The harmonic series, or the overtone series is pretty simple. You have a fundamental frequency. The harmonics go upward in whole number multiples of that frequency. All of the overtones fit neatly "inside" the fundamental.
If you think of it as a rhythm, the fundamental is a beat, and each overtone is 2 per beat, 3 per beat, 4 per beat going up and up. As you continue to add overtones eventually you end up with a sawtooth wave.
The subharmonic series, or the undertone series is way more problematic. You have a fundamental frequency. The subharmonics go down from there, first is 1/2 the fundamental, then 1/3, 1/4, 1/5 and so on.
If you think if this as a rhythm, the fundamental is a beat. Then you have 2 beats (1/2 rate) then 3 beats (1/3 rate) then 4 beats (1/4 rate), etc. As you continue to add undertones, you don't end up with a pure wave at all. You end up with a strong attack, where all the waves are initially aligned (starting together), but they they spread out and disperse, never looping, ever.
I built a 48 wave subharmonic tone, and did some experiments with it. At a high frequency, it sounds like an 808 cymbal.
I really love the sound of subharmonic tones. I was messing with Reaktor's Subharmonic. The dumb thing is that it only gives you 4 sines. Would love to see an additive synth with a subharmonic mode. I'll add it to the list.
May 20, 2020 |
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