The HD measurements at voltage levels 2.83 - 8 V were carried out with High Pass Filter "on" (2nd order Butterworth type, 800 Hz cutoff, HPF2-800)
The HD measurements at voltage level 11.2 V were carried out with High Pass Filter "on" (2nd order Butterworth type, 1200 Hz cutoff, HPF2-1200)
The voice coil current HD measurements at voltage levels 2.83 - 5.6 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 800 Hz cutoff, HPF2-800)