The HD measurements at distance 315 mm and voltage levels 2 - 5.6 Volts were carried out with digital High Pass Filter (2nd order Butterworth type, 50 Hz cutoff, HPF2-50)
The HD measurements at distance 315 mm and voltage levels 8 - 11.2 Volts were carried out with digital High Pass Filter (2nd order Butterworth type, 80 Hz cutoff, HPF2-80)
The voice coil current HD measurements were carried out with digital High Pass Filter (2nd order Butterworth type, 50 Hz cutoff, HPF2-50)
Before taking the measurements the speaker had been very good broken-in
The detailed review of the MR13TX-4 speaker