Soft Clipping

A soft clipper is similar to a hard clipper, but with the corners smoothed. A common choice of soft-clipper is the cubic nonlinearity, e.g. [492],

$$f(x) = \left\{\begin{array}{ll} -\frac{2}{3}, & x\leq -1 \\ [5pt] x-\frac{x^3}{3}, & -1 \leq x \leq 1 \\ [5pt] \frac{2}{3}, & x\geq 1. \\ \end{array} \right. \protect$$ (10.5)

This particular soft-clipping characteristic is diagrammed in Fig.9.3. An analysis of its spectral characteristics, with some discussion of aliasing it may cause, was given in in §6.13. An input gain may be used to set the desired degree of distortion.

Figure 9.3: Soft-clipper defined by Eq.(9.5).