R.A.B.O.S. Online
Now that you have obtained the data necessary to make final
adjustments, a few more calculations are required to determine
the ideal position of the three bass optimization controls.
These calculations are covered in detail, and are available
for your reference in the remaining pages of this owner’s
guide. It is recommended that you read through to get a better
understanding of the functions and benefits of R.A.B.O.S.
However, if you have access to the Internet, you may choose
to skip to “Adjusting the R.A.B.O.S. Equalizer” on page 19, and
have your settings calculated by Infinity's online R.A.B.O.S.
calculator. You can find this in the “Owner Info” section of our
Web site at www.infinitysystems.com.
What Does a Parametric Equalizer Do?
The R.A.B.O.S. system uses one band of parametric equalization
for response correction. Parametric equalizers are the most
versatile class of filters. The effect an equalizer will have on the
signal is dependent on three parameters.
Frequency:
The equalizer will have maximum effect at one
frequency, usually described as the center frequency.
Level:
This refers to the amount of cut (in dBs) the equalizer
is set for.
Bandwidth:
Defines the range of frequencies over which the
equalizer will have an effect. On the Modulus subwoofer, this
adjustment is abbreviated as “Width.”
Only parametric equalizers allow independent adjustment of all
three parameters.
These will be explained more fully in the sections that follow.
Completing the Measurement Template
Along the bottom of the Measurement Template are three fields
where you will enter the equalizer settings needed to complete
system optimization.
These instructions are based on the example in Figure 19.
Use this tutorial to become familiar with the process. Strategies
for several other test results will be presented later. After you
have completed these three entry fields, you will be ready to
perform the adjustments, completing R.A.B.O.S. optimization.
Frequency
The frequency of the R.A.B.O.S. equalizer may be adjusted to
any one of nineteen frequencies from 20Hz to 80Hz. This defines
where you are going to apply equalization.
Width
The frequency range of the R.A.B.O.S. equalizer may be set from
5% to 50% of an octave in 21 steps.This setting defines
how much of the subwoofer’s output will be equalized.
Width is expressed as a percentage of an octave. For example, a
width setting of 25% means the equalizer will affect a frequency
band of 1/4 of an octave; 1/8 of an octave above and 1/8 of an
octave below the center frequency.
The octave is a logarithmic expression. From any point
in the spectrum, one octave above or below that point is always
double or half the frequency.Therefore, one octave above 100Hz
would be 200Hz. One octave below 100Hz is 50Hz.
In the section that follows, we will discuss the use of the
Width Selector.
Effect of adjustable width
MODULUS
14
F
IGURE
20
