Operating instructions

22THE OUTLAW’S GUIDE TO THE SMS-1
but can be adjusted in 1Hz increments from 15Hz to 120Hz to move any
channel closer to a dip or peak that needs help. Lastly, there is the Q set
-
ting. The default setting for Q is 4.3, but it can be adjusted in 0.1 increments
from 0.3 to 20.0. Q denes how wide a section of the curve is aected by
the equalizer channel. The default of 4.3 represents approximately 1/3 of
an octave, while the minimum of 0.3 represents about 3.5 octaves and the
maximum of 20 represents 1/12 of an octave. Adjusting Q can help if you
need to place two channels very close together without having them over-
lap (such as might be necessary to apply two dierent level settings over a
small range of the curve) or if you want to apply a single level change over
a wide portion of the curve. The ability to narrow the range of inuence by
increasing a channel’s Q value will prove useful when we discuss some of
the hazards of equalization shortly.
The goal of applying equalization, as we’ve already said, is to get a
smooth frequency response. That means getting the frequency response
curve as at as possible. In doing this, it is possible to get a bit carried
away with the equalizer settings and create conditions that could place
dangerous demands on your equipment. The biggest danger to watch
out for is stacking equalizers. Stacking refers to setting two equalizers at
the same frequency or at very close frequencies and applying a signicant
boost to both equalizers. This can place very exaggerated demands on
the subwoofer and may lead to distortion or damage to your speaker. If
you need to place two equalizers close together and set the level to a
positive value, the equalizers’ Q values should be set as high as possible
to limit interaction between the two equalizers. (Stacking is a one-way
street, as two closely-spaced equalizers that both have their levels set to a
negative value will not place the subwoofer at risk.)
ROOM EQUALIZATION EXAMPLE
At this point, you should be ready to use the SMS-1’s system settings, test
tones, system response curve, and parametric equalizers to perform a
very eective room equalization in your space. We realize, however, that
this can be a daunting task, even for an outlaw such as yourself. With that
in mind, we wanted to take a few pages to show you a simple example of
room equalization.
The rst step in a manual equalization is to take a look at what you have to
work with. We will assume for a moment that you have spent some time
in the System Settings screen getting crossover, subsonic lter, phase,
and other settings adjusted to your liking and that you’ve adjusted all
the volume levels and crossover settings. With all that done, we start out
with the eight equalizers at their default frequencies and zeroed out. The
System Response curve may look something like the one to the left.
You will likely notice more than one peak or dip – an area where the
response shifts more than a couple dB away from the baseline level
established when you set your volumes. Those are going to be the points
that we will focus our attention on. In this case, you may notice a peak at
about 32Hz and a dip near 52Hz along with some other uctuations. No
two curves will be the same, so for this example we are going to look spe-
cically at those two points as a typical dip and a typical peak. Addressing
those two conditions will give you the foundation for handling whatever
your room throws at you.