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November 1999 What's Up With Video Cables? Video Interfaces Composite Video – A single cable connection almost always uses RCA connectors. One wire carries the Luminance signal (black & white image) and two color difference channels (chrominance). This technology has been around the longest and is the worst interface for video since all three of these signals share one wire. Composite video using a generic video cable gets a 1 on a 1 to10 scale for video image quality. 1 being the bottom of the performance scale. S-Video – This technology was introduced in the late 1980’s but at that time it was poorly implemented in many products. More recently, S-Video connections have become consistently good and can sometimes be quite stunning. S-Video puts the Luminance signal on one wire and the two chrominance signals on another wire. S-Video would have been less annoying if two RCA connectors had been the connection of choice. However, the electronics industry decided to annoy people by adopting a nasty circular multi-pin connector that is difficult to make and difficult to use. As a result, many high-end cable companies have been slow to bring high quality S-Video cables to the market. Overall, S-Video is a fairly noticeable step up from Composite… let’s call it a 5 when you use a generic S-Video cable. Component Video – This technology involves three separate wires carrying three separate video signals: Luminance on one wire, chroma one on the second wire and chroma two on the third wire. This is the native operating mode of today’s direct view monitors. Rear projection sets or front projectors using 3 CRTs can have Component or RGB as their "native mode." This depends on whether the product originated from a design that started with computers in mind or not. Computer-based projection sets use RGB connections. Projection sets designed from scratch for consumer video use will have component video connections, if there is a 3-cable connection choice. Component or RGB offer theoretical advantages by having all three signals traveling on three separate wires. Here the connections can be confusing: Some have RCAs and others employ BNC, a type of twist and lock connector that is especially well suited for video signal transmission. If you decide to get Component cables, be certain you know what connectors you need at both ends of the cable. Component video deserves about a 7 when compared to the other two interfaces when using three generic cables for the connection. Improvements one can expect from Component Video connections include some additional clarity of the image and some slight improvement in color rendition. These two factors may appear as a sharper image to some people, however, when test patterns are examined closely, there is nothing concrete to indicate better detail. So there you have it, composite video is the anchor man. S-Video is a significant step forward. If your video equipment properly implements S-Video connections, I would urge you to take the plunge and upgrade if you are presently using composite video cables. Component Video connections approach the limits of resolution of today’s video standards. Composite is better than S-Video, but not by a lot. How About Some Cables? Let’s look at a crop of video/digital cables for composite and S-Video and see how they compare on the same numeric scale. Can you get a composite cable that gives a better image than S-Video? Composite cables
Next stop in composite land is the former composite video champion, Cardas’ $269 Lightening digital/video cable. This long-term video reference cable now gets a 3.5 rating; it is still an excellent looking video cable. I have seen ads for a low cost Cardas Lightening but have never seen that cable myself and I’m not sure if it is the same Lightening or a lower performance model in the same line. I loved Cardas Lightening for quite a while for it’s obvious jump forward in image quality compared to other composite video cables. It produced clearer images with better color rendition. It was the first video cable I used that actually gave images a sense of roundness and dimensionality because of the way the edges were rendered against the background. The next category can be best defined as
"quite a bit better than freebie composite cables." However, the images do not
rival those of Cardas Lightening or Nordost Optix. DH Labs D-75 ($75 for 1 meter, shown in
picture below right), Steve Rochlin’s MR-1 digital/video cable ($50 if Steve makes it
for you, DIY instructions available at www.enjoythemusic.com,
this cable is actually a bit better as a digital audio cable),
Illuminati/Kimber/Illuminations On to S-Video Monster S-Video 2 (approx. $30) is the standard, "decent" S-Video cable. I give it a 5.6 rating since it gives a pretty impressive performance for a cheap S-Video. Yet, things get more interesting with the Harmonic Technology Crystal S-Video ($60/2m) where you see some nice improvements. I give it a 6.1, for solid S-Video performance. This cable gives a very film-like image, not the last word in sharpness. Crystal S-Video looks a little like a romantic film which was shot for color and languid feeling rather than for razor sharp focus -- very attractive and very well saturated colors. If you want this romantic flavored S-Video image, this could be your cable. Top honors in S-Video (so far) goes again to Nordost for their Optix S-Video ($249). This cable gets a solid 6.8, pushing the envelope on hallowed Component video ground. Optix-S is clearly the most dimensional of these S-Video cables. Layering in well transferred DVDs is presented in a way that is more convincing than with other cables ( ditto textures, star fields, chrome and shiny paint on cars). Objects also have a "snap" to them that other cables do not capture. Optix-S is also a detail champ. Problems in the video image have nowhere to hide when using Optix-S. Every last detail is right there. The edges of scan lines in non-doubled/etc. displays get so sharp that they just may become visible at closer viewing distances than with other cables. It made me glad to not have to move the monitor any closer to the listening position than it already was. Optix-S uses two of the Optix composite cables twisted together and jacketed. A great looking S-Video cable for the person looking for maximum detail, dimensionality, color range, black blacks and great gray scale performance. A note about S-Video cable handling. In general, most S-Video cables are just not as robust at the connector as you are used to with cables having RCAs on the ends. Because of this, S-Video cables are more likely to be damaged by twisting, turning or bending the cable close to the connector. This is not the cable manufacturers’ fault, the lame multi-pin S-Video connector is just a pain in the butt and there is no easy way to make a secure termination at the connector. Handle your S-Video connectors only by the metal part of the connector and you’ll be a lot happier for a lot longer. Conclusions I hesitated to use a numerical rating scale for interfaces and cables, but it saved at least three pages of descriptive text that wouldn’t have given you any further information. I reserve the right to revise this scale at any time in the future. The only time it is valid is as I write this. I haven’t covered specific Component cabling here because my brief forays there were limited to using DIY cables made from identical coax and connector, a single for composite, a double for S-Video, and a triple for component video. That’s how I arrived at the 1, 5 and 7 ratings for the 3 interfaces. I based it on how identical cables performed at carrying the video signal three different ways. However, the frequencies for Component video signals are the same as for Composite and S-Video, so the cables that look good on composite or S-Video will be the same cables that look good in Component video. Video cables make worthwhile differences in image quality, but interestingly, they seem less sensitive to outside influences than audio cables. Laying a video cable on the carpet doesn’t cause a difference in image quality that I noticed compared to suspending the cable in air. If you do that with audio cables, you hear something. With video cables, not much happens with image quality unless you do something technically incorrect like lay the video cable parallel to and close to an AC power cord for any significant distance. Furthermore, video cables don’t seem to undergo any obvious break-in period like audio cables do. I noticed no change in video image quality as the cables "aged." That’s it for this installment. Now go out there an find some better image quality! Website links to manufacturer sites:
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Let’s start at the top
with Nordost’s $99 Optix (shown right). This gets a grade of 4 for being the best
possible composite video cable I’ve tried so far. This very thin cable has clarity,
snap, and dimensionality that gives you composite video image quality that is as good as
you are likely to get. Optix uses Nordost’s recently developed wire construction
technology. A Teflon™ thread is wrapped around the conductor in a wide spiral. A
Teflon™ jacket is pulled tightly over the spiraled string leaving air as the
dielectric over quite a bit of the surface area of the conductor. The small size results
in a light weight. The cable is quite easy to work with and seems far more durable than
its tiny size would first indicate. Nordost explains that this is due to the strength of
the Teflon outer jacket.
DV-30 (under $75 est.), and XLO/VDO (approx. $50). All of these cables get a
solid 2 rating. Freebie/generic composite video cables are universally no better than a 1
though I would almost be willing to give them a -1 to indicate that they actually worsen
the image. These cables produced a serviceable image considerably better looking than
freebie cables, yet depth, color and blacks were not up to the high standards of the Optix
and Lightening cables.