Glossary
The manufacturers in the custom home theatre industry have a unique set of terms, acronyms and abbreviations that are used in specifying and describing high-end audio/visual products. Whether you’re upgrading an existing home movie theatre or just starting the process of learning about home theatre installations, home automation, or lighting control systems, it’s to your benefit to know and understand this terminology.
A.
Active: Usually refers to a self powered loudspeaker or un-amplified, but electronically manipulated, crossover network.
Amplifier: A component found in both individual and distributed audio systems that increases the gain or output level of an audio signal. Converts low voltage to high voltage.
Aspect Ratio: The ratio of image width to image height. Conventional television screens typically have a 4:3 aspect ratio. Custom home theatre widescreen televisions and HDTVs have an approximate aspect ratio of 16:9. When widescreen movies are displayed on 4:3 televisions, the image must be letterboxed to fit the space. Original film frames usually carry an aspect ratio that is 2.35 times as wide as it is high, in widescreen or 16:9 format. This means letterboxing may be even be required on some widescreen TVs.
Amplifier: A component found in both individual and distributed audio systems that increases the gain or output level of an audio signal. Converts low voltage to high voltage.
Aspect Ratio: The ratio of image width to image height. Conventional television screens typically have a 4:3 aspect ratio. Custom home theatre widescreen televisions and HDTVs have an approximate aspect ratio of 16:9. When widescreen movies are displayed on 4:3 televisions, the image must be letterboxed to fit the space. Original film frames usually carry an aspect ratio that is 2.35 times as wide as it is high, in widescreen or 16:9 format. This means letterboxing may be even be required on some widescreen TVs.
B.
Bass: Low frequency audio signals (below approximately 200 Hz.).
Bipolar Speakers: Speakers that consist of two driver arrays facing opposite directions, both firing in phase or in time with one another to create a larger soundstage for home theatre audio systems.
Bipolar Speakers: Speakers that consist of two driver arrays facing opposite directions, both firing in phase or in time with one another to create a larger soundstage for home theatre audio systems.
C.
Cathode Ray Tube (CRT): This is the type of picture tube used in a traditional television. The picture was created by firing a stream of electrons at a series of phosphors wile tracing lines on a screen to create the image.
CD-R: Recordable Compact Disc.
CD-RW: Rewritable Compact Disc.
Center Channel Speaker: This is the speaker in a home theatre system that is typically used for the dialogue channel. It is usually placed directly above or below the television or display device, so that the sound of voices stay anchored to the screen. As much as 85% of recorded information in a movie will be steered to the dialog or centre channel.
Channel: It is the pathway, usually an assigned frequency, that is used to carry information wirelessly from one place or product to another in home video distribution or distributed audio systems.
Component Video: A special type of connection that keeps the red, green and blue components of the colour or chrominance signal, separate through the entire video circuit path.
Composite Video: A video signal in which the black and white or luminance and chrominance (colour), stay combined through the entire home video circuit path. This is the lowest performing video connection and will not pass a high definition signal typically generated by source components in custom home theatre systems.
Contrast: The difference between the brightest and darkest parts of an image. The number of different shades of brightness (or gray) that can be distinguished between extreme black and extreme white. There are many different ways to measure contrast in a picture, so there is very little standardization or commonality with specifications Crossover A component of distributed audio systems, usually found in a loudspeaker, that divides an audio signal into two or more ranges of frequency and distributes them to specific components.
CD-R: Recordable Compact Disc.
CD-RW: Rewritable Compact Disc.
Center Channel Speaker: This is the speaker in a home theatre system that is typically used for the dialogue channel. It is usually placed directly above or below the television or display device, so that the sound of voices stay anchored to the screen. As much as 85% of recorded information in a movie will be steered to the dialog or centre channel.
Channel: It is the pathway, usually an assigned frequency, that is used to carry information wirelessly from one place or product to another in home video distribution or distributed audio systems.
Component Video: A special type of connection that keeps the red, green and blue components of the colour or chrominance signal, separate through the entire video circuit path.
Composite Video: A video signal in which the black and white or luminance and chrominance (colour), stay combined through the entire home video circuit path. This is the lowest performing video connection and will not pass a high definition signal typically generated by source components in custom home theatre systems.
Contrast: The difference between the brightest and darkest parts of an image. The number of different shades of brightness (or gray) that can be distinguished between extreme black and extreme white. There are many different ways to measure contrast in a picture, so there is very little standardization or commonality with specifications Crossover A component of distributed audio systems, usually found in a loudspeaker, that divides an audio signal into two or more ranges of frequency and distributes them to specific components.
D.
Diaphragm: A term used to describe that part of a driver (aka. Speaker component) that moves air, which produces sound. It usually has the shape of a cone or dome.
Digital: Refers to the series of numbers (1 and 0) in a sequence that depict an analog frequency. The process by which frequencies are encoded and decoded to remove noise, maximize dynamic range and improve overall performance.
Diffusion: In fixed and distributed audio systems, the scattering or dispersion of sound waves.
Dipole: Speakers with drivers facing opposite directions, operating out of phase or out of time with each other, to create a larger and deeper sound field. Ideal for changing the dynamics of home theatre acoustics by making smaller spaces seem larger.
Direct-Stream Digital: A format for encoding high-resolution audio signals.
Dispersion: The spreading of sound over a wide area.
Dolby Digital: An encode/decode process that surround sound and home theatre audio systems use. A special algorithm used to process movie soundtracks into 5.1 channels of audio information: Left Front, Center, Right Front, Left Surround, Right Surround and .1 of the bandwidth allocated for a subwoofer channel.
Dome: A type of shape used to describe speaker drivers, typically the tweeters. Concave domes are usually referred to as "inverted domes."
Driver: The active element of a loudspeaker in home theatre audio systems, that create air movement to produce sound. The primary parts of a driver are the cone (or dome), which moves the air, voice coil and the magnet.
DTS (Digital Theatre Systems): A digital sound recording format that was originally developed for theatrical film soundtracks, starting with Jurassic Park. It is similar to Dolby Digital as a process, but is based on a different algorithm. Digitally compresses up to 5.1 discrete channels of audio (left front, centre, right front, left surround, right surround and subwoofer) into a single bit stream. Five channels are full-range; the .1 channel is typically used for a subwoofer. Competing format is Dolby Digital (see above).
DTV (Digital Television): Umbrella term used for the system that will eventually replace our NTSC system in 2009. A way of broadcasting SDTV, EDTV and HDTV signals digitally. This removes a significant amount of noise and improves the picture and sound.
D-VHS: A recorder that records digital signals onto magnetic tape and has greater capacity than a standard VHS.
DVD (Digital Video Disc): A video reproduction format, utilizing a dual laser read and write-system. Storage capacity ranges from 4.5 Gb (single layer, single-sided) to 17 GB storage capacity. DVD is currently the most common format utilized by the best home theatre systems for source material of movies.
DVD-A (DVD Audio): Digital Versatile Disc-Audio. Enhanced audio format utilized by home theatre audio systems with up to six channels of high-resolution audio encoded onto a DVD.
DVD-R: One-time only recordable DVD format.
DVD-RW: Re-writable DVD format.
DVD-RAM: A recordable DVD format that is capable of being written and erased more than 100,000 times.
Digital: Refers to the series of numbers (1 and 0) in a sequence that depict an analog frequency. The process by which frequencies are encoded and decoded to remove noise, maximize dynamic range and improve overall performance.
Diffusion: In fixed and distributed audio systems, the scattering or dispersion of sound waves.
Dipole: Speakers with drivers facing opposite directions, operating out of phase or out of time with each other, to create a larger and deeper sound field. Ideal for changing the dynamics of home theatre acoustics by making smaller spaces seem larger.
Direct-Stream Digital: A format for encoding high-resolution audio signals.
Dispersion: The spreading of sound over a wide area.
Dolby Digital: An encode/decode process that surround sound and home theatre audio systems use. A special algorithm used to process movie soundtracks into 5.1 channels of audio information: Left Front, Center, Right Front, Left Surround, Right Surround and .1 of the bandwidth allocated for a subwoofer channel.
Dome: A type of shape used to describe speaker drivers, typically the tweeters. Concave domes are usually referred to as "inverted domes."
Driver: The active element of a loudspeaker in home theatre audio systems, that create air movement to produce sound. The primary parts of a driver are the cone (or dome), which moves the air, voice coil and the magnet.
DTS (Digital Theatre Systems): A digital sound recording format that was originally developed for theatrical film soundtracks, starting with Jurassic Park. It is similar to Dolby Digital as a process, but is based on a different algorithm. Digitally compresses up to 5.1 discrete channels of audio (left front, centre, right front, left surround, right surround and subwoofer) into a single bit stream. Five channels are full-range; the .1 channel is typically used for a subwoofer. Competing format is Dolby Digital (see above).
DTV (Digital Television): Umbrella term used for the system that will eventually replace our NTSC system in 2009. A way of broadcasting SDTV, EDTV and HDTV signals digitally. This removes a significant amount of noise and improves the picture and sound.
D-VHS: A recorder that records digital signals onto magnetic tape and has greater capacity than a standard VHS.
DVD (Digital Video Disc): A video reproduction format, utilizing a dual laser read and write-system. Storage capacity ranges from 4.5 Gb (single layer, single-sided) to 17 GB storage capacity. DVD is currently the most common format utilized by the best home theatre systems for source material of movies.
DVD-A (DVD Audio): Digital Versatile Disc-Audio. Enhanced audio format utilized by home theatre audio systems with up to six channels of high-resolution audio encoded onto a DVD.
DVD-R: One-time only recordable DVD format.
DVD-RW: Re-writable DVD format.
DVD-RAM: A recordable DVD format that is capable of being written and erased more than 100,000 times.
E.
EDTV (Extended Definition Television): The term used to describe any home theatre projector or Digital Television (DTV) capable of displaying image quality of 480p or higher.
Equalization: The process of changing the frequency of an electrical signal to alter the acoustical output.
Equalizer: An electronic component that alters the frequency balance of an audio signal.
Equalization: The process of changing the frequency of an electrical signal to alter the acoustical output.
Equalizer: An electronic component that alters the frequency balance of an audio signal.
F.
Feedback: Some or all of the output of a home theatre audio system component (such as an amplifier) taken back to the input. This may be accidental (such as feedback from a speaker) or intentional, to reduce distortion.
FireWire: Also known as IEEE 1394. This is a high quality two-way connection between electronics.
Frequency Response: A measure of what frequencies can be reproduced by a given component and how accurately they are reproduced. The best home theater systems have a high frequency response rating.
Full-Range Speaker: A speaker designed to reproduce the full range of human hearing response (20 Hz to 20 kHz) of audio frequencies.
FireWire: Also known as IEEE 1394. This is a high quality two-way connection between electronics.
Frequency Response: A measure of what frequencies can be reproduced by a given component and how accurately they are reproduced. The best home theater systems have a high frequency response rating.
Full-Range Speaker: A speaker designed to reproduce the full range of human hearing response (20 Hz to 20 kHz) of audio frequencies.
G.
Graphic Equalizer: A device used to electronically manipulate the volume of specific frequencies.
H.
HDTV (High-Definition Television): A term used to describe the highest level of picture performance. A television capable of producing high-resolution, digital images (at least twice the resolution of the existing TV standard). HDTVs are widescreen (16:9) in format and produce an image with 720 progressive (1366 x 768) or 1080 (up to 1920 x 1080) interlaced or progressive scan lines. All high-end home video distribution systems incorporate HDTV technology.
Home Theatre: recreates the cinematic movie theatre experience within the home. Custom home theatres, like those developed by members of HTSA, are professionally designed and installed in the home and come complete with electronics, home video distribution systems, distributed audio systems, home theatre furnishings and often, intelligent lighting controls and custom accessories such as home theatre curtains and luxury home theatre chairs.
Home Theatre in a Box: A term used to describe a very poor substitute for good quality home theatre systems. Usually refers to 5 speakers, a subwoofer and some form of amplification sold as a package from a single manufacturer. See Home Theatre above.
Home Theatre: recreates the cinematic movie theatre experience within the home. Custom home theatres, like those developed by members of HTSA, are professionally designed and installed in the home and come complete with electronics, home video distribution systems, distributed audio systems, home theatre furnishings and often, intelligent lighting controls and custom accessories such as home theatre curtains and luxury home theatre chairs.
Home Theatre in a Box: A term used to describe a very poor substitute for good quality home theatre systems. Usually refers to 5 speakers, a subwoofer and some form of amplification sold as a package from a single manufacturer. See Home Theatre above.
I.
Integrated Amplifier: A combination of a preamplifier and an amplifier in a single chassis.
Interconnects Refers: to the actual connection type or any cable or wire running between two pieces of electronic equipment.
Interlace: A television image technology referring to the process of alternating scan lines to create a complete image. In CRT televisions, tracing the scan lines in two fields (odd and even) to produce a complete image 30 times per second. The fields are aligned and timed so that the human eye views them as one image. Interlace scanning can be prone to motion based artifacts.
Inverted Dome: A type of speaker-driver shape (usually used for tweeters).
Interconnects Refers: to the actual connection type or any cable or wire running between two pieces of electronic equipment.
Interlace: A television image technology referring to the process of alternating scan lines to create a complete image. In CRT televisions, tracing the scan lines in two fields (odd and even) to produce a complete image 30 times per second. The fields are aligned and timed so that the human eye views them as one image. Interlace scanning can be prone to motion based artifacts.
Inverted Dome: A type of speaker-driver shape (usually used for tweeters).
J.
K.
Keystone: A form of video image distortion, usually associated with front projection TVs, in which the image is shaped like a trapezoid rather than a rectangle. There is usually an adjustment available on better quality projectors kHz Kilohertz or one thousand Hz.
L.
LCD (Liquid Crystal Display): A television monitor technology that sandwiches a layer of liquid crystal between two transparent displays. A light source behind the panel (fluorescent or LED) transmits the image through the crystals. Each crystal is controlled individually and uses TFTs as electronic shutters to control light output. LCD technology is commonly used in some of the best home theatre systems.
Letterbox: A conversion format to fit wide-aspect-ratio movies. When an image is shrunk to fit the screen without distorting the original widescreen (16:9) format, black horizontal bars are used to fill in the missing area, leaving blank space on the top and bottom. All custom home theatres come equipped with Letterbox technology.
Luminance: The black and white (Y) portion of a video signal. The luminance channel carries the detail of a video signal.
Letterbox: A conversion format to fit wide-aspect-ratio movies. When an image is shrunk to fit the screen without distorting the original widescreen (16:9) format, black horizontal bars are used to fill in the missing area, leaving blank space on the top and bottom. All custom home theatres come equipped with Letterbox technology.
Luminance: The black and white (Y) portion of a video signal. The luminance channel carries the detail of a video signal.
M.
Media Server: New type of storage and playback device utilized by the best home theatre systems that is designed to eliminate having to keep and organize all of your content such as music, photos, videos etc., instead storing them electronically on an accessible hard drive.
MHz: Megahertz, or 1 million Hz.
Midbass: An area of the low frequency range, usually represented from approximately 80 to 500 Hz.
Midrange: The middle of the audio frequency range. Usually represented from approximately 500Hz to 2500 Hz.
Mono: A single channel of sound. The lowest form of audio recreation. Eliminates the ability to create a sense of space or depth.
Multi-Room/Multi-Zone: An electronic component of distributed audio systems that feature the capability to distribute multiple sources in different rooms of a home, often simultaneously. For example, the same music can be played in the kitchen, home movie theatre and a bedroom at the same time. More advanced systems allow you to distribute different streams of information to different rooms.
MHz: Megahertz, or 1 million Hz.
Midbass: An area of the low frequency range, usually represented from approximately 80 to 500 Hz.
Midrange: The middle of the audio frequency range. Usually represented from approximately 500Hz to 2500 Hz.
Mono: A single channel of sound. The lowest form of audio recreation. Eliminates the ability to create a sense of space or depth.
Multi-Room/Multi-Zone: An electronic component of distributed audio systems that feature the capability to distribute multiple sources in different rooms of a home, often simultaneously. For example, the same music can be played in the kitchen, home movie theatre and a bedroom at the same time. More advanced systems allow you to distribute different streams of information to different rooms.
N.
O.
P.
Passive Speaker: A speaker that does not have an internal or built-in amplifier.
Pixel: The smallest element of viewable data in a video image.
Plasma: Flat-panel display technology that turns a gas into a liquid, which in turn excites phosphor elements. Plasma technology is commonly used in some of the best home theatre systems, as each pixel element can be individually controlled.
Preamplifier: A control and switching component designed to manipulate analog frequencies at low voltage (typically around 2.0 volts).
Progressive Scanning: A format for displaying a video image in which each frame of a sequence is scanned complete, from top to bottom, not in separate fields. This helps eliminate motion artifacts.
Projection System: A way of utilizing a high output lamp to shine a smaller image onto a much larger surface. All the best home theatre projectors incorporate this technology.
Pixel: The smallest element of viewable data in a video image.
Plasma: Flat-panel display technology that turns a gas into a liquid, which in turn excites phosphor elements. Plasma technology is commonly used in some of the best home theatre systems, as each pixel element can be individually controlled.
Preamplifier: A control and switching component designed to manipulate analog frequencies at low voltage (typically around 2.0 volts).
Progressive Scanning: A format for displaying a video image in which each frame of a sequence is scanned complete, from top to bottom, not in separate fields. This helps eliminate motion artifacts.
Projection System: A way of utilizing a high output lamp to shine a smaller image onto a much larger surface. All the best home theatre projectors incorporate this technology.
Q.
R.
Receiver: Typically a tuner combined with an amplifier and/or loudspeaker. Custom home theatre Audio/Video receivers also combine additional functionality and typically have a digital sound processor built in such as Dolby Digital or DTS.
RGB (Red, Green, Blue): These three primary colours combine together to make every colour in a range viewable on a display device.
Ribbon Speaker: A loudspeaker that consists of a thin, corrugated, metallic ribbon suspended in a magnetic field.
RGB (Red, Green, Blue): These three primary colours combine together to make every colour in a range viewable on a display device.
Ribbon Speaker: A loudspeaker that consists of a thin, corrugated, metallic ribbon suspended in a magnetic field.
S.
SACD (Super Audio CD): An older enhanced, high-resolution format of CD. SACDs are specially encoded and require an SACD player and six channels of digital audio for the best home theatre audio playback performance.
Scan Lines: The lines drawn by an electron gun in a CRT television to make up the picture.
SDTV (Standard Definition Television): A format of Digital Television (DTV). SDTVs have a lower resolution signal than High Definition TV (HDTV). Generally, 480i (interlaced) is considered the accepted quality for SDTV, while the best home theatre systems utilize 1080i (interlaced) or 1080p (progressive) technology.
Selection Device: The hardware used to present the appropriate image to the appropriate eye and to block the unwanted image. For 3D movie the selection device is usually eyewear used in conjunction with a device at the projector, like a polarizing device.
Soft-Dome Tweeter: A tweeter that uses a fabric or plastic dome.
Soundstage: A term used to describe the location of the performers as recreated by the front set of loudspeakers. Correct speaker placement will create the appropriate width, depth and height of a soundstage. Strategic placement of home theatre acoustic panels will further enhance the optimal listening area.
Subwoofer: A speaker designed to reproduce low bass frequencies; usually those below about 80 Hz. Subwoofers are used for both music systems and home theatre audio systems.
Surround Sound: A specific system of speakers designed to surround a listening area in fully dimensional, life-like sound. A typical custom home theatre utilizes a 5.1-channel or 7.1 channel surround sound system consisting of five to seven speakers plus one to four subwoofers (the .1 channel). The five to seven speakers are: front stage, centre stage, side stage and rear stage speakers.
S-VHS (Super VHS): An older, tape based video recorder format utilizing a higher bandwidth to store and playback more resolution and picture information. It utilized a proprietary video connection method.
S-Video (Separated Video): A special connection that separates the luminance (black and white information) from the Chrominance (colour information) to eliminate crosstalk and improve picture quality. Luminance is usually 80% of the picture.
Scan Lines: The lines drawn by an electron gun in a CRT television to make up the picture.
SDTV (Standard Definition Television): A format of Digital Television (DTV). SDTVs have a lower resolution signal than High Definition TV (HDTV). Generally, 480i (interlaced) is considered the accepted quality for SDTV, while the best home theatre systems utilize 1080i (interlaced) or 1080p (progressive) technology.
Selection Device: The hardware used to present the appropriate image to the appropriate eye and to block the unwanted image. For 3D movie the selection device is usually eyewear used in conjunction with a device at the projector, like a polarizing device.
Soft-Dome Tweeter: A tweeter that uses a fabric or plastic dome.
Soundstage: A term used to describe the location of the performers as recreated by the front set of loudspeakers. Correct speaker placement will create the appropriate width, depth and height of a soundstage. Strategic placement of home theatre acoustic panels will further enhance the optimal listening area.
Subwoofer: A speaker designed to reproduce low bass frequencies; usually those below about 80 Hz. Subwoofers are used for both music systems and home theatre audio systems.
Surround Sound: A specific system of speakers designed to surround a listening area in fully dimensional, life-like sound. A typical custom home theatre utilizes a 5.1-channel or 7.1 channel surround sound system consisting of five to seven speakers plus one to four subwoofers (the .1 channel). The five to seven speakers are: front stage, centre stage, side stage and rear stage speakers.
S-VHS (Super VHS): An older, tape based video recorder format utilizing a higher bandwidth to store and playback more resolution and picture information. It utilized a proprietary video connection method.
S-Video (Separated Video): A special connection that separates the luminance (black and white information) from the Chrominance (colour information) to eliminate crosstalk and improve picture quality. Luminance is usually 80% of the picture.
T.
3:2 Pulldown: A process by which frames are repeated in order to convert the original 24 frames of film to the 60 frames of video required to show the picture on a TV. THX An encode/decode process for optimizing theatre sound reproduction into 7.4 channels of information. Considered to be the optimum performance standard for home theatre installations.
Tweeter: A speaker component or driver designed to reproduce high frequencies.
Tweeter: A speaker component or driver designed to reproduce high frequencies.
U.
Universal Remote: A single remote that can control several different components of a home movie theatre simultaneously.
V.
W.
Wall Mount: A bracket used to affix a flat panel television to a vertical wall.
Watt: A unit of power or energy.
Woofer: A speaker component or driver designed to reproduce low frequencies.
Watt: A unit of power or energy.
Woofer: A speaker component or driver designed to reproduce low frequencies.
X.
Y.
Z.
Zone: An area in a house designated for an entertainment usage (such as distributed audio or home video distribution). A home can be divided into multiple zones, all of which can access the same or different sources simultaneously.
Audio / Visual Solutions
Network & Security
Automation
Energy Management
