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"Broadcast Quality"--
What does it Mean, and Why is it Good?
One of the most frequent questions we're asked is just what makes our products different from cables seen at big-box retail stores, high-end audio shops, and discount online retailers. To paraphrase it and put it in the voice of a potential customer: "What's good about your cables, and why should I buy them instead of something else?"
Over the years our product lines have diversified a bit, but one thing has remained at the core of our approach to cable: whenever professional broadcast-quality cable and connectors are available, we use them rather than the more commonly available consumer-market raw cable and connectors.
But what does "broadcast quality" mean, and why should anyone care?
What Broadcast Quality Really Means:
Anyone with a soldering iron and some wire can build a functioning cable (at short lengths, at least) for just about any application; after all, fundamentally all types of audio and video cabling are about getting a conductor routed from one device to another, carrying a signal from the output jacks of some device to the inputs of some other device. A few feet of wire, and some connectors, will meet that minimal requirement.
But quality connection, for a variety of technical reasons, of course requires a bit more. Most types of cable require effective shielding for exclusion of RFI and EMI, and the specific types of shielding which operate well at the relevant frequencies vary with the application. The electrical characteristics of the cable itself, too, come into play in different ways for different applications; speaker cables should be low in resistance and inductance; audio interconnects should be low in capacitance; video cables should meet specific impedance and return loss characteristics; and so on.
The funny thing about wire and cable is that these characteristics, which can play such an important role in delivery of quality audio and video, are all impossible to judge by just looking at the product. To really know the actual electrical characteristics of a video cable requires a bench full of sophisticated test equipment and the services of an engineer who knows how to use that equipment to generate a sweep of high-frequency signals, run them through a length of cable, and measure what comes out the other end or bounces back to the source. Two cables held in the hand may look very similar on the outside, but have very different electrical properties. And while it's nice for a cable to have good visible "build" quality, no amount of careful connectorization will help matters if the raw cable those connectors were attached to doesn't meet spec.
One might think that there would be certifications, specs, universally-agreed-to test procedures by which one could quickly decide whether a cable made for consumer a/v use was up to snuff. Unfortunately, there really aren't, and there's nothing to stop a Chinese company that normally makes house wiring from buying a braiding machine, declaring itself a manufacturer of video cable, and turning out substandard goods.
The broadcast world differs from this consumer market in a few critical respects. First, the "consumer" in the broadcast world is typically an engineer; whether he has that test bench full of gear for testing cable or not, he knows what it is, what it would measure, and how to use it if he has to. Second, the applications are critical; an engineer patching video from one end of a production or broadcast facility to another doesn't want to plug it in, see whether it works or not, and then spend a few hours debugging it. He needs cable to be dependable; he needs every foot of it to be as good as every other foot of it, and if the manufacturer says it'll carry 1080i HD-SDI signals three hundred feet, he needs to be able to rely on that claim when the rubber hits the road. Third, this is very much a nonsense-free market; our engineer-buyer isn't likely to be excited by specious performance claims that can't be measured or documented. He's likely to know which features of a cable are critical--like impedance tolerance, return loss, attenuation relative to the lengths of cable in use--and which aren't. Fourth, he buys a LOT of cable to wire just one production or broadcast facility, and he will not return to a manufacturer who lets him down where quality is concerned.
Fifth--and significantly, for our discussion--broadcast applications demand more of cable than any consumer application. Analog 1080i component video, commonly in use on high-definition consumer devices, requires about 37 Megahertz of bandwidth--plus, to be safe, a few harmonics, which gets us up into the 150 MHz region or so. Serial Digital Video, SDI--commonly run in production and broadcast facilities--requires twenty times that bandwidth, and will break down catastrophically if the cable doesn't conform to tight manufacturing tolerances. And the technical requirements of the cable aren't all; cables are handled, plugged in, unplugged, flexed, coiled, uncoiled, and generally subjected to wear and tear to an extent seldom seen in home environments, and both the cables and the connectors used in professional applications need to have durability, flex-life, and resistance to damage from handling and pulling. As much as a broadcast engineer appreciates the technical capabilities of well-made cable, he also appreciates the difference between delicate cable that fails while in use and robust cable that lasts.
These exacting needs are filled by a handful of companies that produce the best wire, cable and connectors available for professional applications; these are companies whose names are virtually unknown in the consumer audio/video world, but who are on every engineer's rolodex: Belden, ADC, Canare, et cetera. Conspicuously absent from that list are the companies that contract to Chinese manufacturers to make the cables one sees in big-box consumer audio/video retail stores, the companies that make the esoteric "high-end" cables for which a handful of people with more money than sense pay big bucks, and the multitude of Chinese wire and cable manufacturers and assembly houses that produce low-cost, but low-quality, cable for the consumer market.
How Does Broadcast Quality Cable Compare to Other Products, and Why Do Others Cost More?
The cables built for the broadcast market exceed, in their technical characteristics and specs, anything produced primarily for the consumer market. These are, literally and objectively-speaking, the best cables built by anyone, anywhere in the world. That statement surprises a lot of people, and we get a lot of questions about that; if they're the best, why do so many others, including many of the Chinese-built consumer brands found in the big-box stores, cost so much more?
Well, explaining the consumer market in anything is tricky business, and that's particularly so in the world of audio and video cable. There are a lot of theories of market psychology, and there are considerations independent of market psychology which play a role, too; for example, most people find it a lot simpler and more convenient to pick up cables at the big-box store when buying other equipment than to order them later. Also, retail margins on audio/video devices are very poor, but retail margins on cables and extended warranties are excellent, and it provides a strong incentive for equipment retailers to push cables and extended warranties. But ultimately, we can't really fully explain the consumer market phenomenon in audio and video cabling; we went into business to provide an alternative to the practices and pricing of the broader consumer market, not to jump into the middle of it ourselves.
We can, however, say something about the broadcast market, and that market is much more relevant to our pricing, which is in line with, and in most cases lower than, the pricing of cable assembly houses providing these same goods to broadcast professionals. The broadcast market is a volume market with sophisticated customers (remember our engineer, above) who know what the product should do, how to measure whether it does that, and what it costs to make. Broadcast and production professionals don't skimp on cable; a broadcast-quality SDI coaxial cable like Belden 1694A costs about four times as much as the cheapest US-made coax; but they don't spend money without a reason either, and as a consequence, the over-hyped consumer-market brands are utterly absent from the professional market. In most cases they fail to meet professional standards, and are more expensive to boot, which makes the choice very easy.
Broadcast-quality cable, then, is as good as it gets. Its technical characteristics are unsurpassed by anything else available on the market, and its pricing is lower than most commonly-available products, and lower than most people expect the best cable in the world to cost. Blue Jeans Cable is one of a handful of Certified Assemblers of Belden's broadcast-quality products, so that our customers can be assured not only that the cable is "the good stuff" but that it's been assembled to the highest professional standards.
But What About the Cheap Stuff?
At the same time, there are cheaper alternatives to broadcast-quality. In the market for audio/video cabling, just as in so many other markets, Chinese factories use the advantage of two-dollar-a-day labor from workers who have no economic or political rights to substantially underprice American suppliers, and though their quality is inferior, their pricing is unbeatable. What about them?
As we've pointed out, the capabilities of broadcast-quality cable exceed, in some cases by a couple of orders of magnitude, what is really required to carry the common consumer video standards. A component video cable sweep-tested to 4.5 GHz will easily carry analog component signals which require about 37 MHz of bandwidth; in fact, there's headroom for a hundred harmonics on top of that. The natural question arises: do we really need the cable to be that good?
The answer, of course, is no. We don't need the cable to be good enough to carry a hundred times the signal bandwidth. Something less would do, without visible degradation of the signal. But how much less will do, and how can we be sure of the quality of what we're getting? That, as it turns out, is the tricky question, because as we've mentioned above, while the broadcast industry is full of specs and standards for delivery of video over cable, and engineers both write the specs and measure the end product against those specs (every reel of most of our Belden cables, for example, is individually sweep-tested), the consumer industry has no equivalent. If you want to twist six enameled coat-hanger wires together, stick RCA plugs on the ends, and sell it as a component video cable, no one will stop you (in fact, if the audiophile market is any indicator, you might just wind up with a small cadre of devoted customers). While obviously nobody does exactly that, Chinese cable in general is notorious for being out-of-spec, even on the most crtitical measures. A 2005 PC World Magazine test of various consumer-market component video video cables found that while all were said to be 75 ohm impedance cables, the measured impedance ranged anywhere from 63 to 86 ohms; compare that with Belden 1694A, which has a conservative impedance tolerance spec of 1.5 ohms (i.e., a range of 73.5 to 76.5 ohms), and which, in actual practice, rarely is off by more than half an ohm from the specified 75 ohm impedance.
Broadcast-quality cables have published specs; we publish the specs for our cables on our own site, and in the cases where these are Belden "stock" cables, the spec documents are available at Belden's website also. What's more, these specs aren't just wishful thinking; the products are tested during and after manufacture for compliance with the published specs, and because these products are marketed to professionals who will use them to the very limits of their performance, if Belden were to fall down on the job of maintaining compliance with those specs it would suffer immediate and serious customer-relations problems with its best and most loyal customers. Contrast that with the cheap Chinese cables; they rarely come with published specs, and even when they do, there's no assurance that there is ongoing testing to verify that the cable actually meets its specs.
The important thing to remember here is that few cable characteristics are "all-or-nothing." All video cables will be described as 75 ohms; but that doesn't make all nominal 75 ohm cables equivalent, because all of them vary from that ideal spec, and the best of them vary much, much less than the worst. All video cables, likewise, are shielded; but some shielding configurations are more effective than others. We occasionally hear someone say: "but their video cable is 75 ohms, and shielded, just like yours!" Yes, but there is a very good reason why an engineer who needs the cable to meet impedance specs and perform in a high-noise environment uses ours, not theirs.
How much will issues like that matter in a particular application? Well, it depends. It depends on the equipment involved; it depends on the resolutions being run; it depends on the lengths of the cables; and it can even depend on, ultimately, some amount of subjective judgment. Some issues, like shield effectiveness, will depend on the environment in which the cable is being run; immunity from RFI doesn't matter much if you're a hundred miles from the nearest radio station, is critical if you live across the street from a TV transmitter, and for most of us, is somewhere in between those extremes. As a result, although it's clear that broadcast-quality cable will consistently outperform inexpensive Chinese-made cable in objective terms, it's not possible to categorically state that broadcast-quality cable will always provide significantly better video or audio quality; sometimes the difference will be minimal, and sometimes it will be enormous.
But even when there is reason to suppose that something less will be "good enough," there are good reasons to opt for broadcast quality. There is a great deal of security, and a sort of finality, in installing the very best cable money can buy. When the cable in your walls, or in back of your equipment rack, is the best cable in the world, there's no need to worry about it. When there is a signal quality problem (and who, in the history of home theater, has NOT had one of those crop up?), there's no need to ask whether inferior cable might be at the heart of the issue. When your component video cable is sweep-tested to a hundred times the bandwidth of 1080i component, there's no need to worry whether it's capable of handling 1080p component, at double the 1080i bandwidth--or, for that matter, any resolution you'll ever want to put through it. When your cables have the highest shield effectiveness in the industry, there's no need to wonder whether you need better shielding to combat interference. And there is economy of both time and money, as many of us have learned the hard way from time to time, in buying the best product once, rather than trying a few along the way before settling on the best.