Audio/Video Glossary Words for thought!
Last update: January 3rd, 2008

HowToHookItUp.com Home Theater and Electronics Glossary

All of the terms used on our site can usually be found here (along with many others). If we're missing something, let us know and drop an email to help@howtohookitup.com.

You can use the letters below to jump around the glossary.

#


16:9: Proportions of a high definition display. It is also written as 1.78:1, which is the same as saying the width is 1.78 times the height. Theatrical films are shot in widescreen, often using aspect ratios of 1.78:1, 1.85:1, and 2.35:1. The closer to 1.78:1 the ratio on a DVD is the more the picture will fill the screen (with either no or very small black bars at the top and bottom).

4:3: Proportions of a regular, non-widescreen display. Also written as 1.33. This has been the standard ratio for TVs and films until Hollywood created 16:9 to differentiate film from television (in an effort to boost theater attendance)

480/720/1080: These numbers represent possible TV or display resolutions. For example, a standard definition TV has a resolution of 480i. Some TVs are marketed at 480p, or EDTV (Enhanced Definition); they can play high definition but only at the lower resolution of 480p. True high definition begins with 720i. The "i" and "p" stand for interlaced and progressive. Progressive gives more lines of resolution on the screen and is therefore a shaper picture. HD resolution continues up to 1080i and 1080p for the best possible picture. Very little media exists today to utilize 1080p resolution, while most is 720p or 1080i.



A


Amplifier: Amps are usually found integrated into modern day receivers. They serve to add more energy to a signal. You can add external amplifiers to further add more energy to the sound signal. This is useful for sound systems with very low wattages or when you are using older technology that requires an amplifer.

Anamorphic Format: Using an anamorphic lens, film could be captured on 35mm reels and fill the entire available space for the picture. Before anamorphic came about (pre-1950s), the picture did not fill each frame of film completely on the vertical axis. With anamorphic lenses, the picture is "squeezed" horizontally so that it fills the frame both horizontally and vertically. The frame is never edited vertically; the anamorphic lense only manipulates the frame horizontally. Projectors required a special anamorphic lense to display the film correctly. Today, anamorphic is the standard film format.

Anamorphic Widescreen: Unlike the anamorphic format, anamorphic widescreen is a DVD format that allows an anamorphic film to take advantage of not just vertical space but extra horizontal space as well. If it didn't, you would have bars on the left and right of your picture as well as top and bottom. When played on a standard 4:3 television, anamorphic films can be more efficientlly cropped down to size to fit the screen, most often utilizing black bars on the top and bottom (letterboxing). The biggest advantage to anamorphic widescreen is that more lines of resolution (or scan lines) can be used on the display. A 1.78:1 film will use close to 100% of your TV's resolution, while a 2.35:1 ratio would result in around 90%, but still much more than if it was not anamorphic.

Aspect Ratio: The technical definition for aspect ratio is an image's displayed width divided by its displayed height, such as 1.85:1 or 2.39:1. Standard definition televisions are 4:3 (1.33:1) and high definition uses 16:9 (1.78:1). When shopping for DVDs, take note of the aspect ratio indicated on the back of the packaging. For a high definition TV, 1.85:1 will utilize more of your display than a 2.39:1 film (smaller bars on top and bottom).

ATSC: A television transmittal standard developed by the Advanced Television Systems Committee. ATSC is an all-digital format set to replace today's current format, NTSC, by February, 2009. After that point, you will need a TV with an ATSC "tuner" to pick up the signal you get from a standard cable line. Analog antennas will no longer function. Alternatively, you will be able to use a high definition antenna on an HD TV to pick up terrestial HD broadcasts.

Audio/Video Receiver: An A/V receiver is a typical surround sound receiver of today. The audio/video portion of it makes mention to its ability to not only accept and ouput sound signals but video as well. A common use of this is called Video Switching, which allows you to connect multiple video sources to a receiver (with accompanying audio sources) and then switch between each one through just one video connection to a display. This simplifies the use of cables and remotes so all you have to do is power on your components and then use your receiver's remote control.



B


Bandwidth: Measured in hertz, bandwidth is, technically, the difference between upper and lower cutoff frequencies of a signal. Its a little different when we talk about computer networking but it all boils down to the same thing: How much data can you cram into a signal? The lower the bandwidth, the lower the quality of whatever it is you're sending in the signal. Digital signals have very high bandwidth, like HDMI, which allows for high definition video and full surround sound.

Black Level: The level of brightness at the darkest part of a screen is known as black level. Televisions have different degrees of black levels which result in either very dark black color or lighter, more "lit" black color. The idea of true black color is the absence of light, but televisions and computer monitors can't accomplish this. The black level indicates just how close to true black a display can create.

Blu-Ray Disc: A high definition media format similar to DVD. Using a blue optical laser with a shorter wavelength than the standard red DVD laser, Blu-Ray can pack much more data into a smaller space. A Blu-Ray disc can hold 25GB of data as compared to 7.5GB of a DVD. A dual-layer Blu-Ray disc can hold up to 50GB. You must use a Blu-Ray player and high definition TV to make use of Blue-Ray discs. Note that Blue-Ray is in competition with HD DVD, a competing format. Certain film companies have sided with one or the other, while some produce discs for both formats. Consider this when purchasing one technology or the other.

Brightness: The visual perception of a given luminance. Brightness is how much light is applied to a display to increase its luminance (the amount of light passing through a given area).

C

Cathode Ray Tube (CRT): Your classic television or computer monitor. Using an evacuated glass tube, an electron gun, and a fluorescent screen, you're able to get a quality image with a great black level. LCDs, plasmas, and projection TVs have always tried to compete with CRT picture quality. They're getting close, and future technology not yet available has the capability to even improve on what the CRT is capable of. The problem with CRTs is, of course, their immense size and weight. Few manufacturers still produce CRT televisions (and monitors) in lieu of dropping flat panel and other TV technology prices.

Channel: When talking about sound, speakers, or receivers, a channel represents a digital pathway across circuit boards that information is passed through. Its basically the highways that data rides across within your electronic devices. For a receiver, you would want one with what's known as discrete channels. This means all your speakers and subwoofer have indepedent channels, allowing for true surround sound.

Chrominance: The signal used to transfer color information separately from the luma signal. This is a method of transferring a video signal with the ability to adjust the bandwidth for separate channels of color (red green and blue).

Coaxial Cable: Coaxial is what connects to your TV, cable or satellite box. Its a single cable with a thin "pin" extruding from the end. The kind you use in your house is labelled RG-6. The previous format used was RG-59, but it is not suitable for long distances and doesn't have the same shielding as RG-6. Shielding around the cable prevents interference and leakage. Using RG-59 would result in "snow" and other distortion in your TV signal.

Color Temperature: The technical definition is complex and probably won't give you an idea of what color temperature has to do with real-world applications, so I'll give it to you straight: color temperature is quite literally how warm or cold the color on a display appears to be. If you've ever played around with the settings of a high definition TV, you've almost certainly seen a Color Temperature option. It might be listed with numbers (like 6500k) or by words (Cool, Warm, etc.). A TV should be set closer to 6500k (measured in Kelvins) (or "Warmer"/"Warmest"). Different TVs require difference settings of the color temperature to reproduce an image as it was designed to be seen, so experimentation is necessary on a unique basis for every display.

Component: A piece of equipment. For example, a surround sound receiver is a component. So is a speaker, a subwoofer, and a television - all components. Any electronic device can be labelled as a component.

Component Video: An analog video signal used for televisions that is split into three separate video components. Even though the cables are usually red, green, and blue, that's not what is actually going on inside the cables. Instead, two channels include color and one includes luma. The RGB (red, green, blue) type of component cable is used primarily for computers and comes in the form of a VGA cable. It is still a component video cable (just as s-video is a component video connection since it utilizes two channels). We've just come to know the familiar three-piece component cable as the definitive component video. It represents the highest quality in analog video and transmit high definition up to 1080p. A digital connection like HDMI or DVI would provide improved video quality.

Composite Audio: Composite cables usually come in threes: red, white, and yellow. The red and white composite cables represent stereo audio (left and right) channels. It is a basic, analog audio connection commonly used for connecting the audio of DVD players, VCRs, game systems, cable boxes, and other devices to your TV.

Composite Video: Unlike component video, composite combines the luminance channel and two channels of chrominance into one analog cable. This results in lower bandwidth and hence lower image quality. Composite video represents the worst quality video you can get next to using a plain old coaxial cable (which should only be used with a VCR).

Contrast: As far as TV and video is considered, look at Contrast Ratio below.

Contrast Ratio: The difference between the brightest and darkest points on a screen. When purchasing a television, you'll probably notice talk of a contrast ratio. This can be seen as ratios like 800:1, 1000:1, 10,000:1... The problem with that is that most manufacturers pick and choose how they determine the contrast ratios of their TVs. For one company, 800:1 could be the same as 10,000:1 on another manufacturer's TV. For the most part, contrast ratio is marketing-speak, but generally, the higher the better. You want a good contrast ratio to deliver deeper, darker black on your TV. If your contrast ratio is low, black will appear more gray. This results in lighter, more washed out images with less detail in darker scenes. LCD, plasma, and projection TVs have always suffered from an inferior contrast ratio to that of CRT televisions. Recently, the technology has improved, and black levels are significantly better.

D

Decibel: Used commonly for measuring volume. Decibels represents the magnitude of a physical quantity relative to a reference level. Its not just used for sound (light intensity is one alternative). A decibel is more simply the pressure of the sound you're listening to. The higher the decibel, the higher the pressure. Not all sound is essentially louder at higher decibels, however, because there are many frequencies of sound. The human ear reacts differently to each frequency, so sometimes a sound at very high decibel won't actually sound as loud as expected.

Digital Coaxial Cable: A cable that looks the same as an RCA cable but is capable of transferring digital audio. This means you can get 5.1 (or greater) surround sound from a DVD player, cable box, or other device through a digital coaxial cable. You can use a regular composite cable, but over certain distances or because of different shielding, it might not work. Either way, as with most cables, the real difference is in the actual connection on the device it is connecting to and the technology in the device itself. Most cables have the exact same wire running through them but might use different shielding or connector tips.

DLP: A trademarked name by Texas Instruments, Digital Light Processing represents a newer technology used in both projection television (DLP projection) and video projectors. It was developed all the way back in 1987 but only made it into consumer products in the last few years. DLP supports a slimmer profile for a projection TV and enhances picture quality. DLP sets also have a remarkable black level as compared to competing technologies.

Dolby Digital: Dolby Laboratories is the company behind a series of audio compression all labelled Dolby Digital. By itself, Dolby Digital, also known as AC-3, is the most common version. It supports up to six discrete channels (five speakers and a subwoofer). It is the standard in surround sound compression technologies, meaning most DVDs will have a Dolby Digital sound track capable of up to 5.1 surround sound.

Dolby Digital EX: Note: replaces the old Pro-Logic format. When you can't get true surround sound (no digital connections, or the content you're playing doesn't support it), there is Dolby Digital EX. It will mix the stereo sound to add in a center and rear channel. It is also used to add in a 6th or 7th channel (for up to 7.1) concerning actual surround sound. It does not create a discrete 6th channel, however, so it isn't true 6.1 or 7.1 surround sound.

Dolby Digital Plus: Building on the original Dolby Digital, Plus enables up to 13.1 surround and increased bitrate (audio quality). It is also backwards compatible with regular Dolby Digital soundtracks and has improved coding technology to prevent compression artifacts.

Dolby Digital Live: Real-time encoding for games and other sorts of interactive media. It actively converts audio signals on a computer or game console into 5.1 Doly Digital surround sound. It is transported over an S/PDIF (fiber optic) cable.

Dolby TrueHD: HD DVD requires mandatory support on all HD DVD discs for Dolby TrueHD. This method of compression allows the highest quality, lossless audio up to 14.1 channels.

Dot Crawl: A reference to a visual defect afflicting color analog video transmitted over composite video. It looks like a checkboard pattern animated over the screen. It can also result in hard to read text or loss of detail. The main problem here is that composite video has such a low bandwidth that the chrominance and luminance of the signal end up crossing frequencies.

DSP: Digital Signal Processing. Used for converting analog signals to digital through the use of a converter.

DTS: The competitor to Dolby Digital, Digital Theater System is another codec (compression/decompression technique) used in film and on DVD. It clams to produce a more lifelike sound with a better dynamic range than Dolby Digital. It is not as common as Dolby Digital, but DTS can be found on many DVDs. It is often selectable within a DVD's audio options, and sometimes it is the main audio track for a DVD.

DTS ES: The ES is for Extended Surround, allowing for up to 7.1 speaker configurations. It supports a discrete center-surround channel and plays the two rear-center channels in mono sound.

DTS NEO:6: NEO:6 converts stereo sound into 5.1 or 6.1 channel surround sound.

DTV: Two possible meanings: either DirectTV (satellite television provider) or Digital Television. In the case of digital television, it is a telecommunication system for broadcasting via digital signals. On February 17th, 2009, all television broadcasts will be digital, resulting higher quality picture and sound. This requires a digital TV or a digital-to-analog converter box (the government will soon offer $40 coupons to purchase one). If your TV is only a few years old or if it is a high definition TV, you don't have to worry about it.

DVD: Known as Digital Versatile Disc as well as Digital Video Disc, DVD is known for being the main storage media for movies. Many computer games and software applications now come on DVD as well. The movies you buy are on dual layer DVD-ROM discs. They can not be written to and hold up to 8.54 GB of data. You may have also heard of DVD-R and DVD+R. These are two writeable formats of DVD. The difference is the plus and minus. To us, there is no difference, but some players and recorders support one, the other, or both formats. The same goes for DVD-RW and DVD+RW, which are re-writeable DVDs. All of these discs can hold up to 4.7 GB on a single layer while dual layer discs can hold 8.54 GB. There is a third format known as DVD-RAM. RAM discs are also rewriteable and only supported by a select number of players and recorders.

DVD-Audio: There are two discs related to DVD-Audio. One means any DVD disc formatted with just audio. This could be a disc you burn on the computer with music. The other is DVD Audio, a special kind of DVD sold to be played in DVD players with support for DVD Audio. It plays in 5.1 surround sound, unlike regular CDs or DVDs with music on them. The tracks are specially mastered in 5.1, higfh quality surround sound. The alternative to DVD Audio is Super Audio CD, which also requires special players for 5.1 playback.

DVD-RAM: See DVD.

DVI Cable: Digital Visual Interface. DVI is designed to support uncompressed digital video data and high definition. Many high definition TVs use DVI and most new computers and video cards use DVI to connect to a monitor.

E

EDTV: Enhanced definition refers to a high definition TV or display that downgrades a high definition signal from 1080 or 720 lines of resolution to 480. A standard television plays at 480i, meaning interlaced, while EDTV plays at 480p, or progressive. The difference is very slight, but it allows for a lower priced TV that supports high definition. True high definition content is played at a minimum of 720i.




F

Fiber Optic Cable: A digital cable using light to transmit data. It allows for uncompressed audio and video data to be transmitted. For home use, fiber optic is only used for audio connections, in particular, 5.1 surround sound.

Firefox: The main competitor to Internet Explorer, Firefox is an open-source web browser developed by the Mozilla Foundation. It is free to use and possibly even more secure than Internet Explorer.

G

Google: The world's best and most famous search engine. If you can't find it on Google, you're not looking hard enough. If you need to know something, format a search as you would expect to find it on a webpage, not as a question. If I was trying to hook u my home theater, I'd try "how to hook up home theater" or "home theater setup".



H

HD DVD: High Definition DVD. One of the competing next-gen formats for the storage of high definition media on an optical disc. HD DVD was created by the same consortium that brought you DVD; the DVD Forum. It is a collective of manufacturers and other special interest groups who define and create standards (like DVD and HD DVD). You might hear a lot about Toshiba and HD DVD, and that's because Toshiba leads the DVD Forum and manufacturers HD DVD players, but no single company is responsible for the development of HD DVD.

HDCP: Another acronym. This time, it means High-Bandwidth Digital Content Protection. Quite basically, it is a protection mechanism implemented on newer high definition devices (TVs, HD DVD players, Blu-Ray players, computer software, DVRs, etc.) to prevent digital data from being intercepted during transmission. In other words, its an attempt to stop consumers from copying, recording, or otherwise stealing high definition content. The only real problem with HDCP is that it wants you using digital connections only. If you try using component video on an HDCP device, your resolution will probably be downconverted to non-high def resolution (if it lets you use component video at all). S-video and composite video probably won't even be found on these devices. If they are, its most likely a TV, and they server a different purpose.

HDMI Cable: High-Definition Multimedia Interface. The newest in all-digital connections, HDMI allows for the transmittal of both audio and video through the same cable. The video can be up to 1080p high definition as well as any assortment of surround sound audio. It is the best possible audio and video connection available for home theater today. Note that there are different revisions of HDMI, the latest being 1.3. Each revision supports more and more features and sometimes they are not backwards compatible. Make sure your devices match up, but more importantly, make sure your HDMI cable is the correct revision.

High Definition: The new era of digital television: HD. Better resolution, better sound, and more interactivity. High definition content ranges from 720i to 1080p resolution. Anything less is either Enhanced Definition or Standard Definition. In order to view high definition TV, you need an HD TV and a source of high definition, such as cable service, satellite service, or an HD over the air antenna. Some local stations are broadcast in high definition and can be picked up freely with an antenna. Cable and satellite both require a box and the upgraded service to receive high definition content.

High Definition TV/HD Built-In: Both these terms represent a TV that is not only capable of picking up a high definition signal but also has an HD tuner built into the TV. This allows you to pick up high definition with an HD antenna or through some source outside of cable and satellite. If your TV is not built-in, you will always need a cable box or satellite receiver to watch any high definition content.

High Definition Monitor: Unlike a High Definition TV, a monitor does not have a high definition tuner built into it. You will always require a satellite receiver or cable box (or similar device) to receive high definition broadcasts. External tuners can costs well over a hundred dollars if you were trying to receive over the air broadcasts with an HD antenna.

HTIB (Home Theater In a Box): You can actually buy a home theater system in one convenient box. Its a cheap, quick way to get yourself into home theater. Prices range from around $50 to well over $500 for HTIB's. They usually include 5 speakers, a subwoofer, and a receiver. Some come with DVD players (most often build into the receiver), 6 or even 7 speakers, and speaker wire. Most systems are not on the same level as if you were to purchase components separately. A quality home theater system won't be found in a box for under $200. If you want to compete with the movie theaters, plan to spend around $1,500 for a decent system built piece by piece (not including the TV). The sky really is the limit with home theater.



I

Interlaced: Interlacing is done to improve image quality by removing the flicker inbetween frames. It is used to prevent consuming extra bandwidth in the video signal. The principle is that every other frame includes opposite lines of resolution. That means that one frame will contain half the lines of resolution in an image (every other line) and the next frame will have the missing lines. This method makes the image look fluid and smooth to the human eye, but if slowed down, you could see that you're actually looking at half a frame at a time. Most standard definition TVs use interlacing while LCD, DLP, and plasma displays cannot be interlaced due to their design. They use progressive scan instead.




L

Letterbox: We've all seen it: black bars on top and bottom of your TV. This usually happens when watching a DVD. It doesn't matter if your TV is high definition, widescreen, or square; widescreen DVDs will always have black bars (unless the TV can zoom in on the image). This is purposely done to preserve the aspect ratio of whatever you're watching (in most cases, it will be a film's original aspect ratio). If the picture were allowed to fill the entire screen, it would be distorted vertically. So why don't they just make widescreen TVs the right size? Well, its not that simple. They are the right size. Those black bars are actually a part of the movie, added during the process of putting the film on DVD. Movies are shot in all sorts of different aspect ratios, the most common being 2.31:1. To fill your widescreen TV, you want DVDs with an aspect ratio of 1.85:1, especially if they're labelled anamorphic. These will fill your entire screen. Everything else will get letterboxed, but its for the quality of the picture.

LFE: Low-frequency effect, the audio track that transmits deep sounds in the 10-120 Hz range. This audio track is meant to go to a subwoofer. Its primary responsibility: bass. Its where your booms, thuds, and bangs come from. Without it, you'll be missing out on the complete surround sound experience.

LCD: A Liquid Crystal Display uses an LCD screen made up of colored pixels that are lit by a light source behind them. The problem with LCD technology is that there will always be backlight, so creating true black color is difficult since black is the absence of light. Either way, LCDs produce a clear picture with a great color depth. LCDs also use less electricity than most other TV technologies.

LCD Projection TV: These TVs use rear projection technology in connection with an LCD screen. This creates an inexpensive yet powerful TV with a good color depth, high contrast ratio, and deep black color. They still have lamps that need to be replaced every few years like other projection sets.

LCoS (Liquid Crystal on Silicon): Similar to DLP, an LCoS TV uses liquid crystals instead of mirrors. The crystals are applied on silicon chips with aluminized material on them. There is also a highly reflective layer on these chips. The image you see on your TV is reflected off of these liquid crystals and on to the screen. It is less expensive to make LCoS TVs than traditional LCD or plasma TVs and they can provide higher resolutions. LCoS may play a large part in the future of high definition televisions. It is another form of a micro-display, meaning it has a slim profile (just a few inches thick).

Luma: Luma is the black, gray, and white information in a video signal (represented by the letter Y). This is one part of the transmission of color (luma for brightness and chroma for color).

N

NTSC: Used by the United States, Mexico, Canada, Japan, and a handful of other countries, it is the analog television system created by and named after the National Television System Committee. Basically, almost every TV that is non-digital has an NTSC tuner inside to allow it to receive analog television broadcasts. Now, you'll want a TV with an ATSC tuner to receive digital broadcasts (which do not necessarily include high definition; HD uses the same system as other digital, non-HD broadcasts).



O

OLED TV: A new technology soon to hit the market of high definition TVs, Organic LED-based TVs are going to be thinner than LCDs, require no backlight, and require the very least amount of electricty compared to other types of TVs. They will also sport the best possible picture quality, from black level to contrast ratio to color depth.

P

PAL: An alternative to NTSC, PAL stands for Phase Alternating Line. It is largely used over seas and in South America. Australia, China, parts of Africa, and much of Europe uses PAL. There's not much of a difference between PAL and NTSC (though PAL has a higher resolution) other than the fact that they are not compatible with each other.

Pan and Scan: Similar to letterboxing, pan-and-scan actually crops an image to fit on your screen by having a camera literally pan and scan over the film, frame by frame, selecting areas of interest for the viewer to watch. What's happening is you are losing parts of the image while the camera focus is changed to make the picture fit on your screen. This is common with standard definition TVs playing widescreen DVDs. Letterboxing is much more common now and allows you to view most of the image (but you will always lose parts of the horizontal edges with a widescreen DVD on a non-widescreen TV).

Pixel: A combination of "picture element", a pixel is one point on a graphic display. They are usually square but can sometimes have non-square aspect ratios, and they can be seen when viewed up close or magnified. How many pixels are on your screen make up your screen resolution. The more pixels you have, the more detail in your display. Pixels usually have three color dimensions (red, green, blue) so that they can blend to produce any color necessary.

Pre-Amp: A preamplifier is usually found within receivers and acts to switch between different line level sources, applying a volume control in the process. It doesn't have to actually amplify anything (as there is usally a built in amplifier for this purpose). They can be found in or beside (external to) other devices like microphones and turntables.

Progressive Scan: As home theater is concerned, progressive scan draws the lines of an image one by one. This is contrast to interlacing, which draws all the odd lines then all the even lines in rotation. Progressive scan consumes more bandwidth because you're getting the whole frame every time, resulting in the highest quality image.

Projector: Without need for a technical explanation, projectors are most often called "front" projectors. They're the same idea as what you see in a movie theater - the image is projected on to the screen. This is contrast to rear projection, which reflects a projected image onto the screen you're looking at (like a Projection, or rather Rear Projection TV). Front projection is only available as you've seen in theaters with a projector on one end of the room and a screen on the other. A rear projection TV (RPTV) actually projects the image from behind the screen.

Projection TV: See projector above.

Plasma TV: Known as PDPs (Plasma Display Panels), plasma TVs contain many tiny cells held between two glass panels. These cells contain a mixture of nobel gases (xenon and neon). These gases are electrically stimulated to turn into plasma, and this plasma acts to excite phosphors on the front panel of glass to emit light. Its a complex system that results in fantastic picture quality and very thin display panels. On the downside, plasma generates a lot of heat, consumes a ton of electricity, can suffer from burn in, and may not last as long as other TV technologies.

Q



R

RCA Cable: There's really no such thing as an RCA cable. The idea comes from RCA connectors, found on the end of most home theater cables (composite, component, digital coaxial, and more). It is actually dervied from the Radio Corporation of America which designed it in the 1940s. Its original intent was to allow phonograph players to connect to amplifiers.

Receiver: Typically called an audio/video receiver, the home theater receiver is the driving force behind your surround sound. You can also (usually) plug your video components into the receiver for audio/video switching. This means your DVD, cable/satellite box, game console, and whatever else can plug into the receiver. This way, you have just one cable plugging into the TV, allowing you to "switch" video sources from the receiver. You already run your audio through it, so it only makes sense to run the video as well. Not all receivers support the digital video inputs like DVI and HDMI, however, so its not always best for high definition video (especially when you need more than one HDMI or DVI input). Receivers contain an amplifier inside to power your speakers. They also have the audio codecs (like Dolby Digital) to decode the audio soundtracks on DVDs and play them in surroud sound. Receivers are often very large and heavy, making it obvious which component in your system is the receiver.

Region Code: Also known as a DVD region code. They can be seen as Region 1, Region 2, Region 3, and so on. The US uses region one. Most DVD discs are encoded with one of these codes. They act to restrict the area of the world that they can be played. If a disc can be played anywhere in the world, they are Region 0. The reasoning for this in two fold. From one side, region codes prevent pirating of DVD movies across different countries. From the other side, it helps movie studios better provide different regions the products they need, like DVDs dubbed in other languages or with region-specific content. Most DVD players can be modified to be region-free but they cannot be purchased region-free (region-free would allow the player to utilize any region setting).

Resolution: Referring to the number of distinct pixels that are on a computer monitor or television screen. A CRT television doesn't actually have pixels, but rather scan lines. DLP, LCD, plasma, and LCoS TVs have fixed pixel arrays, meaning if content is played outside of their resolution (usually below it), than the content must be digitally scaled to use the available resolution. This is why a normal television broadcast looks so grainy and broken up on a high definition TV (unless its a CRT TV, which again, has no pixels). Resolution will either be 480p, 720i, 720p, 1080i, or 1080p. This can also be represented by expressing the pixels as you would a desktop monitor, such as 1280x1024. For TVs, 1080p resolution, for one example, is represented as 1920x1080. This means there are 1,920 pixels in each horiztonal row and 1,080 pixels in each vertical row on the television. The larger the screen, the same number of pixels, resulting in larger pixels. This is where competing TV technologies attempt to make their pixels look smoother and more detailed even at a larger size. This is why you need to sit an adequate distance from your TV, because if your 70" plasma is 1080p playing high definition content, it will still look blocky and blurry up close.

S

SRS TruSurround: Now known as TruSurround XT. TruSurround isn't surround sound; in fact, it is found on 2-speaker televisions. What it does is takes surround sound tracks and converts them to two-channel, simulated surround sound. It acts to direct the sound in such a way to make you think you're actually surrounded by speakers. Does it really work? No, but it does sound better than plain old stereo sound.

S-Video Cable: Separate video, also known as super video. It is an analog video signal that carries two separate channels; brightness and color. It uses a 4-pin mini-DIN connector (you've seen it; larger than a typical RCA connector with the pins inside). S-video is marginally higher quality than composite video but is also unable to carry a high definition signal.

Subwoofer: A sub is responsible for playing strictly LFE sounds. This would be your bass, or frequencies from 150 Hz to 20 Hz. You'll want a powered subwoofer (one that uses an AC power connection) that is at least 10" in diameter to produce quality bass. Speakers themselves can create bass, but the problem is most of them have drivers that are too small and thus do not displace enough air to generate the typical "thudding" you get from a subwoofer.

Surround Sound: Also referred to as multichannel audio. Surround sound utilizes multiple channels (speakers) to play back sound that literally "surrounds" the listerner. Common surround sound is 5.1, meaning 2 front speakers, 2 rear speakers, a center speaker, and a subwoofer. Most DVDs are encoded in 5.1, but some movies (and receivers) support 6.1, 7.1, and beyond. To play audio in true surround sound, you need to use a digital connection like fiber optic or digital coaxial from your source to your receiver. Analog cables only allow for stereo surround, or false surround sound.

SXRD: Silicon X-tal Reflective Display, developed by Sony. Similar to DLP, SXRD uses liquid crystals on silicon chips instead of mirrors to reflect the image on to the screen. It results in high quality images and low-profile displays (also known as a micro-display).



T

TOSLINK: Basically, TOSLINK is your typical fiber optic cable. There's no difference. TOSLINK is just the official name for the standard that fiber optic cable is created under for audio purposes.



U

Universal Remote Control: If you're tired of using one remote for the TV, another for the DVD player, and yet another for your cable box, by a universal remote control. There are hundreds of varieties of them and many support thousands of devices. You can easily program a universal remote to control all your home theater accessories. Some devices even come with universal remotes, especially some receivers. Even cable and satellite box remotes are usually capable of universal control to some degree.

Upscaling: Upscaling involes the use of a video scaler (sometimes found in high definition TVs and certain DVD players). An algorithm is used to convert the resolution of a signal to the resolution desired. For instance, an HD DVD player upconverts regular DVDs (480p resolution) to 1080i resolution, resulting in higher quality. Scalers don't always improve image quality; sometimes, they are necessary to just display the content you're trying to watch. This is especially true with high definition TVs. They must scale standard definition broadcasts to a higher resolution so you can watch them on a high def TV. The quality isn't improved (in fact, it is pretty terrible), but without the scaling, it would be unwatchable.



W

Widescreen: I think by now we all know what widescreen is: the standard for high definition TVs and most new computer monitors. DVDs are commonly found in widescreen format, and high definition programming is offered in widescreen. The advantage is to see more of the picture was it was originally captured. Your standard square TV loses some of the horizontal image, so widescreen resolves this issue.