Final Placement; Your Room; Terminology - MartinLogan Preface User Manual

detailed and articulate yet not bright and piercing, pianos
should have a nice transient characteristic and deep tonal
registers. This will give you clues on how to get closer to
these ideal virtues.

Final Placement

After the full break in period, obtaining good wall treat-
ments, and the proper toe-in angle, begin to experiment
with the distance from the wall behind the speakers. Move
your speaker slightly forward into the room. What hap-
pened to the bass response? What happened to the
imaging? If the imaging is more open and spacious and
the bass response is tightened, that is a superior posi-
tion. Move the speakers back six inches from the initial
setup position and again listen to the imaging and bass
response. There will be a position where you will have pin-
point imaging and good bass response. That position is
the point of the optimal placement from the front wall.
Now experiment with placing the speakers farther apart.
As the speakers are positioned farther apart, listen again,
not so much for bass response but for stage width and
good pinpoint focusing. Your ideal listening position and
speaker position will be determined by:
• Tightness and extension of bass response
• Width of the stage
• Pinpoint focusing of imaging
Once you have determined the best of all three of these
considerations, you will have your best speaker location.

Your Room

This is one of those areas that requires both a little back-
ground to understand and some time and experimentation
to obtain the best performance from your system.
Your room is actually a component and an important part
of your system. It can dramatically add to, or subtract
from, a great musical experience.
All sound is composed of waves. Each note has its own
wave size, with the lower bass notes literally encompassing
from 10' feet to as much as 40' feet. Your room partici-
pates in this wave experience like a three dimensional pool
with waves reflecting and becoming enhanced depending
on the size of the room and the types of surfaces in the room.
Remember, your audio system can literally generate all of
the information required to recreate a musical event in time,
space, and tonal balance. Ideally, your room should not
contribute to that information. However, every room does con-
tribute to the sound to some degree. Fortunately MartinLogan
had designed the Preface to minimize these anomalies

Terminology

Standing .Waves
The parallel walls in your room will reinforce certain notes
to the point that they will sound louder than the rest of
the audio spectrum and cause "one note bass", "boomy
bass" or "bloated bass" . For instance, 100Hz represents a
10 feet wavelength. Your room will reinforce that specific
frequency if one of the dominant dimensions is 10 feet.
Large objects in the room such as cabinetry or furniture
can help to minimize this potential problem. Some serious
"audiophiles" will literally build a special room with no
parallel walls just to help eliminate this phenomenon.
Reflective .Surfaces .(near-field .reflections)
The hard surfaces of your room, particularly if close to your
speaker system, will reflect some waves back into the room
over and over again, confusing the clarity and imaging of
your system. The smaller sound waves are mostly affected
here, and occur in the mid and high frequencies. This is
where voice and frequencies as high as the cymbals occur.
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.
Placement & Room Acoustics 7