The THD measurements at distance of 315 mm and voltage levels from 2 Volt to 4 Volt were carried out with High Pass Filter "on" (2nd order Buttreworth type, 50 Hz cutoff, HPF2-50).
The THD measurements at distance of 315 mm and voltage levels from 5.6 Volt to 11.2 Volt were carried out with High Pass Filter "on" (2nd order Buttreworth type, 80 Hz cutoff, HPF2-80).
The speaker before the measurements had been good broken-in.