Subwoofer Placement Guide - BLUE SKY EXO User Manual

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
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Stereo Monitoring System
USER MANUAL • 9 • Subwoofer Placement Guide
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.