>> ...and what *is* the most advanced graphing tool known?
> 
> Gotta love POV-Ray for visualizing a surface.

Yeah, you do...

> I'm guessing then what the 
> Q parameter (to the resonant filter) then was adjust the elipticalness 
> of the surface, then ...

Precisely.

I've you look at the code I posted, I've got

#declare R1 = 0.5*cos(A1); #declare I1 = 2*cos(A1);
...

If you had both of them with "2*", you'd have a no-ripple filter with a 
2 Hz cutoff frequency. By making the first coefficient smaller than the 
second, you're making the circle more elliptical. I'm not sure precisely 
why that makes the rolloff steeper, but it's quite visually "obvious" 
why it makes the thing ripple. (At least, I hope it is...)

There's a formula that tells you "how elliptical" you need to make it 
for X amount of ripple and Y amount of rolloff. I don't know that 
formula off the top of my head...

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