subtones

Subtone is a term used in music and acoustics to describe a tone or tonal component that lies below a reference pitch, typically the main fundamental or the designated bass range of a piece. Because it is not a single standardized concept, subtone can refer to several related ideas: low‑frequency energy accompanying a sound, the presence of subharmonics produced by nonlinearities in a source, or a dedicated low‑frequency element added in synthesis to reinforce bass without increasing high‑frequency content.

In acoustics and signal processing, subtones may arise when the source exhibits nonlinear behavior, generating energy at frequencies that are submultiples of the main pitch (subharmonics). In electronic music and sound design, producers often implement a subtone with a sub‑oscillator or similar processing to extend the bass range, commonly in the range roughly 20–100 Hz.

Subtones influence timbre and perceived weight; they can alter the apparent loudness balance and impact the sense of grounding in a mix. Because subtone is used loosely, the term can also describe very low partials in a harmonic spectrum that listeners might not hear clearly as separate pitches but that shape the overall sound.

Distinguishing subtone from subharmonic is common: subharmonics are defined mathematically as frequencies equal to the fundamental divided by an integer; subtone is a broader, sometimes informal label for low‑frequency pitch content or energy.

See also: Subharmonic, Sub-bass, Bass frequency, Harmonic series, Synthesis, Sub-oscillator.