L_E (L_e/(sin(n_e*pi/2)))*(acpr.omega[s/rad])^(n_e-1) Voice coil inductance (frequency dependent)
Rp_E (L_e/(cos(n_e*pi/2)))*(acpr.omega[s/rad])^(n_e)[ohm/H] Resistance (losses in magnetic system)
F_D intop((down(p)-up(p))*nz) Axial pressure force
P_AR intop(up(acpr.Ir)*nr+up(acpr.Iz)*nz) Radiated power
P_E 0.5*realdot(V0,cir.R1.i) Electric input power (rms)
eta P_AR/P_E Driver efficiency
k0 acpr.omega/c0 Free space wave number