Access virus indigo ii Manuale Utente
ACCESS VIRUS OS5
19
Filter Modulation
Now locate the FILT 1 MODE switch, which is
also located in the FILTERS section. It enables
you to select a filter operating mode from the
four available options:
also located in the FILTERS section. It enables
you to select a filter operating mode from the
four available options:
- LP
the low pass filter we have just discussed.
- HP
the high pass filter which works in the op-
posite manner of the low pass filter: It sup-
presses the lower frequencies in a signal and
lets the higher frequencies pass.
presses the lower frequencies in a signal and
lets the higher frequencies pass.
- BP
the band pass filter which suppresses
both ends of the tonal spectrum and allows
only a narrowly defined bandwidth of the
original sound to pass.
only a narrowly defined bandwidth of the
original sound to pass.
- BS
The band stop filter, band reject filter or
notch filter which works in the opposite man-
ner of the bandpass filter. 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.
ner of the bandpass filter. 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.
Now activate the different operating modes and
rotate the Cutoff pot to get a feel for the way
each filtering option works.
rotate the Cutoff pot to get a feel for the way
each filtering option works.
Along with the Cutoff pot, the RESONANCE pot
is the most important control feature of a filter.
The filter resonance increases the volume of the
frequencies located near the cutoff frequencies
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
is the most important control feature of a filter.
The filter resonance increases the volume of the
frequencies located near the cutoff frequencies
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 RES-
ONANCE setting in the different operating
modes in conjunction with different Cutoff set-
tings. You will find the effect that the RESO-
NANCE pot 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 of the notch decreas-
es; in other words more frequencies on both
sides of the filter frequency are allowed to pass.
ONANCE setting in the different operating
modes in conjunction with different Cutoff set-
tings. You will find the effect that the RESO-
NANCE pot 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 of the notch decreas-
es; in other words more frequencies on both
sides of the filter frequency are allowed to pass.
FILTER MODULATION
Of course we don’t want to require you to exe-
cute every sound modification manually by
twiddling pots. All kinds of sound modifications
in the VIRUS can be executed automatically
much in the way of your previous experiments
with the volume controls: The amplifier enve-
lope can be described as a variable curve
which, depending on the type and duration of
attack, hold and release data, automatically in-
fluences (turns it up or down) an imaginary vol-
ume pot.
cute every sound modification manually by
twiddling pots. All kinds of sound modifications
in the VIRUS can be executed automatically
much in the way of your previous experiments
with the volume controls: The amplifier enve-
lope can be described as a variable curve
which, depending on the type and duration of
attack, hold and release data, automatically in-
fluences (turns it up or down) an imaginary vol-
ume pot.
Similar procedures are applicable to the filter
frequencies. The FILTERS section features its
own envelope, the structure of which is identi-
cal to the amplifier envelope, located directly
above the amplifier envelope on the control fea-
ture panel. Much like the amplifier envelope, the
filter envelope automatically “rotates” the Cutoff
pot.
frequencies. The FILTERS section features its
own envelope, the structure of which is identi-
cal to the amplifier envelope, located directly
above the amplifier envelope on the control fea-
ture panel. Much like the amplifier envelope, the
filter envelope automatically “rotates” the Cutoff
pot.
However there is one significant difference be-
tween the two envelopes. With the amplifier en-
velope, you are always dealing with an initial
volume level of 0 because of course you want
absolute silence prior to the beginning of a
note. After the RELEASE phase, it is again
tween the two envelopes. With the amplifier en-
velope, you are always dealing with an initial
volume level of 0 because of course you want
absolute silence prior to the beginning of a
note. After the RELEASE phase, it is again
SELECT
SELECT
MODE
MODE
FILT 1
FILT 1
FILT 2
FILT 2
EDIT
EDIT
BP
BP
BS
BS
HP
HP
LP
LP
FILT 2
FILT 2
FILT 1
FILT 1