Specifications

M&K Sales Training Outline
page 13
May 98
http://www.mksound.com
Advantages of multiple
subwoofers
Whenever possible, we recommend using two (or more) subwoof-
ers in any system. A second subwoofer significantly improves a
system's total bass output, dynamic range, and headroom. The sec-
ond unit doubles the amount of driver radiating area, which, depend-
ing on room placement, increases efficiency as much as 3 dB (the
same as doubling the amplifier's power). The second subwoofer then
doubles available amplifier power for another 3 dB of output for a
total increase of 6 dB!
The addition of a second woofer means that both woofers have to
work up to 6 dB less hard (25% of the work) for a given output level,
making for lower distortion (due to less cone motion) at all but the
highest playback levels (which are much higher with the second
woofer).
You'll remember that the bass quality and peaks and dips in the
frequency response of a subwoofer in a given room are dependent on
the location of the subwoofer. If you can find and use the optimum
location for a subwoofer in a room, two subwoofers at that single loca-
tion is best!
If the optimum location cannot be used, two subwoofers in different
locations can complement each other. From two locations, different
room modes are "driven", which can produce a smoother response in
the room. Listening and measurement tests can help determine the
best dual subwoofer placement. The use of stereo subwoofers is con-
trolled by the same conditions.
Recently, some questions have arisen regarding the use of multiple
subwoofers in 5.1 channel Dolby Digital and DTS systems. Often
overlooked in these discussions is the fact that 5.1 channel control-
lers and receivers include what is called Bass Management. This
allows the user to route the bass content of each channel either to the
main speaker reproducing that channel or to the subwoofer(s).
This means that a single subwoofer can reproduce the output of all
5.1 channels (just as a single subwoofer in a stereo system repro-
duces the bass content of the left and right channels). Whether a
system has two channels or five channels, the Satellite-Subwoofer
concept means that one subwoofer can always handle the output of
all channels. Of course, multiple subwoofers are always better (see
above).
We strongly recommend that the bass content of all channels
be fed to all subwoofers in a system. Never send just the LFE
channel to a subwoofer.
Multiple subwoofers in
5.1 channel systems
Using Multiple Subwoofers