Graphic equalizers are a great tool for live and studio application, but are somewhat limited as far as being precise with the frequencies they manipulate. For example, the screen shot below show the Acoustica equalizer that ships with Beatcraft and Mixcraft.
This is a 10 band eq, notice I have pulled out 125Hz completely. Since this is a 10 band, this action has also affected 64 through 249Hz. Not very precise is it? Even so, this is how graphic equalizers are supposed to behave. Graphic equalizers such as the one shown above are meant for use as more of an expanded "low-mid-high" type of control.
A parametric equalizer is a different tool altogether. You need to use one AFTER you have tweaked your sound with the graphic eq. Here's the scenario, say you have worked on your kick drum sound and got it pretty close to what you want, but when the drummer (or Beatcraft) goes into a double bass pattern, the kick drowns everything else out and sounds like it got louder and is about to blow your speakers. Open up a can of parametric on it's ass :-)
I have decided that around 125Hz is what is causing the above mentioned response from my kick sound. So I take NyquistEQ and pull down 125Hz ONLY, this does not affect a load of other surrounding frequencies like the graphic does. I have the "spread" only slightly pulled apart, so it will more likely affect 122 to 128Hz, but if I put the dots right on top of each other, it would then only affect the frequency I tell it to. See the screen shot below.
NyquistEQ does not have any frequency markers, which I find strange. But it really does not matter, because you will be using it "by ear" anyway. After getting the sound you want, SAVE THE PRESET!
Happy parametric-ing!