The THD measurements at distance of 315 mm and voltage levels 2.83 - 4 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 50 Hz cutoff, HPF2-50)
The THD measurements at distance of 315 mm and voltage levels 5.6 - 11.2 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 80 Hz cutoff, HPF2-80)