Stereo Monitoring System
USER MANUAL • 9 • Subwoofer Placement Guide
Page 10 • User Manual • Subwoofer Placement Guide
The low frequency response and efficiency of a subwoofer are heavily
influenced by the acoustics of the playback environment. More specifically,
the response is influenced by the room’s dimensional ratios, types of
construction and location of the subwoofer within that environment. You
can significantly improve the subwoofer’s in-room response and efficiency
by experimenting with various room placements until you find an optimum
location.
When placing the subwoofer there are several general guidelines that should
be kept in mind. These include:
•
Every acoustic space is unique and experimentation is an
important key in finding the best possible location in your
particular environment.
•
A subwoofer becomes more acoustically efficient (has greater
output) as you move it closer to a room surface (e.g. wall or
floor).
•
A subwoofer will give maximum output and maximum acoustic
excitement when it is located in a corner.
•
Under certain acoustic conditions corner locations are optimum;
in others they can excite multiple “room modes”, producing
“muddy” or “boomy” sound.
The following methods have been found to work successfully under most
conditions:
The first method described below doesn’t require any special test
equipment. It does require a pair of good ears and familiar broad-spectrum
music material – recordings with lots of energy across a wide frequency
range (from low to high). The recordings should be highly dynamic and be
of relatively high quality.
The second subwoofer placement method requires using a real time
analyzer – such as those made by Gold Line™ or The Audio Toolbox(TM)
by TerraSonde(TM). Although many home audio enthusiasts may not have
access to this equipment, if you are having a sound system or home
theatre system professionally installed, this information may be useful to
the installer.
Method 1
Place the subwoofer at the main listening position and connect
and make sure it is properly connected to your receiver. Turn
on the CD or music source and make sure that the level of the
subwoofer has been raised high enough so that low frequencies
are not masked by the background noise in the room. Once you
have roughly balanced the level, between the subwoofer and main
speakers, move around the room and pay careful attention to
where the spectral response is smoothest and has the greatest
low frequency extension, pay special attention to the corners
and along the walls. Also, make sure to pay attention to where
the system has its’ greatest impact and definition. You are not
just listening for the most boom, but rather where the bass is
most accurate and natural sounding. Remember, because the
subwoofer is basically omni-directional, the best spot for the
subwoofer can be next to, or even behind, the main monitoring
area.
After finding the spot where the subwoofer has the best response
in the room, place the subwoofer in that location. Now, listen
from the main position and confirm that the subwoofers response
is similar to when the positions were reversed. If it is, then leave
the subwoofer in that location. If not, continue to experiment with
the subwoofer location until the most accurate and best response
has been achieved.
Method 2
Subwoofer placement using a real time analyzer – Such as those made by
Gold Line™ or The Audio Toolbox™ by TerraSonde™.
Place the subwoofer at the main listening position and connect the
subwoofer to your pink noise generator. Turn on your pink noise
generator and make sure that the level of the subwoofer has
been raised high enough so that low frequencies are not masked
by the background noise in the room. Now set the analyzer to
1/12 octave resolution (or whichever setting provides the highest
resolution on your particular analyzer), real time mode and begin
to take measurements around the room. If the analyzer you are
using has the ability to do real time averaging, then use this
function to better analyze the spectral response.
As you walk around the room, be sure to pay careful attention to
where the spectral response is smoothest and has the greatest
low frequency extension, pay special attention to the corners and
along the walls. Remember, because the subwoofer is basically
omni-directional, the best spot for the subwoofer can be next to,
or even behind, the main monitoring area.
After analysing the data and finding the spot where the subwoofer
has the best response in the room, place the subwoofer in that
location. Now, take some additional measurements from the
listening position and confirm that the subwoofers response is
similar to when the positions were reversed. If it is, then leave the
subwoofer in that location. If not, continue to experiment with the
subwoofer location until the smoothest and best response has
been achieved.
Additional Notes
It has been found that a subwoofers’ in-room response can sometimes be
improved by facing the drivers toward a wall. Again, experimentation is the
key to finding the best possible location.
Properly designed subwoofers generate tremendous energy, so
they may vibrate objects close to them. If you hear buzzing or
vibrating objects, make sure to try and dampen those objects.
Rattling, buzzing and other sympathetic resonances can make
the subwoofer localizable and therefore should be avoided. Using
a sine wave generator can be helpful in locating these acoustic
anomalies.
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