Clipping is distortion that occurs when an audio signal level (or "volume") exceeds the range of the chosen representation. In most cases, clipping is undesirable and so should be corrected by adjusting the level prior to the point (in the processing chain) at which it occurs.
In a sound processor, clipping could occur, as you might expect, when using the vol or gain effects to increase the audio volume. Clipping could also occur with many other effects.
For these reasons, it is usual to make sure that a sample's signal level has some "headroom", i.e. it does not exceed a particular level below the maximum possible level for the given representation. Some standards bodies recommend as much as 9dB headroom, but in most cases, 3dB (around 70% linear) is enough. Note that this wisdom seems to have been lost in modern music production; in fact, many CDs, MP3s, etc. are now mastered at levels above 0dBFS i.e. the audio is clipped as delivered.
The stat and stats effects can assist in determining the signal level in a Hollywood sample. The gain or vol effect can be used to prevent clipping, e.g.
gain -6 treble +6 |
guarantees that the treble boost will not clip.
If clipping occurs at any point during processing, the plugin will display a warning message to that effect.