User Manual

43
SPECTRALIS 2
The analog filter section
to access the parameter pages, which allow you to change the filter frequencies.
You should see the following menu in your display:
1/9:24dB Lowpass: Cutoff Modulation LFO
FMWve:0 FMRte:0 DmDpt:0
It is plain to see, that this menu does not deal with envelope-amount EG-depth.
So push the [Page-Up]-Button two times to access the following page:
3/9:24dB Lowpass: Filter Control
Exp:37 Reso:238 EgAm:63 Kscl:4
“EgAm” (envelope generator amount) confirms that you have reached your target.
Play a note on your keyboard, hold the key down and first turn the (CutOff-LP)-
encoder to the left until you hear no more change to the filter-frequency - in other
words until the sound does not get any duller. Now, when you are also turning down
the (EgAM)-encoder the filter is being closed further and the bass-sound begins to
pump. If you want to hear the full ”Oomph” of the filter, all you have to do is to
additionally reduce the resonance of the filter.
To do so, use the (Reso LP)-encoder and turn it to the left. Depending which key
on your keyboard you are playing you can now subject your monitors to a real test
;-)! Because of the reduction of the filter-feedback (resonance) it is not the overtone
structure around the cutoff-frequency that is being emphasized now, but the funda-
mental is getting louder.
If you increase the resonance further, the lowpass filter almost takes on the character
of a bandpass filter, emphasizing the range of the overtones around the cutoff
frequency, creating the perception of a more synthetic sound.
If you are increasing resonance to maximum level, the feedback will be so strong,
that the filter will start oscillating at the adjusted cutoff frequency. The term envelope
of course has already been explained in the DSP-synthesizer chapter earlier. To
complete the basic overview here is one more tip how you can access the envelope
of the lowpass filter. Before openening the envelope menu, you should increase the
”EgAM”-Parameter at the third lowpass-filter edit page (by pushing (CutOff LP)-
encoderswitch, selecting the third page with [Page-Up] and increasing the "EgAm"-
parameter) and reduce the filter-frequency (CutOff LP) as described before. Now
you can push the (EG-Depth)-button. You will now see the first page of the envelope
menus for the two analog filters:
1/4:Multimode: Volume Envelope Page1
Att:0 ^Dcy:0 Stn:255 Rls:10
This menu-page is not the one showing the envelope of the lowpass yet, but rather
the volume-envelope of the multimode filter. Remember? Each filter has two envelopes
– one to control level and one for the cutoff-frequency. By pushing the [Page-Up]-
button three times, you will arrive at your destination – the cutoff-frequency envelope
of the 24dB lowpass filter: