Long description

This figure consists of two 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 seems to follow the ideal response exactly in the passband and stop band – that is, it does not oscillate but remains horizontal. However, it does not drop vertically between one and the other at the cut-off frequency of 5000, but descends diagonally between frequencies of approximately 4200 and 5800.

In screenshot (b), the actual response is very similar to that in screenshot (a). However, it appears to have a slight ripple in the passband, and to descend slightly more rapidly around the cut-off frequency.