Sound Generation
33
▶
Set Decay (Comb Filter) to [ 1000 ms ]
▶
Set Pitch (Comb Filter) to [ 0.00 st ] and slowly turn up the Encoder value
while playing some notes. Then dial in [ 60.00 st ].
ߊ At the lower end of the Pitch range, you will notice audible “reflections”
of the delay line. Their number depends on the Decay setting (resp. the
feedback level). At higher pitches, resp. shorter delay times, the reflec-
tions grow increasingly dense until they sound like a static tone that has
a dedicated pitch.
߃
Excursion – Some Nuts and Bolts of Physical Modelling
What you have just programmed into your C15 is a very simple example of a
sound-generation type usually referred to as “Physical Modelling”. It comprises a
dedicated signal source – the exciter – and a resonator, in our case the Comb Filter.
The exciter signal stimulates the resonator, generating a “ringing tone”. Matching
sympathetic frequencies of exciter and resonator are boosted, others attenuated.
Depending on the pitch of the exciter (Oscillator pitch) and the resonator (delay time
of the Comb Filter), these frequencies can vary a lot. The audible pitch is determined
by the resonator. This method is characteristic of many acoustic instruments, e.g. a
plucked string or a blown flute stimulating a resonating body of sorts.
More advanced Parameters / Refining the Sound
Key Tracking:
▶
Press Decay (Comb Filter) until Key Trk is highlighted in the display.
▶
Sweep the Encoder across the entire range and dial in approx. [ 50.0 % ].
ߊ Now, the Decay at higher note ranges is reduced, compared to lower
note ranges. This produces a more “natural feel”, useful for many sounds
which are to resemble specific acoustic qualities.
To Next Page
