We normally talk about harmonics being frequency components that exist at integer multiples of the fundamental note’s frequency, and therefore are higher in pitch. Subharmonics are lower in pitch than the fundamental, and typical reside at integer divisions of fundamental’s pitch.
For example: “concert A” is often defined as having a pitch of 440 Hz (cycles per second). That would be the pitch of its fundamental, which is also its first harmonic. The second harmonic is at 440 x 2 = was 880 Hz, the third at 440 x 3 = 1320 Hz, the fourth at 440 x = 1760 Hz, etc. The second subharmonic, by contrast, would be at 440 ÷ 2 = 220 Hz, the third subharmonics at 440 ÷ 3 = 146.67 Hz, the fourth at 440 ÷ 4 = 110 Hz, etc.
There are a few instruments based on subharmonic synthesis, including Oskar Sala’s Mixtur Trautonium. Doepfer’s A-113 Subharmonic Generator module recreates the subharmonic divider portion of it. This movie demonstrates dividing the fundamental’s frequency, and this movie demonstrates mixing those subharmonics.« Back to Glossary Index