Sub-bass

Sub-bass sounds are those approximately below 60 Hz and extending downward to include the lowest frequency humans can hear, typically 20 Hz. In this range, human hearing is not very sensitive, so sounds in this range tend to be felt more than heard. Sound systems often feature one or more subwoofer loudspeakers that are dedicated solely to amplifying sounds in the sub-bass range. Sounds below sub-bass are called infrasound.

Hearing and usage

20 Hz is considered the normal low frequency limit of human hearing. When pure sine waves are reproduced under ideal conditions and at very high decibels, a human listener will be able to identify tones as low as 12 Hz.

Audio tracks known as bass tests use sub-bass frequencies which are used to test or to demonstrate the capabilities of audio equipment. High-end subwoofers can accurately reproduce sound to about 18 Hz ±2 dB.

Sub-bass energy is popular in dance music, where the low frequencies involve energy from the kick drum, the bass guitar and electronic synthesizers. Particular genres such as drum and bass and dubstep often feature the whole bass-line produced in sub-bass frequencies. Much experimental music uses sub-bass, in particular drone music, where the majority of the sound can often be in the sub-bass range. Often, hip hop and rap songs feature prevalent sub-bass. The pedal range on pipe organs also often extends into the sub-bass range; the bottom note of a 16' stop is typically tuned to 32 Hz, a 32' stop at 16 Hz.