MartinLogan Montis, User Manual

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Room Acoustics 27
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CoustICs
Your Room
This is one of those areas that requires both a little background
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. This com-
ponent is a very large variable and 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 participates 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 system can literally generate all of the infor-
mation required to recreate a musical event in time, space, and
tonal balance. Ideally, your room should not contribute to that
information. However, every room contributes to the sound to
some degree. Fortunately MartinLogan had designed the Montis
to minimize these anomalies
Let’s talk about a few important terms before we begin.
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 domi-
nant dimensions is 10 feet. Large objects in the room such as
cabinetry or furniture can help to minimize this potential prob-
lem. Some serious “audiophiles” will literally build a special
room with no parallel walls just to help eliminate this phenom-
enon.
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 frequen-
cies 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 syncopa-
tion 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 on the floor.
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. Can you 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 envi-
ronment.
Breakup Objects
Objects with complex shapes, such as bookshelves, cabinetry
and multiple shaped walls can help break up those sonic grem-
lins and diffuse any dominant frequencies.
Solid Coupling
Your loudspeaker system generates frequency vibrations or
waves into the room. This is how it creates sound. These vibra-
tions vary from 20 per second to 20,000 per second. If your
speaker system is not securely planted on the floor or solid sur-
face, it can shake as it produces sound and, consequently, the
sound can be compromised. If your speaker is sitting on the car-
pet and only foot gliders are used, the bass can be ill defined
and even boomy. The use of spikes is recommended to insure
secured footing for your speakers. (See ‘Solid Footing’ for spike
information and installation instructions).
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