Yes, I know.
You mean I = V/Z.
The phase of what?
And why does that matter? Whether you drive the headphone from a current source or a voltage source, for a given current through the headphone, you'll have a given voltage across the headphone. I = V/Z, V = IZ.
Yes, just as voltage is a function of current.
But the impedance of an ortho, such as the LCD-2, which is what this thread is about, is virtually purely purely resistive. So you may just as well use R instead of Z.
As I said, the LCD-2sare virtually resistive.
And even if you are talking about a resonant circuit, at resonance, phase is 0 degrees and Z is purely resistive. You only get a 90 degree lead or lag when the load is PURELY reactive, i.e. pure inductance or pure capacitance. When there is any loss, such as resistance, the lead/lag will always be less than 90 degrees.