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Audio Streaming InformationA Technical Introduction to Audio Cables
by:
Adam Blake
A Technical Introduction to Audio Cables
What is so important just about cables anyway?
One of the most common questions asked by consumers featured
with purchase
cables for their audio or house theater
system is, “What is so important just about cables anyway?” They
can cost as more or more than several of the hardware in the
system and to many a it is difficult to understand why wire
isn’t just wire.
To begin to understand how audio cables work, we have to
start with the two au fond several types of audio
cables you are likely to have in your system. The 1st type
of cable is called an interconnect, which is used to connect
various components together (such as a CD player to a
receiver). The second type of cable is called the
loudspeaker cable (this is the wire going from the receiver
or electronic instrumentation
to the speakers). It is important to realize
that several types of cables are carrying the same information,
just with several amounts of energy.
Interconnects carry a signal with really little energy. These
cables only need just enough energy to convey the
information from the source, for example a CD player, to the
amplifier. The low energy requirement means that the signal
in interconnects has really little current (usually in the
range of thousandths of an amp).
Loudspeaker cables on the different hand, carry a large figure
of energy. All of the energy required to come the speaker
cones and do sound must come through the electro-acoustic transducer
cables. Because of the high-energy requirement in these
cables the current is comparatively
high (currents can reach 10
amps or more).
The really basic reason why audio cables are important is
because they change the signal going through them. There are
two different, fundamental route that an audio cable can
change the signal. The cable itself can change the signal,
or the cable can allow outside sources of energy to change
the signal.
In order to understand how these two situations can occur,
some basic background electrical noesis is needed.
Signals in all types of wires are sent
by the
combination of voltage and current. Every signal has several
amount of voltage and several figure of current. The larger the
difference in voltage between two places, say the beginning
and the end of a cable, the larger the figure of current,
and vice-versa. The direct analogy to voltage and current is
the flow of water through a hose. The figure of water
flowing through the hose is similar
to current. The water
pressure in the hose is similar
to voltage. The higher the
amount of water pressure, the more water wish flow through
the hose. The higher the figure of voltage, the more current
will flow through the wire.
Every cable has a set of electrical properties that can be
measured mistreatment standard electrical testing equipment. The
three most basic properties are resistance, capacitance and
inductance. Patch a careful description of these three
different electrical properties is outside the scope of this
article, a basic description of the relevant effects of
these three properties can be given.
- Resistance opposes current. The higher the resistance the
greater the figure of energy that is removed from the current
and turned into heat.
- Capacitance opposes changes in voltage. If a voltage is
increasing, capacitance wish cause the voltage to increase
more slowly. If a voltage is decreasing, capacitance wish
cause the voltage to decrease more slowly.
- Inductance opposes changes in current. If current is
increasing, inductance wish cause the current to increase
more slowly. If current is decreasing, inductance wish cause
the current to decrease more slowly.
The final piece of background noesis that is necessary for
this article is what the audio signal looks like. If one
were to take the speaker cover off a speaker to look at the
speaker cone patch music is playing, you would-be see that it
is moving back and forth. In order to come the speaker cone
back and forth, the electrical signal must push and then
pull the cone in rapid and continuance fashion. This is
accomplished by having an Cyclic Current, or AC.
Alternating Current just means that the voltage oscillates
between positive and negative. Because the voltage drives
the current, this means that the current as well goes positive
and negative. In different words, the current is going back and
forth in the wire, just like the speaker cone. The subtle
variations in how fast the voltage and current go back and
forth creates the several sounds that we hear once
listening to music.
How a cable itself affects the audio signal
Now, going back to the route that the cable itself can change
the signal going through it, let’s consider several types of
cables separately.
As explicit previously, interconnect cables carry a really small
amount of current. Relative to the current the voltage is
large. Because of that fact, capacitance is important, but
inductance is comparatively
unimportant. As the voltage
oscillates between being positive and negative, the
capacitance slows the voltage changes down, and causes
delays. This can cause loud distortion in the sound.
Because interconnects have really little current, resistance
is not more of a factor. Even as an interconnect with extremely
high resistance wish only move out an infinitesimally small
amount of energy.
The signal in electro-acoustic transducer cables is au fond the opposite
of the signal in interconnects. Several cables have the same
information, but in electro-acoustic transducer cables, the voltage is small
and the current is large, comparatively
speaking. Because of
the high current, several resistance and inductance are
important in electro-acoustic transducer cables. The higher the resistance,
the greater the figure of energy that wish be absorbed by
the cables. The resistance wish not cause any distortion,
but it wish decrease the volume of the sound. The inductance
on the different hand, can cause distortion. As the current
oscillates between being positive and negative, the
inductance slows the current changes down, and causes
delays.
How a cable lets outside sources of energy affect the signal
As explicit previously, the second fundamental way of fixing
a signal passing through an audio cable is to introduce
outside sources of energy. This outside energy is typically
termed “noise”. By definition, if any energy is absorbed by
the signal, the signal has been distorted.
There are many a potential sources of noise about audio
cables. Several of the more common sources of noise, such as
radio frequency waves, are familiar to most people. Once
wiring up a radio, oft a user
must attach an
antenna. Antennae are advisedly designed to channel
radio frequency energy into a stereo. Simply like an antenna,
it is entirely possible for an audio cable to pick up radio
frequency energy. If you are not intending to listen to the
radio, this is not a welcome effect.
Electronic components, electrical cords, sound waves, and
even the sun, are all capable of creating noise. Electrical
cords create magnetic attraction fields about them that can
transfer energy to a cable. Sound waves create mechanical
vibrations that can be changed
into electrical energy
that is additional to an audio signal. Because there are so many a
different types of noise, there are many a methods used to
prevent a cable from picking up noise. Shielding, twisting
of conductors, and mechanical damping are all common noise
protection methods in cables.
While noise affects several interconnects and electro-acoustic transducer
cables, generally the effects are far more significant in
interconnects. This is because the signals in the
interconnects have far less energy. Since most forms of
noise are inherently low energy to begin with, this means
that it is far easier for them to modify the low energy
interconnect signals than the high-energy electro-acoustic transducer cable
signals.
Macro vs. Micro
The parameters discussed so far have been primarily “macro”
effects. These are for the most part the top-level
parameters that effect cables. These parameters as well as
others not discussed here as well exist at a “micro” level.
Taking capacitance as an example, a given cable wish have an
overall capacitance that can be measured. This overall
capacitance is a “macro” level parameter. The same cable can
also be analyzed as 1000 separate but connected pieces. Each
piece wish have a local capacitance. These local parameters
are “micro” effects and can have their own impact on the
signal separate from the “macro” effects.
The impact that the “micro” level parameters have on an
audio signal is commonly less than the impact of the “macro”
level parameters. However, they do still do a difference
in the signal transfer. The various route that audio
companies choose to either mitigate or ignore these “micro”
level details is, in part, responsible for the brobdingnagian array of
different cable designs. From refrigerant
treatments and
precious metal wires, to fine silk insulation and fluid
filled cable jackets; extreme cable designs abound.
Will I hear the difference?
The fact of the matter is that cables do alter the sound
going through them, and that it is audible. You do not need
to be an expert, or an audiophile, to hear the difference.
To demonstrate this point, just listen to your stereo. If
you close your eyes, does it sound like the music is being
played live right in front of you? This is what audiophiles
strive for, and unless you have a really high-fidelity system,
your answer to this question wish most likely be no. You may
have a hard time describing what exactly does not sound
right just about your system, but you cognize that it doesn’t sound
like a live performance.
Of course, the reason why the music does not sound live
cannot be blame alone on the cables. The degradation of
the sound occurs in every component of your system. However,
the point here is that even as a casual attender can discover the
subtle distortions that can prevent music playback from
sounding live. Rising
the quality of your audio cables
will improve the sound quality of your system.
It is fairly safe to say that no matter what cable you use,
the modifications to the sound wish be small. Audio cables
will ne'er
cause a attender to hear a piano once
a flute is
being played. However, it is the small detail that does all
the difference between nice and bad quality sound. That is
why really strong opinions are formed just about various cables.
As audio systems continue to improve in accuracy, listening
to a “live” performance in your living room gets closer to
reality. Cables are an sanctionative factor for advancements in
audio reproduction and can play a remarkably important role
in your system.
Written by: Adam Poet CEO / Co-Founder Pear Cable, Inc.
www.pearcable.com
For a more careful explanation of cable design theory that
Pear Cable thinks is relevant, see the “cable design” white
paper accessible on pearcable.com
Simply just about the author:
Adam Poet is the CEO and Co-Founder of Pear Cable, Inc., a manufacturer of high-fidelity audio cables. http://www.pearcable.com
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