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A/V Surround Receiver
An audio/video component which receives audio and video signals from various individual components called "source components". It then, processes, amplifies and distributes those signals to the desired output devices such as TV and speakers. An A/V Surround Receiver also includes one built-in "source component" of its own; a tuner for AM & FM radio signals.

ATSC
Advanced Television System Committee. The group, made up of industry and government experts, responsible for development of the Digital TV standard. The standard covers specific rules and technical guidelines that must be followed by broadcasters and manufacturers of Digital TV's.

Backwards Compatible
A term used to indicate that a particular technology employed by a given hardware type or software medium in a new format with advanced capabilities can still be used on older equipment even though it's advanced capabilities would not be available. For example: all digital televisions have the ability to process older analog TV broadcast and cable signals. Another example is that DVD players can play CD's.

CRT
The most common and still the best form of video display technology. CRT stands for Cathode Ray Tube. It uses a very high voltage stream of electrons emitted from an electrode (the "cathode ray") housed in a glass enclosed vacuum (the "tube"). The electrons excite phosphors on the "screen" to produce images that we can see. Virtually all TV's ever made and literally all direct-view TV's use this technology. While the best video images that can be produced use CRT's, only CRT projectors (with the familiar red, green and blue beams of light that are projected onto a viewing screen), not direct-view CRT's can reproduce the highest resolution High Definition images. This is due to a limitation of direct-view technology itself.

Decode
To convert digital information to a form capable of being reproduced in the way intended by the content provider.

Discrete
An audio signal (channel) that is independent of all other audio signals (channels) present in the software. A stream of sounds concurrently reproduced with, but not added to or subtracted from any other stream of sounds present in the software. Discrete signals remain completely independent of all of the other signals in the path of reproduction until the speakers convert their electrical information into sound waves in the listening environment.

DLP
Digital Light Processor. A video display technology that employs a DMD (digital micro-mirror device) to create an image through which a white light beam is projected onto a screen. The DMD has millions of tiny mirrors which re-position themselves in such a way as to either reflect or block out light. A color wheel is then used to apply color to the image. Because this type of display uses white light to form the image, true black (the absence of light) is not possible. As a result, LCD displays lack the contrast ratio (the difference between the darkest and brightest images) necessary to display the most accurate, life-like video images. Virtually all of the DLP projectors sold for home theater are "one-chip" devices, meaning that they use one DMD which is shared by the primary colors red, green and blue (via the color wheel). While most people do not notice it, some individuals are particularly sensitive to the fluttering effect of the spinning color wheel and find it unacceptable. "Three chip" DLP's are far superior to "one-chip" since they have a dedicated DMD for each of the three colors. DLP is the likely technology that will be used by movie theaters that convert to digital cinema in the coming years.

Holistic soundfield
A physical listening environment where all of the sounds that reach our ears combine to give the effect that we are immersed in the midst of a real (not a reproduction) aural experience. The achievement of a holistic soundfield requires that no sound can be located by our senses as coming out of one or more speakers but is perceived as ... just there!

Integrated High Definition TV
Simply a High Definition TV with a built in digital TV tuner. No set-top box is necessary to receive and decode the digital broadcast signal since it is already present in the TV. Unlike analog TV; in order to keep the initial cost of Digital TV's more affordable, and since not all areas of the country have digital broadcast stations, the manufacturers of Digital TV's have made most of their offerings without built-in tuners. The tuner adds several hundred dollars to the price.

Interconnect(s)
A special type of wire used to carry line-level audio signals, digital audio signals, analog or digital video signals from one electronic component to another. They are usually constructed of two conductors arranged in a coaxial configuration within an outer protective jacket. Two or more are often molded together for ease of handling. Interconnects are usually electrical (i.e. made of metal wire - usually copper or silver) in nature but can be made of optical fiber which transmits light pulses from one component to the other.

Interlaced mode
A way of displaying a video image. The video image is "drawn" on your screen by displaying half of the picture information for the image thirty times per second and a second scan "draws" the other half of the image interleaving it with the first pass thirty times per second. The result is a whole image "drawn" sixty times per second with only half the video information changing at any instant. This way of scanning an image creates the window-blind effect on your screen. If you look closely at a bright image on your interlaced TV you will see tiny black lines separating bars of light in a vertical arrangement. This is most apparent when you are viewing a still graphic image like an onscreen VCR menu.

LCD
Liquid Crystal Display. A video display technology that uses electrically excited quartz crystals to form an image through which a white light beam is projected onto a screen. The LCD panel housing the quartz crystals filters the white light beam to form the image on screen. Because this type of display uses white light to form the image, true black (the absence of light) is not possible. As a result, LCD displays lack the contrast ratio (the difference between the darkest and brightest images) necessary to display the most accurate, life-like video images.

LFE channel
Low Frequency Effects channel. This is a discrete audio channel that carries only low frequency (bass) sounds from a multi-channel 5.1 or 6.1 encoded music or movie soundtrack. The sound from this channel is directed only to the subwoofer line-level output of an A/V Surround Receiver or Pre-Processor and is not amplified. This channel, when present, is usually used to reproduce the sound of explosions, earthquakes, etc. in movie soundtracks.

Line-level
An audio signal of less than 5 volts (usually less than 2 volts) that is of insufficient magnitude to be handled directly by speakers. A line-level signal are connected to an amplifier which is then wired to your speakers.

Powered Subwoofer
A subwoofer with a built-in low frequency amplifier. Most subwoofers sold today are powered.

Pre-Processor
An A./V component that pre-amplifies, processes and switches the audio and video signals from various individual source components in preparation for video display, amplification and/or further processing by separate devices. A pre-processor does not include a tuner for AM & FM radio signals or an amplifier.

Progressive Scan
A way of displaying a video image. The video image is "drawn" on your screen by displaying all of the picture information for the image sixty times per second. Computers have used progressive scan technology for their monitors almost from the invention of the PC. The monitor on which you are reading this is progressive scan. Computer monitors are generally designated as "non-interlaced" on their specification sheets which is another way of saying "progressive". This type of scanning video produces a smoother, more film-like image as compared to interlaced video.

Software
Information that is stored on a physical medium for the purpose of delivering that information to our senses.

Source Component
An audio and/or video device that extracts audio and/or video information from either a software medium or broadcast service and then prepares it for amplification or further processing by other signal handling devices in the reproduction chain.

Subwoofer(s)
A specialized speaker which is designed to reproduce only bass (low frequency) sounds. It very often includes a specialized amplifier built into its cabinet that is optimized to handle low frequencies only. Used to reproduce the LFE channel (the .1) in a 5.1 or 6.1 surround sound system.

Suspension of Disbelief
The ultimate goal of audible and visual communication systems. The point at which our brains are tricked into believing that what we are hearing and/or seeing is not a reproduction but is, in fact, really happening in our own physical space and time.

Sweet-Spot
The exact physical location of a listener to multi-channel music or movie soundtrack where the sound wave output of all of the speakers in the system converge. In the sweet-spot the volume of each speaker is identical. In addition, regardless of the physical distance from the speakers, a given pulse of sound emanating from all of the speakers at the same instant will arrive at your ears at exactly the same moment in time. In two channel (left & right) or three channel (left, right & center) systems all of the speakers should be pointing directly at the listener with no obstructions between the speaker and the listener. Laser pointing devices are often used to accurately determine that the speakers are precisely aimed. Unlike the left, right & center speakers, surround speakers are deliberately aimed in such a way that there is not a direct line between speaker and listener, however their relative volume and the arrival time of a momentary pulse of sound at the sweet-spot is matched exactly along with the front channels. The reason for the difference in aiming the surround speakers is to diffuse the sound so that ambiance effects cannot be located precisely by the listener. Ambiance, by definition, is diffused sound. Diffused sound helps to enhance the illusion of reality.

Video touch-panel
A device, either hand-held, table-top or wall mounted, which displays video "buttons" rather than physical buttons. A video touch-panel is fitted with a special type of glass which is sensitive to touch. Touching the glass over a "button" activates the function or action which has been programmed into that "button". Many video touch-panels can double as a video display of moving video images such as you would view on a TV.

More to come... stay tuned.