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 Buttreworth type, 500 Hz cutoff, HPF2-500).
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 Buttreworth type, 800 Hz cutoff, HPF2-800).