The THD measurements (315 mm) at voltage levels 2.83 - 8 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 80 Hz cutoff, HPF2-80)
The THD measurements (315 mm) at voltage levels 11.2 - 16 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 120 Hz cutoff, HPF2-120)
The THD measurements (20 mm) at voltage levels 5.6 - 8 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 50 Hz cutoff, HPF2-50)
The voice coil current HD measurements were carried out with High Pass Filter "on" (2nd order Butterworth type, 50 Hz cutoff, HPF2-50)
Before taking the measurements the speaker had been very good broken-in