Baffled by all the techno-babble, or just wanting to check what the real differences between cable types are? Well, here's the place to find some answers. We've kept it as jargon free as possible, or explained ourselves in plain English where jargon really is necessary. All entries have been listed in alphabetical order for your convenience...
The traditional electrical signal of video or audio, based on frequency information as opposed to data bits (or bitstream) as used in digital. There is a myth amongst many that analogue signals are more prone to interferences than digital, but both are electrical signals which can be subject to external (environmental) or internal (within the cable) distortions, which is why very high quality cables are advantageous for both.
Short for "American Wire Gauge". This is a worldwide standard for measuring the thickness of a wire or cable. The smaller the number, the larger the cable. A reduction of 3 AWG represents a doubling of the overall thickness of a carrier, and vice versa - eg a 12AWG cable is twice as thick as a 15AWG cable.
The data flow of a digital signal, transmitted either by light (optical) or electricity (coaxial). The signal is made up of millions of bits of data with each as a "1" or "O". Interferences can cause a changing of polarity of some data bits, which will in turn alter the end result, even if in a subtle way.
The ability of a cable's dielectric or insulation to store electrical energy. The lower the number, the better - see also Dielectric Constant.
In video cables, high capacitance will cause additional interferences in the signal as the dielectric absorbs some energy from the conductor, only to release it again milliseconds later, essentially adding it to a latter part of the signal (where it shouldn't be!!).
In audio cables, high capacitance will result in an attenuation (or tapering off) of the lower frequencies, which is bad! Remember that the main component in your loudspeakers' crossover that restricts bass frequencies from going to the tweeters is a capacitor. High capacitance in line audio cables and speaker cables can have a similar effect as a small capacitor in the crossover.
The color component of an analogue video signal, usually designated with the letter "C". Transmitted parallel to the Luminance ("Y") signal in S-Video and Component Video, and combined in the same carrier in a Composite video cable.
- Coaxial Cable
A type of cable construction which sees the center conductor housed within a circular dielectric (see "dielectric" further below) and wrapped with a shielding material, usually copper and/or mylar foil. The impedance of a coaxial cable is determined by the relative sizes of the core and dielectric - the thicker the dielectric in relation to the core, the lower the impedance.
75ohm coaxial cable is used for both analogue video and coaxial digital audio signals. Analogue audio is less affected by impedance, and is more concerned with other specifications like resistance.
- Coaxial Digital
The method of transmitting a digital data bitstream using an electrical signal (as opposed to optical). The construction of a caoxial digital cable requires the same principles as an analogue video cable, hence they are generally interchangeable. Some believe that coax digital cables differ in some respects, but they don't really (both 75ohm, both benefit from low capacitance and resistance, good shielding etc).
Coaxial digital is the preferred connection over the common plastic type TOSlink optical cables, due to the greater bandwidth and electrical grounding of coax. However TOSlink is a serious contender when you start to look at the true glass fiber cables, as these offer significantly more bandwidth with less errors, when compared to the plastic variety.
- Component video
A very popular type of analogue video connection with enough bandwidth to carry a High Definition video signal. It comprises a Luminance channel ("Y" - green plug) and two separate Chrominance ("C", red and blue plugs) channels. The Luminance is essentially the same as that in S-Video; ie - the black and white picture info.
The difference is that Component Video keeps the color info more accurate than S-Video by keeping the colors separate - Cr for Red and Cb for blue. The sum of these two colors is then subtracted from the whole by your display device, and the difference is inserted as green. This is why Component video is sometimes called "Color Difference". Not to be confused with RGB (even though the plugs are red, green and blue). RGB is entirely different again...
- *** Did you know? *** The picture information on a DVD is stored in Component Video format, hence for your DVD player this is a preferred method of connection over RGB.
- Composite Video
The lowest quality form of direct video connection. It is a combination, or "composite" of all picture elements. Composite is one step below S-Video, but the difference between the two is very noticeable. If you have a choice to use S-Video instead of composite then do so, but if you have no other option then a superior quality Composite Video cable will still enable you to make the most of the available signal.
The ability of a material to transmit electrical energy efficiently. In an interconnect cable, high conductivity is essential in passing the signal cleanly and quickly. The relative conductivity of various metals is shown below (the higher the number, the better);
- Silver - 106
- Annealed Copper - 100
- Gold - 65
- Pure Iron - 17
- Nickel - 16
- Tin - 13
- Steel - 7
This table clearly shows that silver is the best of conductors, followed by copper. See also 'Skin Effect' further below in the Glossary to see why either Pure Silver or Pure annelaed copper offers the best value for audio cables, but Silver plated copper is best for video cables.
In the context of a cable, the dielectric is the material which surrounds the core of a coaxial cable, separating it from the shield. However the use of the word 'dielectric' in a cable is somewhat of a misnomer because a good quality cable will use a 'dielectric' material which is intended to store as little energy as possible. Technically speaking however, a dielectric is designed to store energy, not minimze it!
Think of a capacitor, which is an electrical component whose primary job it is to store energy. The bit inside that does the storing is called - one guess... - a dielectric. The amount of energy it can store is quoted as 'capacitance'. Makes sense, doesn't it? In a cable, using a dielectric material which stores too much energy will increase capacitance in the cable, which in turn causes all sorts of problems with the signal, resulting in distortion and overall reduced performance.
All coaxial-based cables featured on Cinema Cables use Nitrogen Injected Polyethylene (it's a mouthful to say, but it's good stuff!). This produces the lowest capacitance of all dielectric materials, even lower than Teflon. The result? - the best possible overall performance.
- Dielectric Constant
The dielectric constant is a relative value which represents the ability of a material to hold charge, or hold capacitance. As mentioned above in the Capacitance definition, the holding of charge is undesirable in AV cables. The lower the dielectric constant, the better. The dielectric constants of some common AV cables materials are as follows, in order from best to lowest;
- Polyethylene - Nitrogen Injected - 1.5
- Polypropylene - 1.6
- Teflon - 2.0
- Polyethylene - solid - 2.2
- Polyvinyl Chloride (PVC) - 2.4
As can be clearly seen, Nitrogen Injected Polyethylene is the best material to use as a dielectric - much better than Teflon. All KORDZ cables featured on CinemaCables.com use this material, chosen for it's no-compromise performnace.
The method of storing data in numerical terms. For both video and audio signals, the digital storing of data sees information reduced to a collection of billions of "1"s and "0"s. Digital has the great benefits of far greater bandwidth than analogue, resulting in more information and superior dynamics. It also allows multiple datastreams through one cable, without cross-interferences.
The analogue equivalent stores the information as frequencies. Both analogue and digital are subject to interferences and anomolies both inside the cable and from the environment surrounding it, and should only be trasmitted through the highest quality cables as practically available.
Short for "Digital Video Interface". This interconnect was developed as a multimedia interface for the transmission of High Definition video signals in the digital domain. Available in "Single Link" with a max bandwidth of 4.95Gbps (1280x1024 @80Hz), or "Dual Link" with a bandwidth of 9.9Gbps (1920x1080 @80Hz). Single link cables are easily identified by the two-row gap in the block of pins, whereas dual link has all pins present.
DVI can also be used for analogue transmissions. These cables are called DVI-I (as opposed to full digital DVI-D), commonly available as an alternative to VGA (analogue RGB), or even as an adapter cable from DVI-I to the common 15 pin D-Sub VGA. A DVI-I cable can be identified by the presence of four additional pins, two top, two bottom, on the horizontal fin (located towards the left side of the male connector, viewed head-on). A DVI-I cable is quite different in configuration to DVI-D, and the two should not be confused.
* Note: DVI-D, whether single link or dual link, can be adapted very effectively to HDMI, although only the single link bandwidth will be passed. DVI-I cannot be adapted to HDMI.
- Dynamic Range
By definition: "the ratio of the strongest to the weakest sound intensity that can be transmitted or reproduced by an audio or broadcasting system" (Source Merriam Webster Online).
When we refer to a sound being "dynamic", we refer the speed at which it can go from quiet to loud, and vice versa, and the intensity it produces. High dynamics, as experienced with digital sound, is often referred to as sounding more 'powerful'.
Similarly, dynamics in video refers to the reltive difference between dark and light in a scene. A very dynamic picture can be seen as having intense whites, rich blacks and exceptional detail.
Today's digital sources for both audio and video are capable of producing exceptional dynamics, with the limiting factor often being the cables used to connect components. Many people are still using the same types of cables that they used for their old analogue devices, and yet expect superior results!! Superior interconnects = superior results.
Abbreviation for "Electro-Magnetic Interference". This refers to the ambient magnetic raditiation which is commonly produced by electrical appliances, the presence of which can adversely affect the electrical signal travelling through and audio or video interconnect. You can't really do much to stop EMI as such, but you can effectively shield your cables from it. To do this, only use interconnects which have a copper braid shield which covers in excess of 90%. Avoid cables with copper spirals instead of braid, or which use braids less than 90%, or even worse, no braid at all!!
IMPORTANT NOTE: A foil wrap does not shield against high frequency EMI. A foil wrap is only an effective shield against low frequency EMI and full range RFI. The combination of both types of shield in an interconnect is the most desirable combination, giving effective 100% shielding against full EMI and RFI. All KORDZ cables featured on CinemaCables.com use true 100% double shielding.
"High Definition Content Protection" is a standard which was introduced to DVI-D as a means to protect software copyright owners from digital piracy. It is a code which is contained within a digital video bitstream to block the recording/copying process. The later development of HDMI connectivity saw HDCP introduced as a standard feature.
It is important to note that HDCP refers to a buried code within the digital output of a source device, such as a DVD player or digital TV receiver. It is sometimes thought that a HDCP enabled DVI-D output requires a different cable to standard DVI-D, somehow being wider bandwidth or something of the sort, but this is not the case. The only difference is that extra piece of information which the output device is sending through the cable along with the main bitstream.
Abbreviation for "High Definition Multimedia Interface". The latest standard for HD digital sources, allowing true high bandwidth HD signals as well as eight channels of digital audio. This bi-directional BUS style cable will ultimately replace separate video and digital audio cables, producing an 'all-in-one' alternative. It differs from DVI in that it is capable of even wider bandwidth, as well as having the inclusion of the digital audio bitstream, whilst maintaining full HDCP compliance. It is however fully backwards compatible with DVI-D, allowing DVI-HDMI adapters and cables to function properly. However, DVI-I cannot be adapted to HDMI, as this would require digital/analogue conversions.
Inductance is the term given to an 'electromotive' force which is created by the travelling of a current through a cable (sorry, I couldn't really avoid this terrible jargon here!). All audio and video cables have a positive and negative carrier. The current which travels in both directions along these opposing carriers creates a type of magnetic field, the excessive presence of which can be a noticable loss of detail and high frequency information, especially in audio cables.
Remember that the main component in your loudspeakers' crossover that restricts high frequencies from going to the woofers is an inductor (conductive coil). High inductance in line audio cables and speaker cables can have a similar effect as a small inductor in the speaker's crossover.
TIP: Never coil up speaker cables or line audio cables whilst they are in use, as this amplifies the inductance of the cables. By doing so, you are creating a large inductor, much like the construction of the inductor in your speaker's crossover, which is a coil of wound copper. Instead try to purchase the correct length of interconnect, especially with your speaker cables.
Abbreviation for "Low Frequency Effects". This refers to the ".1" channel in your 5.1 or 6.1 channel digital surround sound system - ie. the subwoofer. This mono channel is low enough in frequency that it allows some flexibility on the placement of your subwoofer, due to the non-diectionality of the low bass information. A digital surround soundtrack contains some extraordinarily dynamic bass info, so a good quality, low resistance subwoofer interconnect can certainly make an enormous difference to the sub's performance.
The contrast/brightness channel of a Component Video or S-Video connection. Luminance is represented with the letter "Y" (which is most commonly seen in conjunction with the Chrominance "C", or color channel/s). S-Video comprises two channels - "Y" luminance and "C". Component Video further breaks the color info into two channels, hence being "Y" for luminance (green plug), "Cr" for red, and "Cb" for blue. If you connect just the Luminance channel of either an s-video or component video interconnect, you'll get just a high quality black and white picture.
- Mylar Coated Foil
A foil wrap shield which has an applied layer of Mylar, a conductive polyester film which permits the integration of the foil wrap and surrounding copper braid. The results are a more effective overall shield for the cable.
See also "RFI", "EMI" and "Shield -100%".
- Nitrogen Injected
In the context of Polyethylene as a dielectric, the injecting of the material with nitrogen (often referred to as "foaming"). The dielectric constant of the dielectric is greatly reduced as the thousands of tiny bubbles in the polyethylene further reduce it's ability to store energy, resulting in extremely low capacitance. The best method available to achieve this result.
Abbreviation for "Oxygen Free Copper". This is one of the most misunderstood terms in the interconnect field. Oxygen free simply refers to a copper which meets a stringent standard of processing to remove all of the naturally occuring oxygen particles. Oxygen causes copper to oxidize, much like rust with iron - a bad thing for AV interconnects, so it's removal is crucial! The percentage number often accompanying an "OFC" label actually has nothing to do with it's OFC status, but rather with the level of purity of the copper, the balance amount of which is made up of other elements (such as iron, zinc, tin etc).
EG:- "99.9998% OFC" (as per all KORDZ cables) means that it is high purity copper with only a 0.0002% component of minerals and alloys other than copper, and it has been processed to compress out all Oxygen particles from within the core, enhancing longevity.
In the context of digital audio signals, Optical refers to an interconnect which trasmits a digital bitstream by way of light, as opposed to electricity. The most commonly used optical cable in AV systems is the TOSlink fiber optic cable.
There are genreally two different types of TOSlink cables - plastic and glass. Plastic cables don't vary much. Some are better because they may have polished ends (reducing light refractions from the end of the cable), but even the best plastic fiber optic cables limit bandwidth to below that of coaxial digital audio. Glass fiber cables on the other hand offer far greater bandwidth and accuracy than any plastic cable. A premium glass cable should have finely polished ends with properly aligned terminations for best results.
The Perfect Conexxions™ cables, available here on CinemaCables.com are true galss fiber, exceeding the requirements of the most critical of tests. The difference between the two models is essentailly the level of protective wrap over the fiber, the thicker model representing less internal refractions and greater protection against excessive bending and subsequent breakage.
A type of material as commonly used in producing dielectrics or insulation in AV interconnects. Usually abbreviated to "PE", this material has a very low dielectric constant and is hence preferable to PVC. However it is not as durabe as PVC and melts very easily. For this reason it is not commonly used as the outer jacket of an interconnect - PVC is better for this. The nitrogen injected version of PE produces even better results when used as a dielectric material (see "Dielectric" and "Nitrogen Injected").
This is an important specification in an interconnect. As the name suggests, the value of resistance refers to the amount by which the signal travelling through a cable's carrier is restricted. The primary factors which affect resistance are conductor material and size. The more conductive the material, the lower the resistance; the larger the conductor, the lower the resistance.
It's sort of like a water hose. A large hose can carry more water than a small hose, as it offers less 'resistance'. Likewise an interconnect with a larger conductor can carry more current as it offers less resistance than a samller carrier.
NOTE: Don't assume that "the bigger the better" will be the case. It's true that the larger the cable, the lower the resistance, but other issues come into play. For example, larger conductors usually produce more internal inductance, which can adversely affect high frequency performance. A high quality interconnect should reflect the best overall balance of compromises between such phenomena by minimizing each effect by clever design.
Abbreviation for "Radio Frequency Interference". This refers to the ambient multitude of radio frequencies which are present in our environment, the presence of which can adversely affect the electrical signal travelling through and audio or video interconnect. You can';t do anything to stop RFI from 'floating' around you home and your system, but you can effectively shield your cables from it. To do this, only use interconnects which have a foil wrap shield. Avoid cables which offer only copper braid or spirals as shielding.
IMPORTANT: A foil wrap does not shield against high frequency EMI. A foil wrap is only an effective shield against low frequency EMI and full range RFI. The combination of both types of shield in an interconnect is the most desirable combination, giving effective 100% shielding against full EMI and RFI. All KORDZ cables featured on CinemaCables.com use true 100% double shielding.
Abbreviation for "Red, Green, Blue with Horizontal and Vertical Sync". This is a five channel interconnect which utilizes all of the fundamental components of a full analogue video signal. Red, green and blue are of course the three primary colors, and the horizontal and vertical sync channels dictate the positioning and scanning information to properly place the image on your TV/display device.
RGB can also be used as a four channel connection, whereby the horizontal and vertical syncs are combined on one channel. This is usually referred to as "RGB - Composite Sync", and is the form of RGB used in European SCART connectors.
There is also another method which places the H&V sync information in with the Green channel. This is quite obvoiusly called "RGB - sync on Green". If your system requires this form of connection, simply purchase a component video cable, as it already contains the correct number of channels with the right color coding (the signal is however vastly different).
- Shield - 100%
Please refer to "Shield - Braid" and "Shield - Mylar Foil". In brief, it's the combination of the two forms of shielding, which produces an overall shield which is 100% effective against external interferences.
- Shield - Braid
A shield wrap which comprises a braid of conductive material, most commonly copper. The tightness of this braid determines the total coverage achieved - that is a loose braid might only achieve 60% coverage, whereas a tight bradi could be 90-95%. By contrast, the alternative of a copper spiral instead of a braid usually only produces 40-60% sheilding, even if there's a fair bit of copper. A braid shield is critical in blocking low frequency EMI (see "EMI" and "Shield - 100%").
- Shield - Mylar Foil
An aluminum foil wrap which is coated in a layer of mylar, for greater conductivity. The foil wrap should be slightly overlapped at the join,. so as to eliminate leakage of interferences through potetial gaps. This shield layer is important as it blocks the harmful RFI as well as high frequency EMI (see also "RFI", "EMI" and "Shield - 100%").
- Silver Plated
A conductor (most commonly OFC) which has been coated in a thin layer of silver. In a video cable, the signal travels entirely on the surface of the conductor, so the use of silver plating ensures that the entire signal is travelling through silver, not copper (as silver is a better conductor). This is so due to the "Skin Effect" - see below. This methos is quite ingenious as it is far more cost effective than using solid silver, but effectively produces the same result.
TIP: Do not use a silver plated cable for audio applications. In an audio cable, "skin effect" is far less prevalent (in fact virtually non-existent in the lower frequencies) and so the entire cconductor is used for the signal, right down to the center of the core. Using a silver plated conductor would then make the signal travel through two different materials simultaneously, producing a somewhat confused result with compromised timing. Some people still like the sound of silver plated conductors, but it's really not ideal. I agree that silver is the best, but for audio, use either all-silver or all-copper.
- Skin Effect
Now this is an interesting one... If you can get your head around this, you'll better understand the whole concept of coaxial cables and how they carry an audio or video signal, as well as the true benefits of silver plating.
First picture what a coaxial cable looks like in cross section. It comprises a core (conductor) surrounded by a dieltric, then a layer or two of shielding, then the outer jacket. The center conductor is the Positive carrier , the shield is the Negative carrier. As an AC signal (audio or video) travels through the cable there is a magnetic field created between the core and shield. Just like in a magnet, positive and negative are drawn towards each other. A low frequency signal is affected very little by this magnetic field, but as the frequency increases, the effect of being drawn towards the surface, or "skin" of the conductor increases. This is true whether we are talking about a stranded bunch or a solid core of copper - ie it does NOT apply to each strand in a bunch, but the bunch as a whole.
Bass frequencies travel through the entire core, and as the frequency increases, the amount of the core that the signal travels through decreases (becomes thinner). Remember the audible audio range for most of us is about 30Hz-18kHz. The whole carrier is used in varying degrees for a full range audio signal. It is important for this reason that the entire carrier be consistent in material and quality in order to obtain a linear result.
On the other hand, a video signal is measured in Mhz or above. When these frequencies are transmitted, all of the signal is travelling on the extreme outer surface of the carrier. For this reason, the inner conductor has less bearing than the quality of the outer skin. This is why silver plating is beneficial for video, as it puts the silver where it is being entirley used, without spending all that extra money getting solid silver when the inner core isn't even being used! A solid core of silver plated copper also produces a smoother surface through which to conduct, as opposed to a stranded bunch where the signal may 'jump' strands.
A critical element in the production of a high quality interconnect. The solder used is often overlooked, but is really just as important than the choice of cable and plug. The signal does, after all, travel through the solder as it passes from plug to cable, then back to plug again. A high quality solder should be ultra-conductive with a clean flux core (the flux cleans the surfaces that are being bonded together, producing a superior joint).
We use only the very highest quality high content silver solder from Kester. Some have asked us about crimp or compression type joints, as opposed to soldered. These alternatives are convenient and faster to produce, but don't give the same degree of oxygen free termination as a good soldered joint. A professionally soldered joint should last at least 50 years without noticeable degradation, free from oxidization.
The speaker in an audio system which is designed to produce only bass frequencies. In the modern system the subwoofer should have it's own dedicated amplification, usually with more power than the other full range channels, in order to produce the powerful low frequency dynamics. Some powered subwoofers have a single RCA type input, in which case a mono line audio cable of low resistance should be used. If your subwoofer has a "stereo" input, try using a "Y" cable (1x RCA to 2x RCA), which can produce a sensitivity boost of up to 3dB, depending on model - ie: more volume!. (See also "LFE").
A video signal that comprises two parts, Luminance ("Y") and Chrominance ("C"). S-Video is essentially the result of combining the two chrominance channels of Component Video (the Cr & Cb channels) . That is, it's one step down from Component Video, but remains one step up from Composite Video.
The digital audio connection standard for fiber optic cables. TOSlink refers to the type of end on the cable, not the cable itself. That is, TOSlink is the name of the square plug which fits into the optical sockets on an AV receiver, amplifier or DAC. The plug can be metal or plastic, the quality of which determines the accuracy of the fit into the socket. The cable itself can be plastic or galss, as discussed in the section titled "Optical".
Short for "Video Graphics Adapter", VGA comprises a full analogue RGB signal. The most common application for VGA is a computer monitor, although many LCD and plasma displays as well as projectors also make use of this connector, as it saves valuable space over the 5x RCA jack alternative. VGA uses a 15 pin 'DB' (HD-15) type plug, with three rows of 5 pins. Only ten of the pins are used, being for red, green, blue and their respective grounds, as well as horizontal and vertical sync, and two extra ground pins.
The unique type of insulation used in the KORDZ® S-Video plugs. S-Video plugs usually offer no insulation between the four pins through which the Y & C (and their respective grounds leads) run. X-Guard™ is a Teflon cross piece which separates the four pins, giving effective insulation as well as eliminating the chance of any of the pins from shorting with each other.