Korg Synthesizer/Vocoder microKORG Owner's Manual page 31

6. FILTER
TYPE
-12dB BPF ( ):
-12dB/oct BPF (Band Pass Filter)
allows a frequency band in the re-
gion of the cutoff frequency to pass,
and cuts the remaining frequencies.
Figure 6-2
It is used when you wish to empha-
BPF (Band Pass Filter)
size only a specific portion of the
frequency range.( Figure 6-2)
Use this when you want to empha-
size just a specific region of the
sound. For example, you can use
this to create a bandwidth-limited
sound similar to sound heard from
a small radio or a telephone.
-12dB HPF ( ):
-12dB/oct HPF (High Pass Filter)
allows frequencies above the cutoff
frequency to pass, and cuts the
lower frequencies. Use this when
Figure 6-3
you wish to make the sound thin-
HPF (High Pass Filter)
ner. However if the cutoff frequency
is raised excessively, the volume
will decrease significantly. ( Fig-
ure 6-3)
For example you can use the HPF
to purposely attenuate the low-fre-
quency region of a sound that will
be played together with other low-
frequency instruments, in order to
differentiate that sound from the
other instruments.
— SYNTH
Frequency
Cutoff
Frequency
Cutoff
Filter oscillation
If you raise the resonance to a high value, it will oscillate (produce a
sound) at the frequency specified by the cutoff frequency. You can use
filter oscillation ("self-oscillation") as a sound source. If the filter is
oscillating, the "CUTOFF" parameter that normally adjusts the tone will
instead control the pitch of the oscillation. This can be used in a variety of
ways. Whistling is a typical example, and can be produced by adjusting
the ADSR parameters of the filter EG. You can also try setting "FILTER EG
INT" to a negative value. Another possibility is to select the MOD wheel
or LFO 1/2 as a source in Virtual Patch, and use it to control "CUTOFF" as
a destination.
FILTER KEY TRACK
Keyboard Track operates ac-
cording to the pitch that is con-
trolled by pitch bend, and trans-
pose. It is not affected by pitch
changes produced by vibrato or
Virtual Patch.
Figure 6-5
Note off
Note on
Sustain Level
Attack Decay Release Time
Time
Time
Figure 6-6
Cutoff
Int=+32 Int=+63
Note on Note on
Note off
Cutoff frequency
specified by
"Cutoff"
Figure 6-7
Cutoff
Int=–32 Int=–63
Cutoff frequency
specified by
"Cutoff"
Note off
Note on Note on
Time
Note off
Int=0
Time
Int=0
Note off
Time
25