| The
Art and
Science
of Audio
System
Tuning:
Part
Three |
| Commentary |
| Mike
Vans
Evers |
| June
2000 |
All
Audio
Electronics =
Superset

Note:
Areas 1-6 are
subsets of the super
set: All Audio
Equipment.
Area
1
A.P.T.:
This stands for
Asymptotic Pure
Tonality and is a
goal for both
systems and
components. (Please
note: This is not
necessarily THE
goal, but it is
definitely A goal.)
Once a
product/system has
achieved exceptional
levels of measured
performance (a high
degree of static
neutrality) as well
as an evenly
balanced resonance
response (a high
degree of dynamic
neutrality), its
tonality will
approach that of
real life. However,
nothing man-made is
perfect, and we will
always be
approaching, but
never reaching, the
"Pure
Tonality" of
real life. (The
definition of an
"asymptote"
is a straight line
that continually
gets closer and
closer to a line
with an infinitely
extended curvature,
but never intersects
it.)
Area
2
High
Degree of Static
Neutrality: There
are numerous tests
and measurements
based upon sine and
square waves:
distortion, phase
shift, frequency
response, slew rate,
dispersion,
signal-to-noise-ratio,
and other
measurements such as
rise time. These
tests are
representative of
conventional
thinking on the
possible distortion
mechanisms of audio
components. For a
system/component to
occupy this subset
of the larger set
"Accurate,"
most conventional
tests must be passed
at the highest
levels possible.
Area
3
High
Degree of Dynamic
Neutrality: An even
distribution of
low-Q resonances,
with few
irregularities, is
required for an
audio system or
component to reside
in this subset of
the set
"Musical."
At the present time,
the test methodology
relies on the human
ear/brain
combination.
Area
4
"Accurate":
Systems and
components that
measure well in at
least a few of the
many conventional
measurements reside
in this group.
Area
5
"Musical":
Systems and
components that have
a pleasant sound,
rather than an
"analytical"
sound, reside here.
Area
6
Not
Musical & Not
Accurate: Plastic
clock radios, many
boom boxes, and some
rack systems.
It
will not be possible
to predict true
sonic comparability
between components
from a
manufacturer's
"spec
sheets," until
a component's
resonance response
is MEASURABLE and is
utilized as an
everyday design tool
by all audio
equipment
manufacturers. Why?
Because this readily
audible but as yet
unmeasurable
quantity is always
AS significant as
the conventional
quantities that are
measurable
(distortion,
frequency response,
output impedance,
etc.) In fact, a
component's
resonance response
is quite often MORE
sonically
significant than any
conventional
quantity. Why?
Because, as higher
and higher levels of
static neutrality
are achieved, there
will be less and
less to cover up the
sonic influences due
to resonances (and
other little
understood
phenomena). An audio
system's resonance
response has become
much more audibly
significant than
vanishingly small
levels of
distortion.
A
Tone Balancing
Rationale
Products
used to change the
sound of an audio
system, even though
they aren't actually
IN the accepted
audio signal path,
are often called
"tweaks."
When you
"tweak" an
audio system, you
are actually
"tone
balancing" it.
The physical nature
of every tone
balancing /tuning
product (tweak)
mandates that the
resonance response
of any system it is
used with must
change; if it is to
be put on, around,
under, or over a
piece of audio
equipment, IT HAS TO
CHANGE the RESONANT
SIGNATURE of the
SYSTEM. Because the
resonances have
changed, the
tonality and
therefore the sound
of the system must
also change.
Resonance
balancing is a skill
that you can learn.
The first step is to
trust your ears. You
know what you like.
The available
arsenal for making
your system sound
better is really
quite formidable.
Cones, pucks, dots,
oils, bricks,
platforms, and a
host of other tuning
products are readily
obtainable. A
suitable selection
should become a part
of your audio
toolbox. Care should
be exercised,
however: just as no
one wrench can turn
every bolt, no one
tuning product can
fix all sonic
problems. Tone
balancing products
are tools that are
handy when it and
the problem match
up; otherwise they
just take up space.
There are no bad
tools, just
inappropriate ones.
Cones
bricks, dots, pucks,
jackets, discs,
isolation platforms,
etc. all change the
resonant energy in
audio components and
accessories. These
changes directly
influence the
harmonic balance and
imaging of your
audio system,
thereby affecting
your perspective on
the music.
Tone
balancing an audio
system is like
taking a saw, or
other tool, to a
piece of wood. The
basic engineering of
the wood is already
done for you. All
you have to do is to
make it fit your own
particular
situation. The sound
of your audio system
is like that piece
of wood.
Why
Would I Want to Tone
Balance My System?
While
most audio companies
have achieved a high
degree of Static
Neutrality through
use of conventional
tests like THD and
frequency response,
other elements that
are major
contributors to
dissonance have been
overlooked until now
and can cause a lack
of synergy between
high-tech
components.
Non-signal-path
products are the
main focus of this
article because
their use will
significantly alter
the resonance
response and thus
the harmonic balance
of your audio
system. While
signal-path products
also alter the
resonance response,
they usually cost
considerably more
than most tone
balancing products.
This makes learning
how to balance your
system a cost
effective approach
for achieving
musical
satisfaction.
By
learning some simple
balancing
techniques,
audiophiles will be
able to: 1. Realize
high quality sound
without wasting
thousands of
dollars. 2.
Eliminate the
frustrations caused
from buying a
"latest and
greatest"
product that isn't
so great after all
(at least for
you...it may be for
someone else). 3.
Bridge the gap
between now and the
time when a
product's
measurements ARE an
accurate guide to
its compatibility
with the rest of
your system.
It
is not necessary to
completely
understand or
believe in these
techniques in order
to begin using them.
Don't be afraid to
experiment. These
changes will be far
easier to undo than
trying to get back
the old amp that
your new amp was
SUPPOSED to trash.
In
addition to these
practical
considerations,
there is also this
artistic
consideration:
Pictures
taken from slightly
different angles or
offset in small
increments of time
will sometimes
portray vast
differences in
meaning. In the same
way, the sound of
most musical
artists' material
will vary from
performance to
performance. In
part, this results
from the artistic
interplay between
the various
musicians (as well
as from varying
acoustics and sound
reinforcement
elements). This
artistic interplay
is the wellspring
from which emotion
and meaning are
communicated to the
audience. Because
each artist brings a
new perspective to
each performance
(sometimes the
change is subtle,
sometimes not), his
ability to
communicate with the
other band members
and with the
audience also
changes on a
day-to-day
basis...sometimes
for the better,
sometimes for the
worse.
Occasionally,
it is refreshing to
be able to achieve a
new perspective on a
piece of music that
is very well known.
With the balancing
methods outlined in
this article,
changes can readily
be made to an audio
system's sonic
perspective that
will enable the
listener to derive
new enjoyment from
an "old
friend." This
is also an instance
of artistic
interplay and, as
such, is as valid as
any other aspect in
the production and
reproduction of
recorded music.
After all, this
manipulation of
perspective is the
stock-in-trade of
recording, mixing,
and mastering
engineers the world
over.
What
Is Tone Balancing?
Tone
Balancing is
tweaking with a
twist; it is an
approach that
focuses on the audio
system rather than
the component or the
tweak; it is the
antithesis of the
standard operating
procedure. The
hot-new-whatever
will sonically help
some systems a
little, and help
some systems quite a
bit. However, the
hot-new-whatever
will sonically HURT
some systems a
little, and
significantly hurt
other systems.
Tone
Balancing is the
author's term for a
system of techniques
and a rationale that
came about because
audio components and
systems were seldom,
if ever, sonically
neutral. When
balancing a system,
i.e. adding and
subtracting
resonances, you are
changing the
system's tonality
and harmonic
balance...as well as
its imaging
specificity and
sound staging
capabilities.
Tonality is the
starting point for
all sonic qualities.
The-sound-of-an-audio-system-playing-a-piece-of-music
is a sonic-portrait
of that piece of
music. The canvas
for this music is
your listening room,
its acoustics create
a sonic-canvas, and
the harmonic balance
of the system
creates a tone
painting on your
sonic canvas. The
tweakable nature of
an audio system
provides a great
opportunity for you,
the listener, to
achieve a more
musical perspective
through this process
of adding and
subtracting the
right resonances for
your system. This
process is called
tone balancing.
Tone
Balancing Your
System
OUR
GOAL: to increase
our enjoyment level
when listening to
music. Our means are
the application of
Axioms 1 and 2.
Envision
a three-legged table
with a bowling ball
balanced on its top.
The bowling ball
represents musical
enjoyment. By
keeping the ball at
its highest level,
i.e., off the floor,
we achieve the
maximum level of
enjoyment with our
system. The three
legs represent the
three major factors
we have to balance
in order to keep the
tabletop level and
the bowling ball off
the floor.
These
three major factors
are as follows:
-
The
Room
Acousticians
design recording
studios utilizing
scientific
principles which
allow them to design
OUT many of the
flaws that most of
us have to live with
in our listening
rooms. Standing
waves (room
resonances) are an
unavoidable
consequence of
having a roof,
walls, and a floor.
The dimensions of
your listening room
determine the
distribution of its
standing waves.
Because most of our
listening rooms
aren't designed by
acousticians, our
standing wave (room
resonance)
distribution will
probably in no way
resemble the ideal.
Because
of this, the
listening room is a
MAJOR factor in the
sound of our
systems. The same
system will sound
different in
different rooms.
Just ask any
died-in-the-wool
audiophile who has
moved. Equipment
resonances that
complemented the
previous room's
resonance modes
often conflict in
the new room. In
addition, power in
different cities, or
even different parts
of the same city,
cannot sound exactly
the same. (See
Appendix E.)
2.
The Static
Neutrality of the
Components
The
equipment we buy
should utilize the
highest level of
engineering and
technology that we
can afford. It's
true that superior
specifications have
not always been a
key factor in the
best sounding
equipment. However,
superior measured
(static) neutrality
can be sonically
obscured by an
irritating resonance
response. (It's
always best to
compare apples to
apples. For example,
don't compare
single-ended tube
amp harmonic
distortion
specifications with
those from a
conventional solid
state amp and expect
to draw a valid
conclusion.)
3.
The Dynamic
Neutrality of the
System
There
are thousands of
manufacturers, brand
names, and models of
equipment;
consequently, there
are billions of
possible
combinations. The
manufacturer that
designed the
equipment, the
reviewer who wrote
about it for your
favorite magazine
and your dealer ALL
have different
systems. Each of
these systems will
sound different.
Each system's owner
will feel that he
has THE correct idea
about the sound of
any given piece of
equipment. However,
your room, your mix
of equipment,
stands, cables, etc.
WILL be different.
If a particular
piece of equipment
makes the resonance
response of your
SYSTEM more even,
you will probably
like it. If not, you
probably won't. This
is because your ear
will be drawn to the
colorations caused
by a more uneven
resonance response,
distracting you from
enjoying the music.
(Tone-balancing the
system in order to
even out the
resonance response
irregularities can
often cure these
distractions. This
will increase the
system's level of
Dynamic Neutrality,
produce a more
pleasant
sonic-portrait, and
increase your level
of enjoyment.)
Tone
Balancing the Bass
Response of the
System
Overview
"The
whole is greater
than the sum of its
parts" is a
phrase that can be
used to describe an
in-tune audio
system's bass
response.
It
is important to note
that our focus is
the bass response of
the system, rather
than the bass of any
one component. This
is called a
"systems
approach". Even
though we will be
working with only
one component at a
time, we are
interested only in
how well its bass
integrates with the
bass of the SYSTEM.
Individual
components by
themselves cannot
make sound, much
less music.
It
is usually best to
get the bass as even
as possible before
tuning the midrange
and the treble.
While the following
methods of tone
balancing the bass
also affect both the
midrange and the
highs, for this
step, we should only
be paying attention
to how they affect
the bass.
[However,
if the highs are
brash and annoying,
it might be best to
first tame the highs
to at least a minor
degree, by one of
several methods: 1)
Place heavy or
dampening-type
objects (rubber
pucks, MDF or Teak
blocks, sand or
lead-shot filled
bags, a phone book,
etc.) on top of
front-end
components. 2)
Remove metal type
spikes or cones from
under components,
one component at a
time, until the
highs are more
balanced. 3) Fill
lightweight metal
equipment stands
with playground-sand
(available from home
improvement or other
such stores) so as
to dampen the upper
harmonics of the
stand's resonance
response.]
There
are 3 elements
involved in tuning
the bass response:
1.
The frequency
response of the
speaker
How
low it goes and how
flat it is in the
bass region.
2.
The energy storage
of the room
Standing
waves are
unavoidable. Very
few listening rooms
are designed by
acousticians.
Because of this, you
will almost
certainly experience
an uneven bass
response at your
listening position,
even with perfect
speakers.
3.
The energy storage
of the equipment
and cables
Mechanical
resonances are also
unavoidable. The
weight of the
component together
with the spring-like
rubber feet forms an
energy storage
mechanism
(resonance). This
mechanical energy
storage affects the
electrical
properties of the
wire in the
equipment, thus
affecting its sound.
The directionality
of the power cords
and connecting
cables in your
system also play an
important factor in
the smoothness of
the bass response of
your system.
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