A process which improves the look of film-based video when it is converted to progressive-scan. The frame rate for film is 24 frames per second (24 fps), and that's the way movies are stored on DVD. The frame rate for broadcast video in the U.S. is 30 frames per second (or more precisely, 60 fields per second). So, one of the primary tasks of the MPEG decoder inside every DVD player is to take the 24 fps data stored on the DVD and convert it to 60-fields-per-second video for TV viewing. Since 24 doesn't divide evenly into 60, a process called "3-2 pull-down" is employed, where 3 video fields are created from the first film frame, then 2 fields from the next frame, then 3 then 2, 3-2-3-2-3-2, etc. The result is 60-fields-per-second interlaced-scan video, and that's the end of the storey for non-progressive-scan DVD players. Progressive-scan DVD players add an important additional step to create a better-looking picture - they generate a progressive-scan video signal through a process called de-interlacing (sometimes called "line-doubling"). The de-interlacer's first task is to look at the interlaced video signal as it leaves the MPEG decoder and determine whether it's original source was 24-frame-per-second film or 30-frame-per-second video. The original frame rate determines the type of processing necessary to create an optimized progressive-scan signal. Advanced de-interlacers detect 3-2 pull-down on film-based sources and apply 3-2 pull-down processing to create a 60-frame-per-second progressive-scan signal that maintains the original frame integrity, with no mixing of non-matching fields. This processing eliminates jagged edges on still objects and moving angled lines, producing video with the naturally smooth look of film. Other names for 3-2 pull-down processing include "3-2 pulldown detection," "3-2 pull-down compensation," and "3-2 reverse pull-down."
5.1 Channel
Refers to surround sound formats that use five channels ("5" designation) of full frequency sound and one channel (".1" designation) for low frequency effects (LFE). Examples of 5.1-channel surround sound formats are Dolby Digital and DTS.
A/V
Audio/Video
Amplifier
A device, especially one using transistors or electron tubes, that produces amplification of an electrical signal.
Analog
Almost everything in the world can be described or represented in one of two forms: analog or digital. The principal feature of analog representations is that they are continuous. In contrast, digital representations consist of values measured at discrete intervals. Digital watches are called digital because they go from one value to the next without displaying all intermediate values. Consequently, they can display only a finite number of times of the day. In contrast, watches with hands are analog, because the hands move continuously around the clock face. As the minute hand goes around, it not only touches the numbers 1 through 12, but also the infinite number of points in between.
Anamorphic
A type of widescreen display format commonly found on DVD movies. It is optimized for playback on a TV with 16:9 aspect ratio (or TVs with a "vertical squeeze" viewing mode like Sony's 16:9 Enhanced). On a standard TV, anamorphic material look horizontally squeezed. Anamorphic DVDs are often labeled on their cases "enhanced for 16x9 televisions," "enhanced for widescreen televisions," "16x9 anamorphic," or "anamorphic widescreen." An anamorphic widescreen DVD has significantly higher resolution than a letterboxed widescreen DVD. For example, for a film shot in the commonly-used 1.85:1 aspect ratio, a letterboxed DVD presentation uses only 345 vertical scan lines (the remaining scan lines are taken up by the horizontal black bars above and below the image). That same film in anamorphic widescreen will use anywhere from 460 to the full 480 scan lines.
Anti-Skip Memory
Memory that a digital audio player, CD or MP3 player, uses to store the musical data it reads from the disc. A digital audio player reads musical data from the disc, stores it in memory, then plays it back from the memory buffer, which results in less skipping caused by bumping or vibration. The more seconds of storage time in the buffer, the more protection against skipping.
Aspect Ratio
The shape of an image or display screen expressed as a width-to-height ratio. The NTSC television standard is the familiar squarish 4:3 (1.33:1), while anamorphic DVDs and High-definition TV broadcasts are in the wider 16:9 (1.78:1) shape. Most movies are made for the wide screen of a theater, and are originally displayed at the wider ratios of 1.85:1 or 2.35:1. DVD's huge data storage capacity makes it possible to include multiple version of a move on a single disc. It's not unusual for a DVD disc to feature a Standard (4:3) version on one side and a Widescreen version on the other. For TVs with standard 4:3 screens, moves (whether on disc or tape) must be re-formatted to either "letterbox" or "pan-and-scan." If you usually rent or buy VHS movies, you're probably used to pan-and-scan versions, which are preceded by this message: "This film has been modified from it's original version. It has been formatted to fit you screen." Pan-and-scan provides an image with full height, but shows a central "window" that is only 75% of the original widescreen width. What this window shows is deteremined by the preferences of the person(s) performing the film-to-disc transfer. Widescreen DVDs will be either letterboxed or anamorphic. For letterboxed DVDs, the player uses a "letterbox filter" that adds horizontal black bars to the top and bottom of the picture. What you see is a short, rectangular image that maintains the movie's full original width.
AUX
Stands for Auxiliary port
Bitstream
A signal that contains digital data in its undecoded state. An example is the signal that's fed through a DVD player's digital output(s), which carries Dolby Digital, DTS, or PCM signals.
Built-in condenser (Microphone)
Condenser (or capacitor) microphones use a lightweight membrane and a fixed plate that act as opposite sides of a capacitor. Sound pressure against this thin polymer film causes it to move. This movement changes the capacitance of the circuit, creating a changing electrical output. In many respects a condenser microphone functions in the same manner as an electrostatic tweeter, although on a much smaller scale and "in reverse." Condenser microphones are preferred for their very uniform frequency response and ability to respond with clarity to transient sounds. The low mass of the membrane diaphragm permits extended high-frequency response, while the nature of the design also ensures outstanding low-frequency pickup. The resulting sound is natural, clean and clear, with excellent transparency and detail.
Cannon Connector
Cannon Connector has three pins and provides a balanced input, as opposed to an unbalanced or single ended RCA connector. It's the standard connector used for all professional microphone wiring and some line level wiring. Typically indicates balanced wiring. Standard microphone wiring is for pin 1 to be the shield, pin 2 is the + (positive/hot), and pin 3 is - (negative).
CD
Abbreviation for Compact Disc, a compact disc is a polycarbonate with one or more metal layers capable of storing digital information. The most prevalent types of compact discs are those used by the music industry to store digital recordings and CD-ROMs used to store computer data. Both of these types of compact disc are read-only, which means that once the data has been recorded onto them, they can only be read, or played.
CD-R
Short for Compact Disk-Recordable, a type of CD disk that enables you to write onto it.
CD-RW
Short for CD-ReWritable, a type of CD disk that enables you to write onto it in multiple sessions. One of the problems with CD-R disks is that you can only write to them once. With CD-RW drives and disks, you can treat the optical disk just like a floppy or hard disk, writing data onto it multiple times.
Chrominance
The color information portion of a video signal that describes an image's color shade and vividness.
Compact Midsize Chasis
Also called case, a compact midsize metal frame that serves as the structural support for electronic components.
Component Video
A video signal in which the brightness (luminance) and color (chrominance) portions of the signal are processed separately. Component video signals provide greater color accuracy than S-video or composite signals. Why is component video superior to S-video? Where S-video separate the luminance and chrominance portions of the signal, component video goes a step further and splits the chrominance portion into two components. The benefits - improved color accurancy and less color bleeding - are especially noticeable on larger-screen TVs.
Composite video
A video signal in which the brightness and color portions of the signal are combined. Examples of composite video include standard VHS, laserdisc, and regular broadcast TV. A DVD player's standard RCA-type video jack provides a composite video signal.
Copy protection
A system for preventing the unauthorized reproduction of copyrighted media like movies or music. The DVD format includes both digital and analog forms of copy protection. You will probably not be able to copy DVDs with your VCR. (In fact, because the copy protection system is triggered by a circuit found in most VCRs, simply playing a DVD and running the signal through your VCR will often result in a distorted picture. You should bypass the VCR altogether and connect your DVD player directly to your TV.)
D/A Converter
An electronics component that coverts digital signals into analog signals. This is used in CD players and receivers to convert the digital input signal into an analog output signal that can be used to produce sound.
DBBS
Abbreviation for Dynamic Bass Boost System. Sophisticated electronic circuitry calculates the available amount of bass boost at the selected volume level, to provide maximum bass with no distortion at high volume settings. From a whisper to a scream, Digital Dynamic Bass Boost delivers the maximum bass punch.
De-interlacing
The process of converting and interlaced-scan video signal (where each frame is split into two sequential fields) to a progressive-scan signal (where each frame remains whole). De-interlacers are found in progressive-scan DVD players and digital TVs. More advanced de-interlacers include a feature called 3-2 pulldown processing. With TVs, de-interlacing is sometimes referred to as "line-doubling" or "upconversion."
Digital Output
All DVD players include at least one digital audio output for sending the Dolby Digital or DTS bitstream to a compatible decoder (which is usually built into an A/V receiver). Digital data transfer offers extremely wide bandwidth, immunity to RF interference, and an easy one-cable connection. The two most common types of digital output are coaxial and optical. Although a coaxial digital jack looks like a standard RCA-type audio jack, both coaxial and optical jacks require special cables to connect to the digital input of your Dolby Digital/DTS-equipped receiver. Note: Most DVD players do not included digital cables.
Digital Security Code
A digital security code, which is randomly generated each time the handset is placed in the base unit. This code is continually transmitted between the handset and base unit, preventing someone else from accessing your phone line, listening to your phone conversations or placing unauthorized phone calls.
Digital-to-Analog Converter (DAC)
An electronic circuit that converts a series of digital "words" into a continuous analoge signal. DVD players include separate DACs for audio and video.
Dolby Digital Decoder
Decoder for Dolby Digital audio, which is a standard for high-quality digital audio that is used for the sound portion of video stored in digital format, especially videos stored on DVD-ROMs. Dolby Digital delivers 6 channels in the so called "5:1" configuration: left, right, and center screen channels, separate left and right sounds, and a subwoofer channel. This is sometimes called surround sound or 3D sound.
Dolby? Digital
A discrete multichannel digital audio standard offering enhanced sonic realism. Dolby Digital is normally associated with 5.1-channel surround sound. Though this channel configuration is common, it is only one of several possible variations - a "Dolby Digital" soundtrack can mean anything from 1 to 5.1 channels. If you're specifically looking for titles with 5.1 soundtrack, you should carefully read each DVD disc's packaging. Relatively few older movies with stereo or mono soundtracks will be remastered with 5.1-channel surround for DVD. Dolby Digital 5.1 soundtracks will in most cases provide the most satisfying sound quality for a home theater system. It is referred to as a 5.1-channel system because it offers five full-bandwidth channels (including true stereo surrounds), plus a "low frequency effects" subwoofer channel. Unless your DVD player has its own built-in Dolby Digital decoder, you'll need to connect your player to a receiver or processor that can take the digital bitstream from the disc and convert it into 6 channels of audio. Dolby Digital uses a data compression technique called "perceptual coding" to reduce the original amount of audio data by a factor of about 10:1.
Downmixed Audio
If you don't have a Dolby Digital system, you can still enjoy excellent Pro Logic? or stereo sound. All DVD players have the ability to take a 5.1-channel Dolby Digital soundtrack and "downmix" it to two channels, which can then be sent to a stereo TV, a stereo receiver, or to an A/V receiver with Dolby Pro Logic decoding.
DTS? (Digital Theater Systems)
DTS is a well-established multichannel audio format in movie theaters, but not as common in home theater applications. Like Dolby Digital, DTS is primarily a 5.1 =-channel format. The compression scheme used in DTS "throws away" significantly less audio data than Dolby Digital, so theoretically it should sound better, but so far, side-by-side comparisons have been inconclusive. Nearly all new DVD players are DTS-compatible; some players and nearly all new A/V receivers include DTS decoding. Still, the number and availability of DVD titles with DTS soundtracks remains somewhat limited.
Duplex Channels(40 Duplex Channels)
Voice flows in both directions compared to half-duplex, for which voice flows in one direction.
DVD
Abbreviation for Digital Video Disc.
DVD-Audio (DVD-A)
A music-oriented DVD format that can carry up to 6 channels of 96kHz/24-bit audio (music for 5.1-channel home theater systems), or 2 channels of ultra high-resolution 192kHz/24-bit audio. Most DVD-Audio discs also carry lower-resolution Dolby Digital or stereo soundtracks for playback on DVD players that lack DVD-Audio decoders. A DVD-Audio disc may contain liner notes, lyrics, menus, and still pictures that display on you TV.
EQs
Abbreviation for Equalizer. An equalizer will allow you to do some final tweaking of your system by boosting or attenuating certain frequencies in order to smooth out peaks and dips in your response curve.
Extended Frequency Response
Extended the frequency range (how high and low) a driver or speaker is capable of producing. Theoretically, the wider a speaker's frequency response, the better it sounds
Field
In interlaced-scan video, each complete frame is split into 2 sequential fields, each of which contains half the scanning lines of the frame. One field contains the odd scanning lines, and the other field the even lines.
Firmware
Software (programs or data) that has been written onto read-only memory (ROM). Firmware is a combination of software and hardware. ROMs, PROMs and EPROMs that have data or programs recorded on them are firmware.
Flash Memory
A special type of EEPROM that can be erased and reprogrammed in blocks instead of one byte at a time.
Frame
A complete, individual picture in a movie film. In a video signal, a frame contains all the picture's scanning lines.
Frame Rate
The rate at which frames are displayed. The frame rate for movies is 24 frames per second (24 fps). In regular NTSC video, the frame rate is 30 fps.
HDCD? (High Definition Compatible Digital)
An enhanced method audio recording for CDs developed by Pacific Macrosonics. HDCD claims to be able to capture 20-bit resolution. Although the HDCD-enhanced information can only be heard using a DVD or CD player with built-in HDCD decoding, HDCD discs are still playable on regular DVD and CD players.
HI-FI
High Fidelity. Most commonly used to refer to the high quality audio tracks recorded by many VCRs. These tracks provide audio quality approaching that of a CD. However, because they are combined with the video signal before recording, audio dubs using them are impossible without re-recording the video.
IC Regulated
Integrated Circuit Regulated. Another name for a chip, an integrated circuit (IC) is a small electronic device made out of a semiconductor material. The first integrated circuit was developed in the 1950s by Jack Kilby of Texas Instruments and Robert Noyce of Fairchild Semiconductor.
Interlaced Scan
An interlaced-scan video signal splits each complete picture frame into 2 sequential fields, one containing the frame's odd scanning lines, and the other containing the even line. Interlaced scan has been an effective way to maximize our 60-year-old NTSC video system, but it is prone to problems like motion artifacts, which become more noticeable on TV screens larger than 27". These artifacts are generally reduced or eliminated by progressive-scanning.
LCD
Abbreviation of liquid crystal display, a type of display used in digital watches and many portable computers. LCD displays utilize two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light.
LED
Light Emitting Diode. A semiconductor diode that converts applied voltage to light and is used in digital displays, as of a calculator.
Letterboxing
The scaling of a widescreen image to fit a standard 4:3 aspect ratio TV screen by shrinking the image so that the width fits exactly. The horizontal black bars that appear above and below the image are actually recorded with the picture, so some of the picture's vertical resolution is lost when you view it. Letterboxing is much more common on DVD movies than VHS videos.
Long Throw Woofer
A subwoofer that has a high rate of excursion (displacement power).
Luminance
The brightness component of a color video signal. Determines the level of picture detail.
MD is abbreviation for MiniDisc. MiniDisc is a versatile digital audio recording format with CD-quality sound output. It uses a special data compression format (Adaptive Transform Acoustic Coding, or ATRAC).
MP3
MPEG is the acronym for Moving Picture Experts Group. This group has developed compression systems used for video data. For example, DVD movies, HDTV broadcasts and DSS satellite systems use MPEG compression to fit video and movie data into smaller spaces. The MPEG compression system includes a subsystem to compress sound, called MPEG audio Layer-3. We know it by its abbreviation, MP3.
MPEG2
The digital video signal compression standard used for DVD. This adaptive, variable bit-rate process is able to allocate more bits for complex scene involving a lot of motion, while minimizing the bits in static scenes. The average data rate for DVD is 3.5 Mbps (million bits/second). MPEG stands for Moving Picture Experts Group.
Multi-Language Capability
DVD is designed to make it easier for movies to be distributed in multiple languages. A single DVD disc can contain soundtracks in up to 8 different languages! In addition to multilingual dialogue, a DVD also has space for subtitles in up to 32 languages. Note: the number of soundtracks and subtitles will vary from disc to disc depending on the length of the movie and whether or not the other special playback features are included.
Neodymium Driver
Neodymium provides a more focused magnetic field and weighs down the driver's voice coil less, allowing the speaker cone to move more freely. The result is better sound through more precise control of the driver.
Ni-Cad Batteries
NiCad stands for nickel-cadmium, the materials used in the battery packs for many notebook computers. NiCad batteries can provide considerable power, but they need to be recharged every three or four hours. Full recharging can take as much as twelve hours, although newer batteries can be recharged in just a few hours.
Omni-directional microphone
Literally from all directions. Microphones that can detect sound equally from all directions. When placed properly in pairs, mics with this pattern present a very real representation of stereo.
Open-Air Type Headphones
Headphones designed to let the user hear outside sounds.
Optical Output
A fiber optic digital audio connection used to connect a digital source component ( DVD player, CD player, etc.) to a receiver or pre-amplifier. The data passed is the "raw" digital audio signal using laser (light) pulses. This minimizes electrical interference and degradation. A plastic fiber optic cable called TOSLINK is used to carry the signal.
PAL/NTSC
Short for Phase Alternating Line, the dominant television standard in Europe. The United States uses a different standard, NTSC. Whereas NTSC delivers 525 lines of resolution at 60 half-frames per second, PAL delivers 625 lines at 50 half-frames per second. Many video adapters that enable computer monitors to be used as television screens support both NTSC and PAL signals.
Pan-and-Scan
A technique for making a widescreen movie fit a standard TV's 4:3 aspect ratio by showing only selected portions of the original image. This is the standard practice on VHS videos ("formatted to fit your screen"), but is less common on DVDs.
Parental lock control
Parental lock control lets parents "lock out" films by their rating code.
Parental Lockout
A small percentage of DVD movies include variable ratings capability. According to the movie rating level you select, the player will skip over certain scenes, playing the version that you choose from those available on the disc.
PCM (Pulse Code Modulation)
The digital audio signal format used for Compact Discs. Digital outputs on DVD players often labeled "Bitstream/PCM" because they can send the Dolby Digital or DTS bistream from a DVD, or the PCM bitstream from a CD.
Perceptual Coding
A type of data compression used in recent digital audio and video formats. Audio examples include Dolby Digital and MP3. The best example of video compression is MPEG2, which is used for DVD and digital satellite TV. These forms of data compression are based on sophisticated research into how we perceive sounds and images. Perceptual coding omits "imperceptible" sound and picture data which is redundant or which is judged to be masked by similar information. In the case of DVD, by "throwing away" a lot of redundant and unnecessary information, it's possible to fit multiple versions of a movie on a single 5-inch disc.
PLL (PLL Digital Tuning System)
Short for phase-locked loop, an electronic circuit that controls an oscillator so that it maintains a constant phase angle (i.e., lock) on the frequency of an input, or reference, signal. A PLL ensures that a communication signal is locked on a specific frequency and can also be used to generate, modulate and demodulate a signal and divide a frequency.
Progressive Scan
Instead of splitting each video frame into two sequential fields like interlaced scan, progressive scan displays the entire frame in a single sweep. So, where a standard DVD player's 480i output displays 30 frames (60 fields) per second, a progressive-scan player's 480p output displays 60 full frames per second. Progressive-scan picture quality is more filmlike, with more fine detail and less flicker. Not all DVD players can output a progressive-scan signal, and progressive-scan viewing requires a compatible digital TV ("HDTV-ready" or full HDTV).
Recordable DVD
The latest advance in DVD technology is machines that not only play DVDs, but record on them, too. Recordable DVD combines high-quality audio/video recording with tape-free convenience. There are three competing recordable-DVD camps, backed by various electronics and computer companies. These three camps are DVD-R/RW, DVD-RAM, and DVD+R/RW. Some of these formats use discs that can only be recorded once; others use discs that can be erased and re-recorded.
Write-once: DVD-R, DVD+R
Rewriteable: DVD-RW, DVD+RW, DVD-RAM
Region Codes
The movie industry insisted that the DVD standard include codes which would limit playback to a specified geographical region. This was done because theater and home video releases of movies do not occur simultaneously worldwide. For example, a movie may be released on video in the U.S. just as it's first appearing in theaters in Europe. DVD players have a built-in region code lockout feature, while the DVD discs may or may not contain a code (region codes are option on DVD software). A player will be unable to play a disc that has a different region code. Discs may contain codes for more than one region, or may not have any code, which allows them to be played on any player in any country. The region code for USA/Canada is "1". Note: Many recent DVDs will not play in modified "code-free" DVD players.
Reverse Polarity Protection
Protection againsted reversed polarity. A device unit will not be damaged even if the polarity is reversed. For example, a battery charger will not be damaged even if the batteries are put in upside down or bottomside up.
S-Video
Short for Super-Video, a technology for transmitting video signals over a cable by dividing the video information into two separate signals: one for color (chrominance), and the other for brightness (luminance). When sent to a television, this produces sharper images than composite video , where the video information is transmitted as a single signal over one wire. This is because televisions are designed to display separate Luminance (Y) and Chrominance (C) signals. (The terms Y/C video and S-Video are the same.)
Samarium Cobalt Magnet Drivers
Samarium-Cobalt, which is more expensive and slightly less powerful than Neodymium. However it offers a major advantage in stability with temperature, avoiding any chance of temperature related magnetic losses inside the drivers.
Signal-to-Noise Ratio (video)
This ratio is a measure of the content portion of the video signal in relation to the noise in the signal. As with audio, video signal-to-noise is measured in decibels (dB). The way the decibel scale works, if component A has a signal-to-noise (S/N) ratio of 20 dB and component B has a S/N ratio of 30 dB, component B will have ten times less noise in the signal than component A. Basically, a S/N ratio tells you how "clean" a video signal is. Because of the way they process signals, digital video formats like DVD and digital satellite TV are extremely clean. A standard VHS VCR may have a S/N spec in the low 40s; a laserdisc player, the low 50s. DVD is rated to deliver a video S/N of 65 dB!
SP/LP Mode
Short Play / Long Play Mode
Subwoofer
Refers to a specialized speaker used to reproduce the low bass frequencies for low frequency effects, also known as the ".1" channel. A subwoofer is also used in conjunction with a satellite speaker system, where the center, left, right, and surround speakers are small.
Subwoofer/Satellite Speaker System
A subwoofer/satellite combination will take up less space than a standard speaker system and offer more versatility in speaker placement. A conventional system packs all the drivers and electronics into 2 separate enclosures. With the subwoofer/satellite systems, the tweeters and midranges are housed in 2 or more smaller enclosures and the subwoofer(s) are mounted in their own specially designed box. Since the bass speaker is separated from the midrange/tweeter speakers, this configuration lets you easily place the more directional high- and mid-frequency speakers where you will get the best sound.
Super Audio CD (SACD)
A high-resolution digital audio format developed by Sony and Philips. Instead of using PCM audio encoding like standard CDs, SACDs use Direct Stream Digital? (DSD) encoding. DSD is a 1-bit technology that samples music at the rate of 2.82 million times per second, compared to standard CD's rate of 44,100 times per second. SACDs sound more detailed than standard CDs, with greater dynamic range. All SACDs contain a high-resolution stereo mix; many also contain a high-resolution surround mix, with up to 6 independent channels.
Super Thin Diaphragm Drive Unit
Diaphragm is a thin disk, especially in a microphone or telephone receiver, that vibrates in response to sound waves to produce electric signals, or that vibrates in response to electric signals to produce sound waves. An super thin diaphragm is so light it can quickly respond to the smallest signal fluctuations. As a result, this driver is extremely low in distortion and always sounds smooth and sweet -- even after many hours of listening.
Telescopic FM Antenna
Extendable FM antenna for excellent FM reception.
Tuner
A device for tuning, especially an electronic circuit or device used to select signals at a specific radio frequency for amplification and conversion to sound.
UHF
Abbreviation for Ultra High Frequency.
UL
The UL Marks are registered certification marks of Underwriters Laboratories Inc. The UL Marks may be only used on or in connection with products certified by UL and under the terms of written agreement with UL. The UL Mark on a product means that UL has tested and evaluated representative samples of that product and determined that they meet UL's requirements. In addition, products are periodically checked by UL at the manufacturing facility to make sure they continue to meet UL requirements.
Uni-Directional Pattern
This pattern is also called cardioid. As you come around the side to the back of the mic, response (volume) is diminished. This pattern is said to be uni-directional or directional. It works best in a situation where you want the off axis signal to be diminished. For instance, when you're miking a snare drum or toms on a drum kit you'd want to downplay the off-axis signal which would be the cymbals, hi-hat etc.
UPC
Short for Universal Product Code, a unique 12-digit number assigned to retail merchandise that identifies both the product and the vendor that sells the product. The UPC on a product typically appears adjacent to its bar code, the machine-readable representation of the UPC. The first six digits of the UPC are the vendor?s unique identification number. All of the products that one vendor sells will have the same first six digits in their UPCs. The next five digits are the product?s unique reference number that identifies the product within any one vendor?s line of products. The last number is called the check digit that is used to verify that the UPC for that specific product is correct.
USB
Short for Universal Serial Bus, an external bus standard that supports data transfer rates of 12 Mbps. A single USB port can be used to connect up to 127 peripheral devices, such as mice, modems, and keyboards. USB also supports Plug-and-Play installation and hot plugging.
V-Hold Control
To control the vertical position of the screen.
VAS
Short for Voice Active System.
VCR
Short for video cassette recorder.
VHF
Abbreviation for Very High Frequency.
Voice Active Recording System
A recording system that intelligently detects silence and suspends recording.
