Bitcrusher

A Bitcrusher is a digital audio effect, which produces a distortion by the reduction of the resolution or bandwidth of digital audio data.

A number stored digitally has a resolution given as n bits, where there are $2^n$ possible values of the number. If one reduces the number of bits used to store the number, the number of possible values of the number is decreased, and thus the resolution decreases, leading to distortion. For example, a standard CD has a resolution of 16 bits, thus there are $2^\; \{16\}$ possible values for any given part of the musical waveform. If this is reduced to approx. 8 bits, distortions can be noticed, reducing the quality. These distortions add to the original overtone in such a way that the wave shape becomes angular. This can produce a “warmer” sound impression than the original waveform, especially if the wave is rounded off in certain ways. Often this is used with techno or electronic music consciously, without regard to sound quality.

An example of a sound distorted by a bitcrusher is in the introduction to the song “Chemicals” from the album “The Notwist”. The samples used in the Roland TR-909 drum machine, for example, has a resolution of 6 bits, leading to a similar sound.