Speaker Cables and Interconnects for your Home Theater
John E. Johnson | Secrets of Home Theater and High Fidelity
Selecting cables for your home theater system is an important task, and there are lots of choices out there in terms of the type of cables and their connectors. Besides this article, you should do a little research on various websites before you spend your hard earned money.
By John E. Johnson, Jr. Editor-in-Chief
Out of all audio and video components we buy, perhaps the most misunderstood, and underestimated, are the cables we connect them all together with. I mean, after all, they are just wires, right? Well, not so fast.
The cable serves one basic function: to carry the electrical signal (audio or video) from one component to the next component, such as from your DVD player to your receiver. Well, the wheels of your automobile carry you from one place to the next, but what if one of those tires had loose bolts that attach it to the axle? Suppose the rubber on the tire were not very good quality? How safe would you feel in getting from point A to point B?
The same thing occurs when we connect that DVD player to our receiver. If the plug is not firmly in the jack, or if the materials the cable are made of are not good quality, the electrical signal may not be quite the same when it reaches the receiver.
What about that plastic bag of cables that came in the box with the DVD player?
When we get that new CD player, DVD player, or receiver home from the store, there is most always a plastic bag of cables for us to connect things to that product. Are they good enough? The answer is that they are good enough to use until you can go to the electronics store and get quality cables or order them over the Internet. If you already have good cables, then just throw that bag away, because they might work at first, but the construction quality is so low, they will likely break down in short order.
So what constitutes a good cable?
Ah, this is a question that is debated daily on just about any audio or video forum on the Internet. There are two camps:
If you have never shopped for cables, you are in for a shock. There are some mighty high priced cables out there. You can spend - are you sitting down? - $15,000 for a set of speaker cables, and I am not talking about 20 miles of cable, I am talking one pair of cables 8 feet long!
Are they worth such a price? To some audio aficionados out there, yes. To most of us, no.
What makes them cost so much? Usually, such cables are hand made, and will have very complex arrangements of the conductors that could be solid silver. The connectors are usually very heavy. They are also made in very small quantities, and are a prestige item.
OK, so what about the rest of us? For 99% of us consumers, we don't need to spend all that much to get great cables. There are many companies out there who manufacture such cables, and they don't cost an arm and a leg. They do cost more than that plastic bag of cables that came with your DVD player, but think of it this way: Your car cost you thousands of dollars. Do you want to drive it on a good road or one full of pot holes? The same is with our home theater system. We spent thousands of dollars for the DVD player, the receiver, the speakers, and the display (TV or projector). We should make sure we carry the signal around from component to component with good conductors and connectors.
One rule of thumb is to spend 10% of your home theater budget on the cables. So, if your system only cost you $1,000, then $100 worth of cables would be appropriate. If your system cost $10,000, then spend $1,000 on the cables. My opinion on this is to just get some good cables to begin with, and then you can use them with whatever system you upgrade to a couple of years down the road.
A good cable has a solid feel to it, especially where the conductors are attached to the plug. The insulator will be made of foamed plastic, such as polyethylene, or Teflon, and the plug will be slightly tight when you push it into the jack. The plug will be larger than the ones on the cables in that plastic bag.
How do I choose?
This will be the tough part. Even before the Internet, there were a lot of cable manufacturers, but now, there are even more. The good news is that so much competition has kept the prices affordable, and also, you can see what they look like, as well as order them at custom lengths, while at your computer desk. Of course, you can also go into dealers' showrooms, or visit your local mass market electronics store, and buy them there. Monster Cable is a brand that most of us are familiar with. They seem to be everywhere. And, they are good quality. But, as with any product, you should evaluate several choices before making a decision.
Some manufacturers sell their cables primarily at dealers. These brands include Accell, Analysis Plus, AudioQuest, GutWire, Harmonic Technology, KimberKable, Monster Cable, Nordost, Slinkylinks, Straight Wire, UltraLink, and WireWorld. You can find a list of dealers on many of the cable company's websites.
There are also a lot of cable manufacturers who sell their products on the Internet, either just on their own websites, or on various websites that supply other brands too. These include AViC, BetterCables, Blue Jeans Cable, CablesToGo, Cobalt Cable, Pacific Cable, River Cable, and Ultralink.
In general, the companies who sell primarily through dealers are the ones with the complex conductor arrangements. And, they are generally more expensive. The Internet cable companies generally get their products from an OEM (Original Equipment Manufacturer) supplier, who makes them for that company as per specific design specifications, with a custom logo printed on them. They represent a tremendous value because (1) dealer markup is avoided; and (2) there is no brick and mortar store overhead to pay for.
So, if you like the idea of really fancy engineering going into your cable design, then look at the websites for those companies to locate a dealer near you, and go shopping. For those who desire basic, but good quality cables, buying them over the Internet from one of the on-line cable stores is a great deal. Not only are they very affordable, but they are excellent quality, and you can order them at specific lengths.
Types of Connectors
When shopping for cables, you need to select the connectors that will be at the end of the cables. These are also called the terminations.
For interconnects, which connect a DVD player or Satellite TV tuner - also called a set top box or STB - to your receiver, or a preamplifier to a power amplifier, the terminations will be one of the following: (1) RCA plugs; (2) BNC plugs; or (3) XLR balanced plugs.
The RCA plug is the most common type of connector. It looks like this:
In this case, there are three RCA plugs because this is what's called Component Video Cables. The three cables carry red, green, and blue color information from a DVD player to a projector. This particular set of cables is from Blue Jeans Cable. Individually, this cable is called an RCA coaxial cable or RCA coaxial interconnect.
The RCA plugs in the photo above are good, but basic quality. You can buy cables with more sturdy - and more expensive - plugs. Some even come as right angles so you can get them connected when the back of the receiver is near the rear cabinet wall. A photo of a right angle RCA plug, from Accell, is shown below.
When we first began playing our movies with DVD players instead of VCRs some years ago, we used one RCA interconnect, called composite video, to send the video signal to our TVs. There was also an S-Video connector on the back of the DVD players, but many of us did not have TVs with S-Video input jacks. That was unfortunate, because S-Video gives a much better video signal than composite video.
Here is a photo of an S-Video extension cable, from Pacific Cable. Notice that it has four conductors (you can see four pins in the S-Video plug on the left). Two carry the color signal (chroma), and two carry the brightness (luminance). Keeping the two signals separate lets the TV do a better job of creating the image on the screen. If you buy an S-Video cable, it will most likely be a male/male cable rather than the male/female cable (which is an extension cable) shown in the photo.
So, the order of image quality from lowest to highest, is composite video, S-Video, and then component video. All modern DVD players have component video outputs, but your TV may not have component video input jacks. In that case, use S-Video if you can. For those of you updating to a new TV and DVD player, you should consider digital connections, which include DVI and HDMI, referred to later in this article.
For most applications, you will be connecting a pair of RCA coaxial interconnects to carry a stereo audio signal. The exception would be when you want to connect the digital audio output of a DVD player or satellite box to your receiver. This requires one cable, and when it is an RCA coaxial interconnect, it MUST have a 75 Ohm impedance. You cannot just use any old RCA interconnect for this purpose. So, when shopping for a digital coaxial cable, be sure it is labeled as such, not labeled simply as an audio cable.
The alternative to using a digital coaxial interconnect is to use a Toslink optical digital cable. Here is what the connector looks like.
The end of the Toslink cable has a fiber optic tip, and it must be inserted a certain way because the end is flat on one side, and the corresponding socket is also flat on one side. This particular Toslink cable is from Monster Cable.
The second type of connector for interconnects is the BNC. This is usually a 75 Ohm cable and can carry analog or digital audio or video signals. They are a little more expensive than RCA, but provide a much sturdier connection. A photo of the end of the BNC connector is shown below.
Most receivers have RCA jacks on the rear panel, while the high-end surround sound processors and receivers may have a set of BNC jacks. Digital projectors for home theater also may have BNC. They hold tighter than RCA and should be used if you have a choice.
If you want to use RCA cables and your projector has BNC jacks, you can buy RCA-BNC adapter plugs for about $2.50 each. You connect the RCA plug of your cable on one end and the other end is a BNC plug that you can then connect to your projector. A photo is shown below.
The photo also shows the locking ring on the BNC connector. You push it into the jack and twist it to lock.
The third type of connector for interconnect cables is the XLR or balanced connector. While the RCA and BNC connectors have two conductors - one hot and one ground - the XLR connector has three, two of which are hot and one is the ground. The balanced connection cancels noise that is common to the two hot conductors. Here is what they look like from Harmonic Technology.
On the left is an XLR connector, and an RCA connector is shown on the right for size comparison. Notice that the XLR has three pin sockets. The other end of the cable will have three pins. XLR cables are designed so that the signal will be directed from the pin connector to the socket connector. An XLR output on a processor will have the pins, while an XLR input on a power amplifier will have the pin sockets. An RCA cable, on the other hand, usually has a pin on both ends, i.e., RCA plugs, and the RCA inputs and outputs of various components will primarily be RCA jacks (sockets).
During the past couple of years, two more digital interconnect cables have emerged. One is DVI and the other is HDMI. These cables are used for carrying digital video from DVD players and satellite boxes to your TV or projector. They have many conductors. DVI connectors carry only digital video, while HDMI carries both digital video and digital audio signals.
Here is what a DVI connector looks like. Since DVI cables come in several types, make sure you are getting the one you need. For example, this is a DVI male/female extension cable. You may need the cable to be male on both ends. Check the DVI junctions on your equipment to see what you should purchase. Also, DVI comes as single link and dual link. We have found that DVI-D single link cables usually are the ones that work properly.
More recently, HDMI cables are taking over for DVI cables. They look a bit like USB cables (photo shown below).
The DVI and HDMI cables shown in the two photos are from Pacific Cable.
Speaker cables have a choice of terminations too. These consist of banana plugs, pins, and spades (sometimes just a bare wire is used).
The banana plug is the easiest to use. Here they are on a pair of River Cable speaker cables.
The blue arrow points out the banana plug, while the green arrow points out an interesting feature of this particular plug. It locks to the speaker banana jack (usually on the rear panel of most speakers). You loosen the connector by turning the locking ring pointed out by the red arrow. Then insert the banana plug, and then tighten it by turning the locking ring in the other direction. This is very nice because it keeps the banana plug from coming out of the speaker binding post.
A simpler, but also tight connection, approach to banana plugs is shown below, from Nordost. The banana plug is a very stiff spring that is easy to insert, but holds very tight, and this is important. These particular cables are flat, which makes them convenient to put under a rug so you can reach the rear surround speakers and hide the cables.
Perhaps the most common type of banana plug is shown below, with this example being from BetterCables. It uses a simple spring mechanism to hold the plug in position.
Pin connectors are not as common, but are an alternative. They let you slide the pin into a small hole in the speaker binding posts, and you then tighten the post which locks the pin into place. This example is from Accell Cables.
The last type of speaker cable termination is the spade. Here is a photo.
The spade looks like a two-pronged fork. You place the spade over the speaker binding post center and then tighten the binding post knob to lock the spade in place. This is the sturdiest way of connecting speakers. However, you need to make sure the spades are not too big or too small for your particular speaker binding posts. Notice again that these particular speaker cables, from Analysis Plus, are flat, so they can go easily under a rug.
Selecting cables for your home theater system is an important task, and there are lots of choices out there in terms of the type of cables and their connectors. Besides this article, you should do a little research on various websites before you spend your hard earned money. As with any type of product, you can go inexpensive up to very expensive, but there are nice products out there at all price levels.
John E. Johnson, Jr. Editor-in-Chief Secrets of Home Theater and High Fidelity www.hometheaterhifi.com
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