➕Additive Synthesis

Harmonics

Under 'Instrument type', pick 'Harmonics'

Here are the harmonics controls. These change the amount of high frequencies and low frequencies present in the signal.

Click on the lowest vertical line, drag down and drag right to 'delete' all of the blue lines:

The orange lines show the octaves. The first orange line is the fundamental (lowest) note. The second orange line is one octave higher, the third line an octave above that, etc.

Click and drag up to activate frequencies. Activating more of the orange lines makes a purer signal:

Adding more of the non-orange frequencies creates a harsh-sounding signal:

Spectrum

Instead of 'Harmonics', you can pick the 'Spectrum' instrument type.

Here you can design more experimental sounds.

In fact, the standard drumset is just a series of spectrums: