Specifications

SUBTRACTOR SYNTHESIZER
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Filter 2
A very useful and unusual feature of the Subtractor Synthesizer is the presence
of an additional 12dB/Oct lowpass filter. Using two filters together can produce
many interesting filter characteristics, that would be impossible to create using a
single filter, for example formant effects.
The parameters are identical to Filter 1, except in that the filter type is fixed, and
it does not have filter keyboard tracking.
D To activate Filter 2, click the button at the top of the Filter 2 section.
Filter 1 and Filter 2 are connected in series. This means that the output of Fil-
ter 1 is routed to Filter 2, but both filters function independently. For exam-
ple, if Filter 1 was filtering out most of the frequencies, this would leave Filter
2 very little to “work with”. Similarly, if Filter 2 had a filter frequency setting of
“0”, all frequencies would be filtered out regardless of the settings of Filter 1.
✪ Try the “Singing Synth” patch (in the Monosynth category of the
Factory Sound Bank) for an example of how dual filters can be
used.
Filter Link
When Link (and Filter 2) is activated, the Filter 1 frequency controls the fre-
quency offset of Filter 2. That is, if you have set different filter frequency values
for Filter 1 and 2, changing the Filter 1 frequency will also change the frequency
for Filter 2, but keeping the relative offset.
✪ Try the “Fozzy Fonk” patch (in the Polysynth category of the Fac-
tory Sound Bank) for an example how linked filters can be used.
! Caution! If no filter modulation is used, and the filters are linked,
pulling down the frequency of Filter 2 to zero will cause both filters
to be set to the same frequency. If combined with high Res settings,
this can produce very loud volume levels that cause distortion!
Envelopes - General
Envelope generators are used to control several important sound parameters in
analog synthesizers, such as pitch, volume, filter frequency etc. Envelopes gov-
ern how these parameters should respond over time - from the moment a note is
struck to the moment it is released.
Standard synthesizer envelope generators have four parameters; Attack, Decay,
Sustain and Release (ADSR).
There are three envelope generators in the Subtractor, one for volume, one for
the Filter 1 frequency, and one modulation envelope which has selectable mod-
ulation destinations.
The ADSR envelope parameters.
Attack
When you play a note on your keyboard, the envelope is triggered. This means it
starts rising from zero to the maximum value. How long this should take, de-
pends on the Attack setting. If the Attack is set to “0”, the maximum value is
reached instantly. If this value is raised, it will take time before the maximum
value is reached.
For example, if the Attack value is raised and the envelope is controlling the filter
frequency, the filter frequency will gradually rise up to a point each time a key is
pressed, like an “auto-wha” effect.
Attack
(time)
Decay
(time)
Sustain
(level)
Release
(time)
Key Down
Key Up
Level
Time