Three-Domain Connections

Each movie illustrates how the frequency response of an FIR filter depends on its zero locations. Also the dependence of the impulse response can be observed, but remember that the impulse response for an FIR filter is equal to the filter coefficients.

Movie	Description
	FIR filter with two zeros. Notice changes in the impulse response h[n] and the frequency response as the complex zero pair is moved around the unit circle (changing the angle of the zeros).
	FIR filter with three zeros; one is held fixed at z = -1. Notice changes in the impulse response h[n] and the frequency response as the complex zero pair is moved around the unit circle (changing angle).
	FIR filter with ten zeros equally spaced around the unit circle. Notice changes in the impulse response h[n]and the frequency response as the zero at z = 1, is moved radially.
	FIR filter with ten zeros equally spaced around the unit circle. Notice changes in the impulse response h[n] and the frequency response as the zero pair at 72 degrees is moved radially.

McClellan, Schafer, and Yoder, Signal Processing First, ISBN 0-13-065562-7.
Prentice Hall, Upper Saddle River, NJ 07458. © 2003 Pearson Education, Inc.