The wide array of Video connections available is a confusing issue. Listing from best quality connections to worst, they are: HDMI (High Definition Multimedia Interface), DVI (Mostly Computer Monitors) Component video, S-Video (Nearly obsolete), VGA (Computer Monitor), Composite video (Do not confuse with Component!), and RF Coax (The standard threaded antenna/cable connection). Nearly all late-model TVs, except portables, will have at least one RF Coaxial, one Composite, one HDMI, and one Component input. (Sometimes they combine Component and Composite, so you can use one or the other, but not both at the same time.) Remember, if you feed a low quality signal to an HDTV, the picture will not look any better, and may look worse, than a standard definition TV.
DVI and HDMI are the only two pure digital connection formats, and thus will only be present on HDTV sets or computer monitors. These will produce the very best picture quality with HDTV signals. Either will produce about the same quality, but HDMI is the current standard for TVs. HDMI can be found on DVD Players, HD Cable and Satellite boxes, and computers.
HDMI is the only format so far that transmits Audio and Video on the same cable. HDMI is Backward Compatible with DVI, and adapters are available to convert one to the other.
Since DVI has been around longer, you’ll see it on some devices that are a few years old, but not much on new stuff, except computer monitors. The DVI format is also digital, but does not transfer Audio. This means that with ALL formats other than HDMI, you will have to run a separate audio cable. (More on Audio connections later.)
Component video is the best analog connection available. Many DVD players, Digital cable and satellite boxes will have Component outputs. This requires 3 RCA (This refers to the type, not the brand) cables just for the Video signal, typically colored red, blue, and green and sold as a set. This hookup will produce Near-HDTV quality.
S-Video cables use one single cable with a round plug containing 4 pins. The quality level of this signal is quite good, up to DVD standards, but not quite up to HDTV standards. It’s now mostly obsolete, replaced by true HD connections.
A Composite video cable uses the same RCA plug as the component hookup, but only one cable is required for the video, and the cable is usually color-coded yellow. This gives a better signal than you’ll get from the antenna input of the TV, and is quite adequate for use with a VCR, but you can do better if you have a DVD player.
Finally, there is the standard “Coax” (pronounced Co-ax), short for coaxial cable, that is usually used for cable and antenna hookups. Coax is the only analog signal type that also carries the audio. This is the only jack on the TV that has screw threads on it. You will normally use this for your hookup to your antenna, cable box or satellite receiver. Always use the threaded plugs rather than the slip-on variety unless you will be swapping connections frequently. The “slip-on” type will “slip-off” after a while, leading to all kinds of aggravation.
I’ve saved VGA for last since that’s kind of a special case. VGA is the standard 15-pin connector that computer monitors use. Some late-model TVs, especially LCD TVs, have VGA inputs. Some computer video cards have an HDMI or DVI output, so there are several ways to hook up the computer to the TV. There’s a lot to be said for putting the computer in the living room. Since it’s an all-purpose tool, it’s also an all-purpose entertainment tool. You can have your entire music library on it, plus all of your home videos, plus play games on a BIG screen. It also eliminates the need for a separate TV and monitor… Unless you like to compute and watch TV at the same time, that is. Computer technology and home audio/video technologies have pretty much converged now.
Audio connections are a little simpler – The 3 types you’re likely to encounter are Digital Optical, Digital Coaxial, and Analog. Digital optical cables are fiber optic cables that carry the digital audio signal as light rather than an electrical signal. Digital Coaxial cables again use the RCA style plug and jack, and are color coded orange. Digital audio is the only way on most devices to get 6-Channel (Dolbytm 5.1) or 7-Channel (Dolbytm 6.1) sound into your home audio system. There is no appreciable quality difference between the optical and coaxial digital signals, so the choice is mostly a matter of making sure your TV, DVD player, and home theater setup all have the same style. Many such devices have both optical and coaxial, but some have only one or the other. The trend right now seems to be more toward the optical.
Analog audio also uses RCA style connectors, is limited to stereo only, and is color coded red (Right) and white (Left). Everything out there will have at least one set of these jacks. They’ll be fine if you’re happy with 2-speaker stereo, but for true home theater, you’ll have to use one of the digital audio formats.
Some older or high-end audio systems may actually have separate RCA jacks for each of the 6 Dolbytm 5.1 channels. These are rare, and usually only used by audiophiles.
This post has been adapted from my new book, “Deciphering the 21st Century,” Available now! Click here to read all about it.
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