What is additive synthesizer?
In additive synthesis, you start out with nothing and build a sound by combining multiple sine waves of differing levels and frequencies. As more sine waves are combined, they begin to generate additional harmonics. In most additive synthesizers, each set of sine waves is viewed and used much like an oscillator.
Is serum an additive synth?
Additive synthesis
Serum's Wavetable Edit view allows you to transform any waveform into sinewaves using the “Wave to FFT” button on the left. This allows you to analyze any waveform that you import into Serum and see which sinewaves create its sound.