This selects the parts of the sound which will be
affected by the ﬁlter, as described below.
Low pass ﬁlter
This is the most common type of ﬁlter, which
passes the low frequency range and cuts the high
frequency range. When the overtones of the high
range are cut, a bright sound will become darker
24 dB/oct and 12 dB/oct see the steepness of the
cut. 24 dB/oct means that the gain will decrease 24
dB in one octave (i.e., as the frequency doubles). A
12 dB/oct ﬁlter would decrease the gain 12 dB in
one octave. The 24 dB/oct ﬁlter produces a steeper
High pass ﬁlter
This type of ﬁlter passes the high frequency range
and cuts the low frequency range. Use this when
you wish to make the sound thinner. However if
the cutoff frequency (Frequency) is raised exces-
sively high, the volume will become very low.
When "Resonance" is set to a higher value, the
overtones in the region of the cutoff frequency will
be boosted as shown in the diagram below, giving
a distinctive character to the sound.
When resonance is applied
When this is set to 0, there is no emphasis, and fre-
quencies beyond the cutoff will simply diminish
At medium settings, the resonance will alter the
timbre of the ﬁlter, making it sound more nasal, or
more extreme. At very high settings, the resonance
can be heard as a separate, whistling pitch.
To make the resonance track the keyboard pitch,
see "4–2a: Keyboard Track" (☞PG p.17).
Selecting a ﬁlter to modify the tone
Here's how to select a ﬁlter type and adjust the
"Frequency" (cutoff frequency) and "Resonance"
1. Use "Type" to select a ﬁlter type.
2. If you've selected Low Pass Resonance as the
Low Pass Resonance: This is a 24 dB/octave
low pass ﬁlter with resonance.
Low Pass & High Pass: This is a 12 dB/octave
low pass ﬁlter and a 12 dB/octave high pass
ﬁlter connected in series.
ﬁlter type, you can set the parameters for Filter
"Frequency" speciﬁes the cutoff frequency.
Overtones above the speciﬁed cutoff frequency
will be diminished, making the tone more
"Resonance" speciﬁes the resonance level. This
boosts the overtones in the region of the
speciﬁed "Frequency," giving the sound a
If you've selected Low Pass & High Pass as the
ﬁlter type, you can use the Filter A parameters
to adjust the low pass ﬁlter and the Filter B
parameters to adjust the high pass ﬁlter.
Overtones above the Filter A "Frequency" will
be diminished, making the sound more mellow
Overtones below the Filter B "Frequency" will
be diminished, decreasing the low-range and
making the sound thinner.