Monster Cable Connections: Choosing Between S Video, Composite or RF For the Job

 Not too long ago, there was only one way to hook up your video equipment: the RF (radio-frequency) cable, which you can see hanging from the back of any cable box. Today, we have more and better choices: S-video cables, which carry the brightness and color signals separately; and composite video cables, which carry the signals together. And there's still good old RF cable, which carries a composite video and audio signal that's converted (or modulated) to the same high radio frequencies used by TV stations when they transmit.

Even the most sophisticated home theater enthusiasts often have misconceptions about the differences between these cables. Unfortunately, there's a good chance you could be seriously degrading the picture of your home theater system by using the wrong video cable. Choosing the wrong video cable can even degrade the sound. You might be surprised to find out that if you're using only RF cable to connect your VCR to your TV, you're only getting mono sound when you watch tapes!

The differences in performance you get with different types of video cables will depend on the equipment you own, but you can generally consider S-video cable your best option, composite video cable a good option, and RF cable the option of last resort. (With S-video and composite video cables, you need to use stereo audio cables, too, because the video cables don't carry sound.)

RF: A Necessary Evil

In general, avoid RF cable because it can seriously degrade sound and picture quality. No matter where you live, stray RF signals of all sorts - TV, FM radio, fluorescent lights, and others - bombard your video cables. These signals interact with the RF video carried in the cable. RF video occupies very high (VHF) and ultra-high (UHF) frequencies, which start in the 50-megahertz range and go up from there. All but extremely high-frequency radio waves can interact with RF video signals. This interaction can produce ghosting, and stripe and herringbone interference patterns. Also, RF video signals carry at most 330 lines of horizontal resolution, so you lose the high resolution available from laserdisc players and S-VHS VCRs.

If you use only an RF cable between your VCR and your TV, you can't get stereo sound when you play tapes, even if your TV and VCR are both stereo. Why? Because VCRs use an RF modulator to convert the sound and picture from the tape up to radio frequencies that work with the RF connection. And all VCRs have only mono RF modulators, not stereo.

In some cases, though, you have no choice but to use RF cable. Many cable TV boxes have only RF outputs, in which case you must use an RF cable. Also, if you have an older TV set or a small, inexpensive current model, there's a good chance it has only an RF input.

If you do have to run RF cable, using a top-quality cable like Monster can make a big difference. Our video cable is double-shielded, with a sturdy 95-percent-coverage copper-braid shield and a 100-percent-coverage foil shield, to effectively block stray RF signals.

Most RF cables use the center wire conductor as the male pin of the cable's connectors. This wire makes a poor connection, and usually bends easily, making the cable unusable. Monster solves this problem by using a stiff metal pin that lasts through years of use. Monster also uses precision-built copper conductors, which handle the wide bandwidth of RF video far better than the conductors many of our competitors use.

Composite: The All-Around Choice

Chances are, you should probably use composite video cable throughout most of your home theater. All VCRs and laserdisc players have RCA composite video jacks, as do most of today's TVs and receivers. Composite baseband video suffers from RF interference to a lesser degree than RF video. At baseband video's typical maximum frequency of about 5 megahertz, only low-frequency radio waves can interfere with it. Still, this interference can cause problems similar to those you experience with RF video cables, so Monster also double-shields its composite video cables to prevent interference through the cable. Again, we use only copper conductors for maximum bandwidth. Many competing video cables - even expensive high-end models - suffer from reduced bandwidth (see chart). This reduced bandwidth diminishes the high frequencies in the video signal, and robs you of the detail in your picture.

Unlike the inputs and outputs found on audio equipment, the characteristics of composite-video inputs and outputs are standardized. They all have an impedance (or resistance to the alternating current that makes up video signals) of 75 ohms. Your video cable should also have a 75-ohm impedance - as do all Monster video cables. Some cable manufacturers ignore this specification, though, using audio-grade cable and connectors instead of components designed for video. The result is that the signal can be reflected back and forth in the cable. When the reflected signal is mixed with the original signal, it cancels some video frequencies, so you can lose picture detail with poor-quality cables.

Thanks to our unique manufacturing techniques, our cables maintain a 75-ohm impedance even when they're bent or moved. We bond our cable shield to the cable's insulator, so they won't separate. With other cables, the shield often separates from the insulator, moving further from the center conductor, and thus changing the impedance of the cable. We also maintain consistent impedance by using an exclusive nitrogen-injected insulator that doesn't change shape or impedance when bent.

Many cheap RCA connectors break, loosen and corrode over time. Monster RCA video connectors, though, are made from sturdy metal parts, with corrosion-free gold plating. They feature a split center pin and a patented Turbine Design® connector, both of which keep the plug in place even if you tug hard on the cable.

S-Video: Potential Perfection

S-video cable differs from composite in that it carries the brightness (luminance, or Y) and color (chrominance, or C) signals on separate lines within the same cable. You can find S-video connections on S-VHS and Hi8 camcorders and VCRs, on better laserdisc players, on satellite receivers, and on better TV sets.

You might have heard that S-video connections are necessary to transmit the high-resolution signals from laserdiscs and S-VHS and Hi8 tapes, but that's not really true. The bandwidth of S-video is the same as that of composite video. The real benefit of an S-video connection is that it can reduce dot crawl and hanging dots-crawling edges that appear on the vertical and horizontal edges (respectively) of some colored objects in the picture.

Note that we said it can reduce these effects, not that it will. The fact is, the Y and C signals are always split somewhere in the video chain, even if you use a 1965 color TV with an old rabbit-ears antenna. Every TV has a Y/C separator built in, but using the S-video connection bypasses the TV's Y/C separator. You should use the S-video connection if your source device (such as a VCR or laserdisc player) has a better Y/C separator than your TV.

How do you tell which component - the TV or the source device - has a better Y/C separator? To start with, assume that any device that creates separate Y and C signals from the start has good Y/C separation. These devices include Hi8 and S-VHS camcorders, which create and record the Y and C signals separately. They also include DSS receivers, which decode a digital signal from satellite, and can thus produce perfectly separated analog Y and C signals. With these devices, you should always use an S-video connection if your TV has one.

How to Choose the Right S-Video Connection If Your TV Has One.

Laserdiscs contain a composite video signal that must be separatedinside the laserdisc player to produce an S-video output. The only way you can tell whether you should use composite or S-video connections here is to test them yourself. Connect an S-video cable from the laserdisc player to your TV's video input 1, and a composite cable from the laserdisc player to video input 2. Now switch between the inputs to see which looks best.

S-VHS and Hi8 VCRs can produce perfect Y/C separation, if the signals on the tape were recorded from a cleanly separated source. The VCR must separate the Y and C to record tapes off the air, and it usually does only a fair job. Some prerecorded tapes are produced with excellent Y/C separation, some aren't. If you have a TV with a good Y/C separator, using the S-video connection with one of these VCRs will only sometimes produce a better picture. If your TV's Y/C separator isn't very good, though-if you see dot crawl and hanging dots on network TV shows, for example-you're almost always better off using an S-video connection with these VCRs.

Like Monster's other video cables, our S-video cables all feature top-quality shielding to minimize interference. With inferior S-video cables, the Y and C signals can be thrown out of sync or partially mixed together in runs longer than 25 feet. Our superior cable construction lets you safely run our S-video cable in lengths to suit almost any home theater installation.

By considering the types of equipment you own, you can easily decide which type of Monster video cable is perfect for your system. For a small investment of time and money, you can get a dramatically better picture.