Taking the Mystery Out of Wiring and Cables

Kimberlee WattNews

Network Picture


If you’ve ever hooked up a stereo , surround sound or whole-house system you’ve heard lots of techno-babble. “Thicker wire! Thinner wire! Wire made from macaroni, or is that made by Marconi?”–you name it, there’s a special cable or connection this week that blows away last week’s Last Word. That is, until next week. The days of doorbell wire, alligator clips and electrical tape are long gone, along with simplicity. Mixed blessing. Let’s clear the air a bit.

Wiring 101

How and with what your home is connected will make a difference in both performance and long-term satisfaction. The first and most important step in wiring is planning. Even if you buy the exotic cable of the week, the key is still planning the infrastructure.

Have you ever been annoyed by having the TV or speakers in exactly the wrong spot because there’s no connection where you need it? That’s expensive and time-consuming to change after everything is buttoned up. By use an accurate, scaled floor plan or at least a good drawing of your home to plan ahead for seating, listening, viewing and control. Coordinate this with your electrical wiring plan to have power where you want it. Although a lot of AV gear is wireless, we still can’t broadcast power.

Take time to note where you’ll want central control and equipment, where you do and don’t want sound or picture, who will be using the system and how techie they are. Are you interested in integrating entertainment with lighting and other functions such as motorized window treatments, security and internet? This is the time to do it. Ask your home integrator for help with this, as they’ve seen it all and can help you avoid unpleasant surprises. You can avoid many last-minute or, worse yet, after-finish problems by thinking ahead.

Centralizing wiring makes installation and operation more logical, useful and flexible for later changes or additions. “Structured cabling a must” means pulling all the wiring starfish-style to one spot in the home. Good home integration specialists will label every cable at the central term and destination, which makes for fewer problems down the road. Terminating all cables in a central box or work panel makes it possible to hide amplifiers and “black boxes” of all sorts where you don’t have to look at them, a plus for your d├ęcor. The cabling can then be placed in-wall and invisibly distributed to each room.

Understanding your wiring choices

Let’s focus on the sound and picture, as the differences in performance are easily demonstrable. Long cable runs from a centralized location make wire quality important. All cables conduct electrical signals or power from one point to another, but the cable itself changes what comes out the other end.

All wire has resistance to moving electrons, as well as other characteristics which affect your system, such as capacitance, impedance and inductance. The longer the wire, the more these produce noticeable signal degradation, power loss and eventual replacement.

Signal is transmitted largely on the surface of each strand of wire, which is also where corrosion occurs, remember that copper oxidizes. Cable made of large numbers of very fine strands conduct the signal better as it has much more surface area than cable of the same gauge made up of fewer, larger strands. The unfortunate side effect is surface oxidization, (remember that copper oxidizes, think of the Statue of Liberty or copper roofing) which ages the cable and changes the signal dramatically, reducing quality and enjoyment, eventually causing a need to replace the cable.

Copper begins with a fair amount of oxygen, but quality cables use Oxygen-Free Copper,
lowering and slowing oxidation for longer lifespan and better performance. Better cable manufacturers such as Snap AV and Straight Wire have known this for a long time and produce cabling which delivers more of the signal without changing it.

Exotic and more expensive metals do not necessarily improve performance. Gold looks great and is very marketable but gold is not as useful a conductor as either copper or silver, although it has the advantage of resistance to corrosion. Gold cable terminators are certainly pretty, but the ultra-thin plating rubs off the connecting surfaces after a few uses, leaving the connecting surface bare. Gold is fine but neither the last word nor as good as it looks. Physical integrity of cables and connectors is more important and actually more expensive to build. Durability beats flash.

In audio applications, these things change sound by dulling or muddying highs, making transients such as drum- or key-strokes less impactful and even lowering amplifier control of bass in a speaker.

In video the effects show up in color inaccuracy, grainy images, shadow bars on the image and other annoyances. Video signals are higher frequency and more complex than audio signals, and as such are more sensitive to wiring issues. Much of that has been eliminated with digital TV’s HDMI cables and connections. An often ignored but real problem with HDMI connectors is their tendency to disconnect easily, making them prey to active kids, vacuum cleaners and pets. HDMI interconnects with locking connectors avoid this and are available from better home integrators. Once a custom system has been installed to minimize visible cabling it can be harder to access an accidentally disconnected cable, so ask your integrator or installer what connections are being used.

Other types of cables

Shielded coaxial video and cable TV wiring looks much as it has for years, but there are differences which aren’t immediately apparent. Very old-style shielded cable, called RG59, is more flexible than its successor, RG6 due to its less robust shielding and lighter casing material, both of which mean higher susceptibility to outside interference and physical wear. Cable companies usually refuse to be responsible for house wiring done with RG59. For digital cable and satellite signals the heavier and better-shielded QuadShield looks almost the same but works far better. Again, ask your installer what is being used.

For internet and internal digital signals the old standard CAT5 cable is being replaced by the more effective and signal-accurate CAT6 and CAT7. If you’re building or remodeling ask for those and in most rooms it is a good idea to wire for at least two terminations for future use. The baby’s room may not need an internet connection right now, but not for long.

Outdoor speakers have improved greatly and now justify something better than just twin-lead wires. If you’re putting faux rock speakers in the yard or by the pool specify direct-burial cable, which is resistant to water damage and heat. If possible, always run them in conduit for longer life.

Planning ahead is the most important part of all, as we mentioned. “Future-proof” is a convenient buzzword but there is really no such thing (who predicted the Internet in 1960?). You can however anticipate and avoid many pitfalls by working with your integrator and pre-wiring for the future or at least facilitating later cable runs by running conduit for future expansion of your home’s electrical and A/V systems.