Tutorials and Topics - Peabody Computer Music

Tutorial 7Synthesis:Additive synthesisSummaryAdditive synthesis is the process of synthesizing new complex tones by adding tonestogether. Since pure sine tones have energy at only one frequency, they are thefundamental building blocks of additive synthesis, but of course any signals can be addedtogether. The sum signal may need to by scaled by some constant signal value less than 1in order to keep it from being clipped by the DAC.In order for the timbre of a complex tone to remain the same when its pitch changes, eachpartial must maintain its relationship to the fundamental frequency. Stating the frequencyof each partial in terms of a ratio to (i.e., a multiplier of) the fundamental frequencymaintains the tone’s spectrum even when the fundamental frequency changes.In order for a complex tone to have an interesting timbre, the amplitude of the partialsmust change with a certain degree of independence. The function object allows you todraw control shapes such as amplitude envelopes, and when function receives a bang itdescribes that shape to a line~ object to generate a corresponding control signal.See AlsofunctionGraphical function breakpoint editor103