|After clicking OK two times to close dialogs, please left-click on BIQUAD
to select it and right click to choose "Open a Monitor".
Then its frequency response appears. The following figure is after adjusting the scale, View -> Scale Change on the menu. It's a LPF which cutoff is 4000Hz.
Now, let's see BIQUAD Parameters dialog again. The feedback side, "b1" and "b2" are not inverted in the transfer function but inverted in the block diagram.
Why are they inverted in the block diagram?? You may understand that after seeing this site (Wikipedia). The coefficients of feedback side are inverted in the differential equation, that has the same meaning as the block diagram.
However, please see this site (UCCS). The coefficients of feedback side are not inverted in the block diagram but inverted in the transfer function. Which one is correct??