Tip for cheap and easy filter plots:
Since I wasn't able to find a software sweep generator and plotter that worked
correctly, anytime I needed to look at the freq response of a phaser, filter or
other device, I had to run white noise through it and then look at an fft
analysis of it. However, that produces an ugly and crude plot. So I turned a
synth into a sinewave sweep generator, run that through the device in question,
and record into a wave editor application. The way it squashes down a wave to
fit on the screen ends up producing just the plots I wanted. In something like
CoolEdit, one can open up the fft analysis and move the line cursor over the
plot in the background and it will tell you the freq at that point, so you can
tell what frequencies the peaks and notches are at. Here's a plot of the Nord
phaseshifter:
http://home.att.net/~elhardt/Nord_Phaser_Plot.jpgGood enough for publishing. If you don't want a bipolor plot, just chop it off
across the center. Only drawback is you don't have the log graph overlaid
ontop. That could be applied in photoshop (or equivilant) though.
-Elhardt