A method selects a period of delay in an FIR filter having (i) a plurality of delay elements and (ii) a plurality of coefficient taps each associated with a portion of an input signal in corresponding stages of delay from a corresponding delay element, in which at least one delay element has a period of delay that is selectable. The method includes measuring components of an input signal so as to identify a sequence of components that are smaller than another sequence of larger components. The method includes setting the selectable period of delay to prevent application of the identified sequence of smaller components of the input signal to the coefficient taps.