Novation KS4 User Manual

Contents

ADVANCED FEATURESThe Oscillator Menu• 35 •It can be seen that the resulting synced waveform has subsequentlybeen modified into a different shape. Altering a waveform’s shape in thisway introduces new harmonics into the sound which gives the resultingwaveform its distinctive synced sound qualities.It should be realised that the greater the difference in tuning between theOscillator waveforms, the more pronounced the sync effect will become,since more drastic changes will be made to the final synced waveform.Changing the pitch of one of the Oscillators during the duration of a note(for example, modulated by an LFO) will add a dynamic quality to thesynced sound.FM SynthesisThe next two menu options allow sounds based on FM (FrequencyModulation) synthesis to be created. Before looking at the operations ofthese controls, a little explanation of FM synthesis follows.Earlier in this manual, the basics of subtractive synthesis were intro-duced. Terms such as harmonics, timbre, waveforms and oscillatorsbecame familiar.FM Synthesis is the technique of using one waveform to FrequencyModulate - FM- another to produce a resultant more harmonically com-plex waveform.The following diagram illustrates that the higher the modulation betweenthe Modulating wave and the Carrier wave, the more the waveformchanges.In the illustration, the Oscillators are producing Sine waves. It is thechange in harmonics over time that makes a sound interesting to ourears.In FM synthesis, an envelope generator is inserted between the modula-tor and carrier waveforms so that there is control over of how much of thefrequency modulation is taking place with respect to time. Adding thisenvelope constructs the basic FM building block as shown in the nexillustration.It can be seen that the output waveform begins, being identical to thecarrier, but becomes more complex (harmonics are added) as the amountof FM modulation increases via the envelope. It then returns to a simplewave again as the envelope decays.The timbre of the Waveform is changing with time. This is the opposite ofsubtractive synthesis where a low pass Filter is used to remove harmon-ics.To complete a simple synthesizer, a further envelope is added to controlthe output volume.The complete FM building block is illustrated below.OSC 2 is able to FM OSC 3 via a dedicated FM envelope. It is importantthat it is realized that this Envelope is used only for FM purposes and isnot one of the Envelopes available on the front panel.The diagram below shows in block diagram format how the KS 4 / KS 5can produce FM sounds.The easiest way to be totally familiar with FM is to take one of the factorypreset FM sounds, for example Bank 2 - 09 (Sound 209), a bell soundand to experiment by modifying the various FM settings.osc 1- modulatorosc 3- carrieroutput waveformmodulation level = 0 = 30 = 90Modulator OscillatorModulation Level = 0Carrier OscillatorOutput Waveform= 30 = 90osc 1- modulatorosc 3- carrieroutput waveformenvelopemodulationlevel = 20ModulatorEnvelope Modulation = 20CarrierOutput Waveformmodulatorenv - used tocontrol FMmodulationamountenv - used tocontrol amplitudeof sound overtimecarrierModulatorCarrierEnvelope usedto control FMModulationamountEnvelope usedto controlAmplitudeOsc 3Operator 1Operator 2Osc 2FM EnvAmp EnvOSC 2OSC 3FM EnvelopeAMP EnvelopeOscillator 1Oscillator 2Synced waveform