Stepper Mid band resonance Help! please...

Hello,

I have been trying to learn how midband resonance is dealt with by
the commercial drivers which claim circuitry solutions. I've not
found anything directly related to this on the net. (By direct, I
mean somethings which says, "Here's a circuit we use to deal with
midrange resonance and here's how it works...")

I have heard "clues" like second order damping, and filter... My
search has taken me all over the spectrum, looking at snubbers on the
yokes of CRT's (used to reduce ringing), to Zobel filters.

That zobel reference came recently from looking at speaker crossover
design, which appears to be related as it deals with inserting an
arbitrarily variable frequency waveform (akin to our CNC step rates)
into an inductive load, and the speaker also has midrange resonance
issues, due to ITS construction...

I'm self taught and up against the ropes... HELP!

Can anyone point me towards some answers or even confirm if I'm
anywhere near the right path? How is electronic midrange damping
achieved in stepper motor drives?

Thank you in advance,

Ballendo

P.S. Mariss has explained really well WHY it happens, Now I'd like to
know how to make it stop. As there are more than a few commercial
drives which claim to have solved it, I assume that on some (rarified
from my perspective<G>) level it is common knowledge?!?!?