additional Back or Rear surround channels for 6.1-channel and 7.1-channel surround setups.

S-video: A small multi-pin connector cable that carries the chrominance (color) and luminance (brightness) video information separately. Not capable of carrying HD video signals but superior in picture clarity to composite video connections. Use this connector for better image quality if your TV, A/V receiver or VCR has S-video inputs and outputs.

Toslink (see fiber-optic, above): A plastic-fibre optical cable for carrying digital audio signals in optical form, as pulses of light, from a DVD player or CD player to an AV receiver. Will carry as many as six separate digital channels of audio for Dolby Digital 5.1 or dts surround soundtracks.

XLR (see Balanced Connector, above).

This list comprises the most common types of audio and video terms you are likely to encounter in setting up your speakers, A/V receiver, subwoofer, TV or HDTV, projector, DVD player, set-top cable box/satellite receiver, VCR or DVR and gaming console.



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