Bitcrusher is a type of audio effect that has a low-quality distortion and creates distortion by reducing the resolution or the bandwidth of digital audio data. The sound resulting from the bitcrusher mimics the sounds of metal and sand. It’s worth mentioning that the perceived sounds tend to change according to the use of the bitcrusher. The sounds can vary from subtle, to warm, to extremely harsh depending on the amount of reduction. 

Digital Audio and the Bitcrusher

Digital audio involves a quick series of numeric samples that encode the changing volume of an audio waveform. To describe this waveform accurately, digital audio requires a large number of samples at a high sample rate. The higher the rate, the more accurate the waveform is. Hence, higher sample rates allow the accurate recording of higher frequencies.

Early digital equipment used much lower sample rates to conserve memory for stored audio. Sample rate reduction, also known as downsampling, intentionally decreases the sample rate to degrade the quality of the audio. When you reduce the sample rate waveforms, the high frequencies tend to lose power. As mentioned before, at extreme reduction levels, the waveform sound becomes metallic and harsh.

Samples in digital audio are recorded as real numbers and later stored in computer memory. As a result, a series of on and off memory bits encode these them. The larger the number of bits, the more accurate a sample encodes the instantaneous volume level of a sampled audio waveform. 

Resolution reduction intentionally reduces the number of bits used for audio samples, but as the bit depth decreases, the waveforms become more stair-stepped. When this happens, you can loose subtle volume variations. Also, at the extreme bit reduction, waveforms transform into clicks, so the waveform jumps abruptly from low to high and vice versa. 

The Bitcrusher effect involves at least two controls: one reduces the sample rate, while the other reduces the resolution.