The THD measurements at distance of 315 mm and voltage levels from 2.83 Volt to 16 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 80 Hz cutoff, HPF2-80)
The voice coil HD measurements at voltages 2.83 - 5.6 Volt were carried out with High Pass Filter "on" (2nd order Buttreworth type, 50 Hz cutoff, HPF2-50)
The voice coil HD measurements at voltage 8 Volt were carried out with High Pass Filter "on" (2nd order Buttreworth type, 80 Hz cutoff, HPF2-80)
Before taking the measurements the speaker had been very good broken-in