R2SUBZ and R2SUBDF - Installation Guide - Page 6
likely to occur. If the wall or corner location is too far away from the full-range loudspeaker(s), it may result in the
R2SUB being drastically out of time sync with one or more of the full-range speakers. Sometimes the sound quality of
a wall or corner placement is not desirable, simply due to the room’s acoustical properties. Keep in mind that when
wall and corner locations are appropriate for use, they offer a tremendous increase in power output; however, they
may not always be the best choice.
It’s a good idea to experiment with different locations by conducting listening tests before finalizing the
installation.
Figure 1
(2)
Keeping the subwoofer(s) as close as possible to the mid and high loudspeaker(s) will decrease phase irregularities and
time smear. If the subwoofer(s) is placed too far away from the mid/high loudspeaker(s), the listener will experience a
disjointed character to the program material, causing the musicality of the system to suffer.
(3)
Although the R2SUB is not highly directional, its acoustical output follows the inverse square law. That is, every time
the distance from the R2SUB to the listener is doubled, the output level will decrease by 6dB. When covering a large
space with multiple R2SUB’s, it may be of benefit to space them some distance apart from one another to even out the
levels throughout the space (typically, this would be done if the mid/high loudspeakers are also spaced apart from one
another, such as in a distributed stadium system). Although spacing will help maintain an even level throughout the
listening space, there may be some areas in between two or more subwoofers that experience a certain amount of
power subtraction caused by destructive interference. Destructive interference occurs when waveforms meet and are
partially or wholly out of phase with each other due to unequal path lengths.
Conversely, if multiple R2SUB’s are located directly adjacent to one another, their power output will add together,
almost seamlessly. This is known as constructive acoustic addition.
Polarity
The correct polarity of the R2SUB subwoofer is a function of its placement in relation to the full-range loudspeaker(s) it will
be used with. This is known as the Phase Relationship of the two systems, though Absolute Phase also plays a role which
will be discussed later.
Depending on the placement of the R2SUB in relation to the full-range loudspeaker(s), as well as the selected crossover
point, the optimal response of the system might be obtained by reversing the phase of either the subwoofer or the full-
range loudspeaker(s). The easiest way to determine the proper phase relationship is to excite the system with a test signal
(such as pink noise) and to view the resultant response on an audio spectrum analyzer. If such equipment is not available,
it is also possible to determine the best phase relationship by careful listening.
