Most unit generators have an output range of -1.0 to 1.0, or 0dB in audio terms. It is often useful to scale and offset this output, as we have seen in the above examples. For this reason, the majority of unit generators have :mul and :add inputs. When left at their default values, processing is optimized out so they do not incur a performance penalty. When set to a scalar value or connected to a control-rate source, less processing power is consumed than when connected to a audio-rate source.