How do I know which cables to use

The cable selection at the electronics store could be renamed
the "wall of confusion." Not only are there dozens of
different kinds of audio/video cable -- some for stereos,
some for home theaters, some for HDTVs and some for … who the
heck knows? Even if you're lucky enough to find the cable you
need, you still have to decide between super expensive and
suspiciously cheap.

And then there's the salesman. "Have you heard of
silver-plated connectors?" What? "If you're buying speaker
wire, then you should also buy these stands that keep the
wire from touching the floor." Why? "The more expensive the
cable, the better the sound." Really?

In this article, we're going to give it to you straight.
We'll explain, in simple terms, what each type of audio/video
cable does and where it should be used. Along the way, we'll
debunk some cable myths, starting with the idea that the most
expensive cable is the best.

Audio Cables

Let's start with audio-only cables. The most common audio
cables are called analog RCA cables. These are the cables
with red and white, or sometimes red and black connectors.
RCA cables are widely used to connect devices like VCRs and
DVD players to TV sets or CD players to stereo receivers.
RCA audio cables come in pairs with two connectors on each
end, a red one for right stereo and a white (or black)
connector for left stereo. They are often bundled with video
cables. Experts recommend gold-plated RCA connectors for
extra protection against corrosion, especially if you live
in a humid environment.

The other most common type of audio cable is speaker wire.
Speaker wire runs from a stereo receiver to all speakers
except the subwoofer (that requires a coaxial cable).
Each speaker needs its own dedicated wire. Speakers not only
receive audio signals via speaker wire, but also power.

Speaker wire is made from 99 percent oxygen-free copper and
usually comes "unshielded," which means you can see the
copper conductor. Speaker wire comes in different thicknesses
or gauges rated from 12 to 18 (thickest to thinnest). As
a general rule, the longer your speaker wire, the thicker
the gauge you should use. For speaker wire lengths up to
20 feet (6.1 meters) long, 14-gauge is sufficient, but
anything longer than 60 feet (18.3 meters) requires 12-gauge
wire.

Speaker wire is fairly simple, so you can get away with
buying inexpensive, bulk wire. And don't let anyone tell you
that all of the speaker wires in your system need to be the
same length. That's a myth.

Most audio recordings are digital nowadays, and there are
several newer cables that specialize in carrying
high-bandwidth digital audio signals. Optical digital cable
(also known as fiber-optic and Toslink) transmits audio
signals as pulses of light and is impervious to interference
[source: ecoustics.com]. Another digital audio cable is
called digital coaxial. It looks the old coaxial cables that
connect satellite dishes or cable TV signals to televisions,
except this is specially designed to carry digital audio.
You'll find optical and digital coaxial jacks on newer DVD
players, CD players and stereo receivers.

The last type of audio-only cable is called analog
multi-channel cable. This cable is designed for use with
special players such as DVD-audio that play discs recorded at
high sample rates for the maximum sound quality. Analog
multi-channel cable consists of six to eight bundled RCA
connectors, each responsible for a different audio channel on
the back of a stereo receiver.

In the next post we'll talk about video-only cables, and
Audio/Video vables, a slightly more complicated topic.