Sub-bass sounds are the deep, low-register pitches below approximately 70 Hz (C₂ in

scientific pitch notation Scientific pitch notation (SPN), also known as American standard pitch notation (ASPN) and international pitch notation (IPN), is a method of specifying musical pitch by combining a musical note name (with accidental if needed) and a number id ...

) and extending downward to include the lowest frequency humans can hear, approximately 20 Hz (E₀). In this range, human hearing is less sensitive, so these notes tend to be felt more than heard. The low E-string on a

bass guitar The bass guitar, electric bass or simply bass (), is the lowest-pitched member of the string family. It is a plucked string instrument similar in appearance and construction to an electric or an acoustic guitar, but with a longer neck and ...

is usually tuned to 41.2 Hz, while the lowest note on a standard

piano The piano is a stringed keyboard instrument in which the strings are struck by wooden hammers that are coated with a softer material (modern hammers are covered with dense wool felt; some early pianos used leather). It is played using a keyboa ...

is A at 27.5 Hz.

Sound reinforcement system A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sou ...

s and

PA system A public address system (or PA system) is an electronic system comprising microphones, amplifiers, loudspeakers, and related equipment. It increases the apparent volume (loudness) of a human voice, musical instrument, or other acoustic sound sou ...

s often use one or more

subwoofer A subwoofer (or sub) is a loudspeaker designed to reproduce low-pitched audio frequencies known as bass and sub-bass, lower in frequency than those which can be (optimally) generated by a woofer. The typical frequency range for a subwoofer i ...

loudspeakers to amplify sounds in the sub-bass range. Sounds below sub-bass are

infrasound Infrasound, sometimes referred to as low status sound, describes sound waves with a frequency below the lower limit of human audibility (generally 20 Hz). Hearing becomes gradually less sensitive as frequency decreases, so for humans to perce ...

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

decibel The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a ...

s, a human listener will be able to identify tones as low as 12 Hz (G_–1). 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 Dance music is music composed specifically to facilitate or accompany dancing. It can be either a whole musical piece or part of a larger musical arrangement. In terms of performance, the major categories are live dance music and recorded da ...

, where the low frequencies involve energy from the

kick drum The bass drum is a large drum that produces a note of low definite or indefinite pitch. The instrument is typically cylindrical, with the drum's diameter much greater than the drum's depth, with a struck head at both ends of the cylinder. Th ...

(bass drum), the

and electronic

synthesizer A synthesizer (also spelled synthesiser) is an electronic musical instrument that generates audio signals. Synthesizers typically create sounds by generating waveforms through methods including subtractive synthesis, additive synthesis a ...

s and drum machines. Particular genres such as

house music House is a music genre characterized by a repetitive Four on the floor (music), four-on-the-floor beat and a typical tempo of 120 beats per minute. It was created by Disc jockey, DJs and music producers from Chicago metropolitan area, Chicago' ...

drum and bass Drum and bass (also written as drum & bass or drum'n'bass and commonly abbreviated as D&B, DnB, or D'n'B) is a genre of electronic dance music characterized by fast breakbeats (typically 165–185 beats per minute) with heavy bass and sub- ...

and

dubstep Dubstep is a genre of electronic dance music that originated in South London in the early 2000s. The style emerged as a UK garage offshoot that blended 2-step rhythms and sparse dub production, as well as incorporating elements of broken be ...

often feature a

bassline Bassline (also known as a bass line or bass part) is the term used in many styles of music, such as blues, jazz, funk, Dub music, dub and electronic music, electronic, traditional music, traditional, or classical music for the low-pitched Part ( ...

that consists mainly of sub-bass frequencies. Much

experimental music Experimental music is a general label for any music or music genre that pushes existing boundaries and genre definitions. Experimental compositional practice is defined broadly by exploratory sensibilities radically opposed to, and questioning of, ...

uses sub-bass, in particular

drone music Drone music, drone-based music, or simply drone, is a minimalist genre that emphasizes the use of sustained sounds, notes, or tone clusters – called drones. It is typically characterized by lengthy audio programs with relatively slight harm ...

, 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 keyboard A pedalboard (also called a pedal keyboard, pedal clavier, or, with electronic instruments, a bass pedalboard) is a keyboard played with the feet that is usually used to produce the low-pitched bass line of a piece of music. A pedalboard has lo ...

range on

pipe organ The pipe organ is a musical instrument that produces sound by driving pressurized air (called ''wind'') through the organ pipes selected from a keyboard. Because each pipe produces a single pitch, the pipes are provided in sets called ''ranks' ...

s also often extends into the sub-bass range; the bottom note of a 16′ stop is typically tuned to 32 Hz (C₁), a 32′ stop at 16 Hz (C₀).

References

Bass (sound) Pitch (music) {{music-stub