I'm not sure what you mean.  I was just remarking that a purely capacitive load does not consume any energy, so it cannot give an entirely satisfactory electrical model for a device that moves the air around it.    I don't know anything about what it takes to model electrostatic headphones...

It can't be perfectly capacitive because there would be no transmission of energy.  But perhaps this imperfection shows up more as phase deviation than as magnitude deviation from the ideal 1/f.  After all the membrane should transmit energy rather evenly at all frequencies.   But it would...

This is a great thread for information.  Voltage, current, slew rate...  now what about what's at the other end ?  I've never seen an impedance curve for a Lambda or an Omega.  Surely such data must be available somewhere.  We know it's essentially capacitive, but are there surprise dips here...

Are there common uses for high voltage bipolar transistors other than CRTs ?  In other words is this a technology that's likely to disappear, as is happening with so much analog now?  But you probably can design good estat amps using high-voltage MOSFETs.