| Cinema Cynergy January 2002
Basic Cabling for a Home-Theater System
 Does the cabling in your home theater look
anything like this? If so, you could benefit from a few simple cabling techniques.
Clean up your act
Most home-theater systems are comprised of at least one DVD
player, VCR, A/V receiver, five speakers and a subwoofer, and a television. All of these
components require connection to the system, meaning lots of cables. If you are
using a separate processor and a multichannel power amplifier or the analog outputs of a
multichannel SACD or DVD-A player, there will be additional sets of interconnects for each
of those components too.
Compare this to a simple audio system, which would require
only one set of interconnects for a CD player and a digital interconnect if an outboard
DAC is used, another set of interconnects for a separate preamplifier and power amplifier,
and a pair of speaker cables.
Keeping your cables organized is a simple, but effective,
way to make connecting and disconnecting components from your system a less frustrating
and more efficient process. One easy technique is to label all of your cables at both
ends. This will enable you to quickly identify which components you are dealing with just
by looking at the ends of the cables.  Tara Labs has a new line of
reasonably priced cables (starting at only $10 for 1m interconnects!) with interlocking
color-coded collars that come with adhesive labels.
You can buy labels that are either preprinted or that can
be written on, but I simply use masking tape and a ballpoint pen to label all of my cables
to keep costs down. With all of your cables properly labeled (don’t forget the power
cords), you will no longer have to hunt around to identify them each time you want to
remove or replace a component. It may seem like a chore to have to label all your cables
in this manner, but it will be worth it when the time comes to start swapping cables.
Humming along
Most home-theater systems will be connected to the
television’s cable feed, which can cause grounding problems and create a humming or
buzzing noise. To solve this problem, you will need a "ground breaker."  Mondial Designs (now a division of Klipsch) sells a high-quality version of
this device called the MAGIC (Mondial Antenna Ground Isolation Circuit), which will also
protect your gear from power surges such as those from lightning strikes. The MAGIC
retails for $99.95, but you can purchase a basic unit without surge protection for about
$10 at most good audio shops.
Which way ohm?
Coaxial digital interconnects (the kind with RCA
connectors) and composite video cables are functionally the same and should consist of
75-ohm wire and connectors and as such can be used interchangeably. Although these types
of cables are all supposed to have an impedance of 75 ohms, they sometimes do not.
Purchasing these cables from a reputable cable manufacturer will maximize the chances that
you will be getting a true 75-ohm cable. Whatever you do, do not use regular stereo
interconnects to transmit either video or digital audio signals. The world will not come
to an end, but the quality of your video picture or digital signal will be degraded.
I have found that coaxial digital cables generally sound
better than TosLink optical cables. There may be times when you are forced to use TosLink
connections, if for instance your digital satellite box only has an optical output.
However, whenever possible, you should try to use coaxial digital connections for top
performance.
 Speaking of speaker wire
Spade termination provides the tightest and most secure
connection for speaker cables. However, for those of us who interchange our speakers
frequently, banana plugs make a lot of sense. One thing to keep in mind when choosing to
use spades is that they will not fit into the spring clips found on some budget components
or even some binding posts such as those sometimes found on receivers or amplifiers.
Spades also come in different sizes, which are not always compatible with all binding
posts.
Banana plugs can usually be made to fit into spring clips,
but may not fit into some binding posts or other connectors such as BFAs (British
Federation of Audio connectors). If all else fails, remember that you can use bare wire.
Bare wire actually reduces the number of interfaces that the signal must travel through to
get to the speaker, so theoretically it should make a good link as long as enough of the
wire contacts the surface of the connector.
Although purchasing speaker wire can be an expensive
proposition (especially for a home-theater system), try to avoid using 20- or 22-gauge zip
cord. As a minimum, you should try to use heavy-duty 12-or 14-gauge speaker wire, which
would become especially important if you are using it for long runs, as would normally be
the case with surround speakers.
I can see clearly now
Not much can beat the picture of a progressive-scan DVD
player and a compatible high-quality monitor connected with component video cables. If
you’re not using progressive-scan devices, the picture quality through component
video cables will still be better than that of an S-video cable, but the difference
will not be nearly as noticeable. S-video will in turn be better than that of a composite
cable. Note that these differences may be barely noticeable on an average 27"
monitor, but they will become more apparent when displayed on larger, higher-quality
display devices.
I like to use S-video cables throughout my video system
because of their picture quality, convenience, and economy. Component video cables are
expensive and cumbersome to use because they consist of three interconnects. They must be
of high quality to have the required bandwidth to carry the high-frequency signals of
progressive-scan video and are thus usually quite expensive. Remember too that most
receivers and surround processors will not allow you to use different types of video
connections between the sources and the video monitor.
Most receivers and surround processors will not output
their onscreen displays through their component video outputs. An additional consideration
is that receivers and processors will degrade the picture quality slightly when used as
video switchers, if they even have the capability. The degree of this degradation will
depend on the quality of the video-switching circuitry in the component as well as the
quality of the video cables. A direct video connection to your television monitor is the
best option, but you should make sure that routing the video signals through your
processor or receiver does not result in a noticeable loss of picture quality.
A high-value component video cable like the Sonic Horizon Sunrise will set you back a cool
$59.95.
|
If you want the very best or if you have progressive-scan
capability, then component video cables are for you, otherwise S-video makes a good
alternative.
One last thing
Although it may be tempting and easy to do, it is not
advisable to watch videotapes on your VCR through the cable antenna connection of your
television’s tuner. Transmitting both audio and video through this F-type coaxial
cable between your TV and VCR is the worst possible way to watch a video. The picture
quality will be poor and prone to interference and the sound will be adequate at best. Do
yourself a favor and connect a set of stereo interconnects and a composite video cable (or
an S-video cable if your VCR has it) either directly to your television or through your
receiver or surround processor to get the best possible picture and sound.
...Roger Kanno
roger@hometheatersound.com |
