Long description

This figure consists of three parts, each showing a screenshot from Signal Wizard. In each case, the ideal filter response is shown as a horizontal line at 1 below the cut-off frequency and a horizontal line at 0 above the cut-off frequency, with the cut-off frequency represented as a vertical line at 5000. The actual response is shown as a second line.

In screenshot (a), the actual response oscillates slowly around 1, then descends diagonally between frequencies of approximately 3700 and 6300, then oscillates slowly around 0.

In screenshot (b), the actual response oscillates more rapidly around 1, then descends diagonally between frequencies of approximately 4700 and 5300, then oscillates more rapidly around 0. The oscillations die away more quickly than in screenshot (a).

In screenshot (c), the actual response oscillates very rapidly around 1, then descends diagonally between frequencies of approximately 4900 and 5100, then oscillates very rapidly around 0. The oscillations die away more quickly than in screenshot (b).