Clipping (signal Processing) - Audio

Audio

In the audio domain, clipping may be heard as general distortion or as pops.

Because the clipped waveform has more area underneath it than the smaller unclipped waveform, the amplifier produces more power than its rated (sine wave) output when it is clipping. This extra power can damage any part of the loudspeaker, including the woofer, or the tweeter, by causing over-excursion, or by overheating the voice coil. It may cause damage to the amplifier's power supply or simply blow a fuse.

In the frequency domain, clipping produces strong harmonics in the high frequency range (as the clipped waveform comes closer to a squarewave). The extra high frequency weighting of the signal could make tweeter damage more likely than if the signal was not clipped. However most loudspeakers are designed to handle signals like cymbal crashes that have even more high frequency weighting than amplifier clipping produces, so damage attributable to this characteristic is rare.

Many electric guitar players intentionally overdrive their amplifiers (or insert a "fuzz box") to cause clipping in order to get a desired sound (see guitar distortion).

Some audiophiles believe that the clipping behavior of vacuum tubes with little or no negative feedback is superior to that of transistors, in that vacuum tubes clip more gradually than transistors (i.e. soft clipping, and mostly even harmonics), resulting in harmonic distortion that is generally less objectionable. In general though, the distortion associated with clipping is unwanted, and is visible on an oscilloscope even if it is inaudible. Even in a transistorised amplifier with hard clipping, the gain of the transistor will be reducing (leading to nonlinear distortion) as the output current increases and the voltage across the transistor reduces close to the saturation voltage (for bipolar transistors), and so "full power" for the purposes of measuring distortion in amplifiers is usually taken as a few percent below clipping.