Harmonic Bars

The harmonic bars are the basic fingerprint of a sound in Sine Machine.

Each bar represents a harmonic. The height is the volume of the harmonic.

To specify the volume of the fundamental frequency, change the blue bar on the far left.

You can change any harmonic in the harmonic series up to the 32nd harmonic. This “basic shape” gets applied to every note you play.

Note: The max volume of any given harmonic is 1/f, where f is the harmonic number.

Harmonics above the 32nd

You sometimes see additive synths that give you amplitude control over the 64th or 128th or even 256th partials. Wow! So much power!

This sounds cool on paper, but is misleading can even be unhelpful musically.

Psychoacoustic research consistently demonstrates that the lower the harmonic, the more it “matters” to the DNA of a sound. In most cases, editing the 63rd partial is probably going to be a waste of your time.

In fact, we can’t even individually hear harmonics after the 5-10th (depending on training). Andrew Oxenham says it best:

The higher-numbered harmonics, which do not produce individual peaks of excitation and cannot typically be heard out, are often referred to as being “unresolved.” The transition between resolved and unresolved harmonics is thought to lie somewhere between the 5th and 10th harmonic…

If we let you edit up to 256 partials, then we’d be presenting you with individual control for 246 partials that people can’t even individually distinguish. Worse, it would make it hard to to edit those first 5 or 10 very important partials.

However, we do want our sounds to go up to nyquist, so Sine Machine extrapolates all odd harmonics from the 31st partial and even harmonics from the 32nd partial.

Harmonic Amplitude Scaling

Humans enjoy tonal sounds that have most energy at lower harmonics.

This is in part because our hearing is optimized for the human speaking voice range of 1-5khz. This means that lower frequencies have to be much louder to be perceived as “the same volume”.

Equal loudness care of Wikipedia

Again lot of additive synths make the mistake of giving you the same volume scaling for each harmonic. This means, most of the time, higher harmonics will end up much louder than we’re used to hearing them in music and nature, resulting in very harsh screechy sounds.

To mitigate this, Sine Machine scales the maximum amplitude for any given harmonic to 1/f where f is the number of the harmonic.

This means the 2nd harmonic’s volume is scaled down by 1/2, the third harmonic by 1/3 etc.

What does this mean, exactly? It means with all bars at their maximum value, you will get a sawtooth wave.

If you do want to create harsher sounds with higher harmonics, you can turn down the lower harmonics.