The HD measurements at distance of 315 mm and voltage levels from 2.83 Volt to 8 Volt were carried out with High Pass Filter "on" (2nd order Buttreworth type, 50 Hz cutoff, HPF2-50)
The HD measurements at distance of 20 mm and voltage levels from 4 to 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 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