The THD measurements at voltage levels 2 - 4 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 800 Hz cutoff, HPF2-800)
The THD measurements at voltage levels 5.6 - 11.2 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 1500 Hz cutoff, HPF2-1500)