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Audio and Video Definitions

av inputs (composite): these are the standard jacks, which are used to hook up audio and video components to each other. input jacks allow the signals to be received from other components; having many inputs is helpful for future system expansion needs. audio signals using these jacks are transmitted faithfully but video signals mix color and black & white signals together. for video, composite jacks provide high picture sharpness but are not as good as s-jacks or component jacks. the composite jacks usually have colors associated with their function. yellow is for the video signal, red is for the left channel stereo and blue or white is for the right channel stereo.

am/fm: the two commercial radio systems in use in the us. amplitude modulation stations can be heard at great distances --especially at night, but are subject to interference and low fidelity. frequency modulated signals can only travel in a line-of-sight manner (generally 30-40 miles) but offer higher fidelity.

am/fm presets: these allow you to store your favorite stations in memory for recall at the touch of a button. amplifier power: measured in watts, amplifier power is used to drive speakers. all things being equal, more power will allow you to play music louder with less distortion. however, other factors can influence clarity as well.

anamorphic / 16 x 9 / enhanced for widescreen tv's: all three of these names mean the exact same thing when talking about dvd's. the studios didn't have enough sense to get together and pick one name. what do these three names mean you ask? easy, it boils down to picture sharpness. the 16 x 9 (easiest to type) has additional vertical resolution added to it. in other words, it's sharper, richer in color, and looks more like film. that was the good news. the bad news is that your tv has to have the ability to resize the picture to see the additional resolution. for the most part, only the front projectors, like the one i displayed on page eight of "my photos/ equipment", is capable of properly displaying the extra resolution. as the new hdtv ready televisions come on line they will be able to display the extra resolution by resizing your picture with a touch of a finger on your remote control. for this reason it's important that all dvd's are produced in anamorphic/16 x 9/enhanced (whatever you want to call it). if they aren't, you might eventually be stuck with a lower resolution dvd as it gets replaced with an anamorphic/16 x 9/enhanced version. don't worry, it won't happen over night.

aspect ratio: movies are filmed in different widths. for the most part they are filmed to be displayed in american theaters at two widths. widths are referred to as aspect ratios. wide and real wide. wide usually equals 1.85:1 and real wide is about 2.35:1. all this means is that the image is displayed at 1.85:1 is 85% wider than it is tall.

bandwidth @ rated power: humans, in theory, can hear sounds as low as 20hz and as high as 20khz. it stands to reason that an amplifier's power should be rated at that bandwidth, and most are. power ratings should include frequencies from 20hz-20khz. ratings that don't include this range are not giving you "real world" power information.

center channel power: the center channel handles most of the dialog and action in movies. power (in wattage) to the center channel should be similar to the left and right front power to ensure that proper balance is maintained. (your center channel speaker should be similar or the same as your left-front and right-front speakers.)

chrominance or c: this refers to the color signal.

component or rgb connectors: these use connection-types called bnc and rca connectors. they carry the rgb or red, green, blue signals separately.

composite video cable: the y and c signals are too large for this type of cable so the get reduced and combined into a single composite video cable with rca-type connectors that usually have yellow ends.

dolby® digital discrete amplifier circuitry: uses separate analog electrical components (resistors, transistors, diodes etc.) rather than integrated circuit chips to amplify the audio signal. this generally results in better sound quality with real speakers but may also increase cost. some amplifiers/receivers use discrete circuitry only in their output stages, others use discrete circuitry: this circuitry allows the decoding and transmission of the 5.1 and 6.1 [ex] channels (front right, center, front left, rear right and rear left, center rear [ex], and the subwoofer [.1]) of high-quality digital surround sound available on some most dvds and on some high definition television (hdtv) broadcasts. all dolby® digital decoders can also decode dolby® prologic sound tracks. see also: dts

dolby digital: it's basically a sound format that allows a better quality of sound. the dvd players have built in decoders so that you can hear the dolby digital sound. don't be fooled into thinking that is all you need to hear the dolby digital soundtrack. you also need a sound processor that processes dolby digital. You can't have one without the other and still listen in dolby digital. Your dvd player will have two plugs in the back that connect to the processor. One uses an optical line to get the dolby digital sound. The other uses a digital coaxial cable.

dolby digital 5.1/6.1: same as above but has multiple sound tracks. track one is the center channel. when movies are shot, believe it or not, most of the dialogue is re-recorded in the studio. it is designed to come out of the center channel. track two and three are the left and right front speakers. they are mostly where sound effects come from along with music. tracks four and five are the left rear and right rear speakers. they are also for effects and sound that occurs behind you. six [ex} is the center rear channel. each channel (speaker) works independently from each other. that was the 5. or 6. in the 5.1 or 6.1. the .1 is a subwoofer (bass) track that is designed to get in the real low sounds that make the booms and rumbles.

dolby® digital adaptable: this feature means that the necessary input jacks and amplification circuits are present so that a dolby® digital decoder may be added. since some dvd players come with decoders built in, a receiver that is dolby® digital adaptable can be used without additional investment.

dolby® pro logic: the most common surround sound system in use today. it is a three channel analog system that uses 5 and 6 speakers (front right, center, front left and three rear) that is encoded onto almost all vcr movies today as well as many television shows. to hear dolby® pro logic, decoder circuitry is needed in the receiver (or in a tv or outboard decoder) and a hifi vcr is required to play back vhs encoded tapes.

dolby pro logic ii: this surround sound decoding is designed to let you take advantage of all five speakers (right, center, left, and right and left surround) in a surround sound system even when playing stereo sources, like cds and older videotapes. in other words, it lets you get surround sound from virtually any stereo recording.

dolby® surround sound: this is the predecessor to dolby® prologic and although it uses the same 3-channel sound track, it lacks the ability to create center channel effects. as a result, the sound is less focused and dialog is less clear, but it still provides a nice overall surround effect.

dsp modes: digital signal processing uses digital circuitry to manipulate music and soundtracks to create a sense of space or different spaces. this allows you to create the illusion that a singer was performing in a concert hall or jazz club or even a stadium. some manufacturers actually recreate the acoustics of specific places so you can hear what a band would sound like playing in carnegie hall or the hollywood bowl.

dts: dts (digital theater sound) is a surround sound system similar to dolby® digital. both are based on a 5.1 and 6.1 channel surround system, but some claim dts sounds better than its rival. dd and dts use similar technologies but different compression schemes however; they are not compatible.

dvd: i have heard it called two different names. digital video disc and digital versatile disc. who cares as long as it works. it's the size of a cd, it plays movies, music videos, and gives a pretty sharp picture. it has Dolby digital (5.1/6.1) and dts (5.1/6.1), along with analog versions of sound. Dolby digital and dts are the superior sound tracks.

efficiency (spl [sound pressure meter]@ 1 watt/1 meter): a measure of how loud a speaker will play with a given amount of amplifier power. higher db (decibel) ratings mean speakers will make better use of your amplifier power. a 3 db difference between speakers gives the same effect as doubling the amplifier wattage. while more efficiency is good, be aware that efficiency has nothing to do with sound quality. speakers with efficiency ratings of 90 db or higher are considered efficient.

eq [equalizer]: allows you to customize frequencies to adjust for problematic room acoustics. frequency response: this is the range of sound that a component reproduces accurately. human beings, can hear from about 20-20,000hz with 20 being very low bass and 20,000 being very high treble.

front power: this refers to the amount of power (watts) the receiver gives to the right and left front channels, as opposed to the power given to the center and surround speakers. in most of today's surround sound receivers, the power going to all channels will be equal.

HDTV: high definition television. there are different versions of HDTV. some will bring in a sharper picture than others. you will not be able to use your present television. sooner or later you will have to buy a new tv that is HDTV ready. they have a wider screen (16 x 9). we have no control over what version of hdtv will be presented to us. the bottom line is that it will look a lot better than what you are presently looking at.

high current capability: receivers and amplifiers with high current capability are constructed with large power supplies, storage capacitors, and heat sinks. this allows them to drive speakers with difficult power demands without difficulty. high current capability is found in only more expensive receivers and amplifiers.

hi & low level inputs: this refers to the ability of a sub woofer to be hooked up directly through speaker wire connections to an amplifier (high level connection) or via standard RCA cables (low level). the preferred connection is low level, but since not all receivers and amps have this output available, the ability for a sub woofer to take either input is desirable. interlaced: this is how TV signals are displayed. it does it by displaying the horizontal lines twice by using an odd/even sequence. first the odd lines are displayed on the screen forming the image and as the odd lines clear, the even lines display. this sequence is continuous. this takes place faster than your brain can perceive. this is also why you see flickering on your TV on certain horizontal images. you can see that flickering when you see thin horizontal slits through shades on a window or someone wearing a shirt with thin horizontal lines.

laser disc: this is the eight track tape as cassettes came out. a laser disc is a larger version, a 12 inch platter, of the DVD. the technology has been passed by but some continue to hold on to their units due to the investment they have made in the library of movies.

line doubler: line doublers double the scan rate on your display, if it has the ability to do so. it doesn’t double the horizontal lines. it doubles the amount of time your picture refreshes. this is a real simple explanation that will give you an idea of what is taking place with this device. a display (a regular tv) that has a scan frequency of 15.75khz and can not be doubled. it must be at least 31.5khz in order to have the capability of doubling. these numbers become relevant usually on front projection systems. the upside of doublers (especially the better ones) is that they clean up motion artifacts and dot crawl. they also have better comb filters for color saturation and hue (tint) control and the results are more film-like. the downside is that they tend to soften the picture a bit. *the upside outweighs the downside.

line triplers/quadruplers: line triplers/quadruplers do essentially the same as doublers except that it triples/quadruples the horizontal scan rate. your display device must have the ability to scan at a frequency of 62khz in order to quadruple. the upside and downside are the same as the doubler's and tripler's/quadruple's.

line scalers: a line scaler receives one resolution from a source and automatically converts it to the best signal for display at another resolution and refresh rate. it’s also capable of doing the same thing in reverse. therefore it can double, triple, quadruple at the optimum refresh rate automatically or manually. it can also do this at any aspect ratio without cropping the picture as doubler’s, tripler's, and quadruple's do. best of all it’s a heck of a lot cheaper than doublers, tripler's, and quadrupler's. they are noticeably inferior to a pure doubler, tripler, and quadrupler. the more expensive versions like faroudja are the exception. **note: never scan higher than your device is capable of displaying.

line triplers: line triplers do essentially the same as doublers except that it triples the horizontal scan rate. your display device must have the ability to scan at a frequency of 43khz in order to triple. the upside and down side is the same as the doubler.

luminance or y: this refers to the black and white signal (bright or dark).

multi-brand/universal/multi-component remote control: these remote controls have the capability to control multiple components from different manufacturers. most such remotes have the necessary "codes" built in. others "learn" the codes required from your existing remotes. some advanced models learn new codes you need via touch-tone through a toll free phone call.
  • remote controls: • basic: these remotes control only the component ( in this case the receiver) it came with. • universal: these have the ability to control audio components in addition to the receiver, almost no matter what the brand. some are programmed by punching in a code that lets the remote know what components you have, and some are "taught" the functions by placing the universal remote and the component's original remote head-to-head. • a/v universal: like universal remote, these will operate other components from other brands. the difference is that these will also control video equipment like tvs, vcrs, and dvd players. • advanced universal: these are universal remotes with some other special feature. these special features may range from lcd screens that let you know what you're controlling to rf transmission that allows you to control the component from another room. note: remote controls can only operate remote control compatible equipment. multi-room/source capable: this capability allows you to play different music in two or more rooms simultaneously. optional infrared "repeaters" allow the person in the bedroom to control the receiver from the "secondary" room.

    non-interlaced or progressive scanning (p): non-interlaced monitors (computer screens) best display detailed non-moving images. it displays all of the lines at one time. you don’t get the flickering as you do with interlaced images. a large variety of refresh rates and colors are available.

    pre-out/main in: the preamp output jack allows you to send an unamplified signal out to another audio component. this lets you hook up a signal processor such as an equalizer or surround sound decoder and then route the modified signal back in through the input jacks for amplification. you can also send the signal to a separate amplifier. this is a great feature if you plan to connect separate stereo systems in different rooms or if you plan to upgrade to a separate powered amplifier.

    rf signals: rf (radio frequency) connections are the low quality connectors used for cable boxes and tv.

    s-video or y/c: this carries and separates the luminance (refers to the black & white information) and chrominance (refers to the color information) signals while maintaining the better video quality. your set top boxes and dvd player has a variety of audio outputs and video outputs.

    sub woofer output: this jack sends a preamplified signal to a subwoofer for amplification. this method provides the subwoofer with a dedicated signal.

    surround power: specification for how much power is available to the speakers designed to be behind and or beside you in a home theater system.

    surround sound: refers to multiple sounds surrounding the listener with from different areas within the room, depending on what was recorded on the original sound track

    surround sound modes: surround sound mode effects built into the processor to enhance your music and movies, when you're not watching a dolby® pro logic or dolby® digital-encoded movie. some include: simulated or matrix surround, jazz club, stadium & hall.

    thd% @ rated power: total harmonic distortion (thd) rated as a percent of the total musical signal. distortion is bad and we want to keep it as small as possible, but lowering thd (which is only one type of audible distortion) can raise other types of distortion. amounts of thd below .1% are almost universally agreed to be inaudible. thd is always measured at full rated power (or watts), over the full frequency range (bandwidth), to assure that distortion remains low even at loud volume levels and through the entire audible musical spectrum.

    thx: lucasfilm inc. has developed a certification process for audio and video components that meet their high standards for home theater performance. thx-certified components incorporate specific performance features and circuits designed to compliment and enhance other types of surround sound systems, like dolby® pro logic and dolby® digital.

    total power: this non-standard specification is achieved by combining the power output of all channels. for instance, a 5-channel surround sound receiver that can give each channel 100 watts can be said to have 500 watts total power. video display of receiver audio settings: many receivers today have a video output to a tv set. this allows you to see any settings you change with your remote on your tv screen rather than the smaller fluorescent or lcd display on the receiver.

    video inputs/outputs: these inputs allow for the delivery of picture information into and out to a device. your receiver should have enough inputs for all the video sources you plan to connect (satellite, vcr, dvd, camcorder, tv, etc.).

    watts (per channel stereo into 8 ohms, 20-20,000 hz w/< .1% thd): by government standard, all home receivers and amplifiers must state the power they produce in watts per channel. they tell you how much electrical resistance is being imposed, what frequency range it is capable of reproducing at this power (beware of amps that leave off the bottom octave!) and with how much total harmonic distortion (look for under .1%).

    watts front/# of channels: in a surround sound receiver there are three front channels: right, center, and left. for best results, each channel should have equal wattage.

    watts rear/# of channels: in a surround sound receiver, the rear or surround section may have one mono channel, as in dolby® pro logic, or two channels (rear right & left), as in dolby® digital (ac3). because the rear channels aren't full frequency bandwidth, rear channel power in a dolby® pro logic system is quite sufficient at less than half of front channel power. in dolby® digital system, however, the rear and front channels should have similar power.

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