12
Resonant Surfaces and Objects
All of the surfaces and objects in your room are
subject to the frequencies generated by your
system. Much like an instrument, they will vibrate
and “carry on” in syncopation with the music, and
contribute in a negative way to the music. Ringing,
boominess, and even brightness can occur simply
because they are “singing along” with your music.
Resonant Cavities
Small alcoves or closet type areas in your room can
be chambers that create their own “standing waves”
and can drum their own “one note” sounds.
Clap your hands. Can you hear an instant echo
respond back? You have near-field reflections.
Stomp your foot. Can you hear a “boom”? You
have standing waves or large panel resonances
such as a poorly supported wall. Put your head in a
small cavity area and talk loudly. Hear a booming?
You’ve just experienced a cavity resonance.
RuLeS oF thumB
Hard vs. Soft Surfaces
If the front or back wall of your listening room
is soft, it might benefit you to have a hard or
reflective wall in opposition. The ceiling and floor
should follow the same basic guideline as well.
However, the side walls should be roughly the
same in order to deliver a focused image.
This rule suggests that a little reflection is good.
As a matter of fact, some rooms can be so “over
damped” with carpeting, drapes and sound
absorbers that the music system can sound dull and
lifeless. On the other hand, rooms can be so hard
that the system can sound like a gymnasium with
too much reflection and brightness. The point is
that balance is the optimum environment.
Breakup Objects
Objects with complex shapes, such as
bookshelves, cabinetry and multiple shaped walls
can help break up those sonic gremlins and diffuse
any dominant frequencies.
DIPoLAR SPeAkeRS AND YouR Room
MartinLogan electrostatic loudspeakers are known
as dipolar radiators. This means that they produce
sound from both their fronts and their backs.
Consequently, musical information is reflected by
the wall behind them and may arrive, either in or
out of step, with the information produced by the
front of the speaker.
The low frequencies can either be enhanced or
nulled by the position from the front wall. Your
EM-
ESL
’s have been designed to be placed two
to three feet from the front wall (the wall in front
of the listening position) to obtain the best results;
however, your room may see things differently. So
listening to the difference of the bass response as a
result of the changes in distance from the front wall
can allow you to get the best combination of depth
of bass and tonal balance.
Now that you know about reflective surfaces and
resonant objects, you can see how the midrange
and high frequencies can be affected. The timing
of the initial wave as it radiates to your ears, and
then the reflected information as it arrives at your
ears later in time, can result in confusion of the
precious timing information that carries the clues
to imaging. Consequently the result is blurred
imaging and excessive brightness. Soft walls,
curtains, wall hangings, or sound dampeners (your
dealer can give you good information here) can
be effective if these negative conditions occur.
SoLID FootING
After living and experimenting with your EM-
ESL
speakers, you may want to expose the ETC
(energy transfer coupler) Spikes (see figure 6).
With the use of these spikes, the EM-
ESL
will
become more firmly planted on the floor and,
