Access Virus Rack User Manual page 25

Now we'll look at a parameter that is not
assigned a dedicated knob of its own,
but can be dialed up in the display. This
type of parameter may be selected via
the PARAMETER buttons and then
adjusted with the VALUE knob or the
VALUE buttons.
Select the FILTER 1 Mode parameter via
the PARAMETER buttons. To do this,
make sure that the display is still in the
filter section FILT. This parameter enables
you to select a filter operating mode
from the four available options:
the low pass filter we have just
LP
discussed.
the high pass filter which works in
HP
the opposite manner of the low pass
filter: It suppresses the lower frequen-
cies in a signal and lets the higher fre-
quencies pass.
the band pass filter which sup-
BP
presses both ends of the tonal spec-
trum and allows only a narrowly
defined bandwidth of the original
sound to pass.
The band stop filter, band reject
BS
filter or notch filter which works in the
opposite manner of the bandpass fil-
ter. It allows all of the frequencies of a
signal except for a narrow frequency
band around the cutoff to pass. The
term "notch" is fairly descriptive; you
might say this filter chops a notch out
of the sound spectrum.
01111111111111111112
1 FILTER1
Mode Lowpass≤
61111111111111111154
Now activate the different operating
modes and rotate the CUTOFF encoder
to get a feel for the way each filtering
option works.
Along with the CUTOFF encoder, the
RESONANCE encoder is the most impor-
tant control feature of a filter. The filter
resonance increases the volume of the
frequencies located near the cutoff fre-
quencies and suppresses the more
remote frequencies. This sound shaping
feature has a striking effect - especially
when used in conjunction with the low
pass filter: it produces a nasal or honking
type of tone which increases as you turn
the resonance up. Experiment by varying
the RESONANCE setting in the different
operating modes in conjunction with dif-
ferent CUTOFF settings. You will find the
effect that the RESONANCE encoder
achieves is markedly different for the
band stop filter in comparison to the
effect it has on the other filter types: as
the resonance increases, the bandwidth
ACCESS VIRUS RACK 23
The First Filter