Getting The Most From Your Subwoofer
10
Positioning your Subwoofer
The positioning of your subwoofer will affect the quality
of its performance. For example, locating the subwoofer
near the wall will increase bass response. If the
subwoofer is incorrectly placed it can sound "boomy",
especially if it is too near a corner. It is worth
experimenting with speaker positioning and controls (as
explained in previous sections) to find the best balance of
bass quantity and quality. A "boomy" sound delivers
particular bass notes in the musical scale unexpectedly
louder than others.
Variable Notch Filter Setup
If, after experimenting with the subwoofer position, you
feel you still have a “boomy” sound then the notch filter
will be able to attenuate the particular bass note, or
frequency, where the “boom” occurs. You will need to
use the supplied EQ Test CD, containing 11 special test
tones. One of these tones should highlight the “boom”
you are hearing. We recommend the accurate
measurement of the test tones using an SPL meter, rather
than just listening to the tones, though this can be
attempted as follows:
If you can clearly hear one tone on the CD to be much
louder than the others, the following steps can be taken.
Run the CD test tones to check for any loud problem
tones. After locating the loudest problem tone, repeat on
the CD and using a combination of the notch filter ‘cut’
and the ‘frequency’ control tune out the problem
frequency, so that it matches as closely as possible the
sound level of the adjacent test tone tracks.
Understandably, a much more accurate adjustment can
be acheived with an SPL meter, which can be purchased
from a good electrical store. To do so, follow the
instructions below:
1) Position your subwoofer in its intended location (as
discussed above), ensuring the notch filter is set to the
OFF Position. Diconnect all other speakers in your
system.
2) The SPL meter weighting should be set to
C–weighted and the response time set to slow (if
applicable).
3) The supplied test CD contains a reference tone, plus
11 modulated tones, each covering a narrow
frequency range. These values correspond to those in
the table provided.
