The POLYMORPH has two filters working independently from another, to influence the sound of
the oscillators. They can be arranged either in series or parallel. This way you can create band
passes and band stops.
HIGHPASS - HIGH-PASS FILTER
The first filter is a high-pass filter with a roll off curve of 12dB per octave below the cutoff
frequency. Only frequencies above the set Cutoff point can pass through this filter unaffected.
<HIGHPASS-CUTOFF> - HIGH-PASS CUTOFF FREQUENCY
This parameter varies the frequency below which the bass is filtered out.
<HIGHPASS-RESONANCE> - HIGH-PASS RESONANCE
With this parameter you control the characteristics of the filter at the cutoff frequency. High
resonance settings cause an increase of the level in the area of the cutoff frequency. As a result the
filter has a nasal sound characteristic. An extreme resonance setting causes the filter to go into
self-oscillation and creates a sine tone, at the cutoff frequency. This is the reason the pitch of this
sine tone can be adjusted with <HIGHPASS-CUTOFF>.
<HIGHPASS-ENV-MOD> - HIGH-PASS FILTER - ENVELOPE SENSITIVITY
This parameter varies the amount by which the envelope generator modifies the HPF cutoff
frequency. When the control is positioned in the middle it has no influence. With negative values,
the greater the deflection of the envelope the lower the cutoff frequency of the filter. (ie. during
the envelope's attack, the HPF opens up letting more bass through.) With the knob set at positive
values, the cutoff frequency is made higher in proportion to the envelope amplitude, so the HPF
effect becomes much more severe on the peaks.
LOWPASS - LOW PASS FILTER
The POLYMORPH's other filter is a low-pass filter, which has a switchable rolloff curve of either
12dB or 24dB per octave. The LPF filters out the treble above the set cutoff frequency and only lets
the bass through.
16
Basics
CUTOFF-FREQ.
dB
f
RESONANCE
Highpass-Filter
dB
f
RESONANCE
CUTOFF-FREQ.
Lowpass-Filter
