Distortion adds harmonics to a bass signal, making it audible on small speakers that cannot reproduce low frequencies

Small speakers (earbuds, phone speakers, laptop speakers) cannot reproduce frequencies below ~150–200 Hz. A pure sine-wave bass fundamental at 80 Hz is inaudible on these systems. Distorting the bass creates harmonics at 160 Hz, 240 Hz, 320 Hz (and higher), which small speakers can reproduce. The listener’s auditory system reconstructs the missing fundamental from these harmonics (the ‘missing fundamental’ effect), so the bass appears to translate. This is why engineers intentionally add subtle distortion to kick drums and bass lines, especially in rap and urban styles: the mid-frequency harmonics carry the bass across all playback systems.

Examples

808 kick: pure sub at 60 Hz is inaudible on earbuds. Adding light saturation creates harmonics at 120 Hz and 180 Hz, which earbuds can reproduce, making the kick audible.

Assessment

Explain why adding subtle distortion to a sub-bass kick drum helps it translate to small speakers. What psychoacoustic phenomenon makes this effective?