It has been suggested that this article or section be merged with DC coefficient. (Discuss)

DC offset is an offsetting of a signal from zero. The term originated in electronics, where it refers to a direct current voltage, but the concept has been extended to any representation of a waveform. DC offset is the mean amplitude of the waveform; if the mean amplitude is zero, there is no DC offset. Wikipedia does not have an article with this exact name. ... It has been suggested that this article or section be merged with DC offset. ... Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ... Waveform quite literally means the shape and form of a signal, such as a wave moving across the surface of water, or the vibration of a plucked string. ...

DC offset is usually undesirable. For example, in audio processing, a sound that has DC offset will not be at its loudest possible volume when normalized (because the offset consumes headroom), and this problem can possibly extend to the mix as a whole, since a sound with DC offset and a sound without DC offset will have DC offset when mixed. It may also cause other artifacts depending on what is being done with the signal. Audio normalization is the process of increasing (or decreasing) the amplitude (volume) of a digital audio recording. ... Headroom (band) is the name of a band HeadRoom is the name of a headphone equipment company Headroom is a term used in signal processing (audio, data, etc) to refer to the maximum allowable signal level before compression or distortion. ...

DC offset can be reduced in real-time by a one-pole one-zero high-pass filter. When one already has the entire waveform, subtracting the mean amplitude from each sample will remove the offset if the offset is constant throughout the waveform. Otherwise, the high-pass filter should be used. A high-pass filter is a filter that passes high frequencies well, but attenuates (or reduces) frequencies lower than the cutoff frequency. ...

See also

• DC coefficient