Fmd
This parameter controls the mid-high frequency properties of the transducer diaphram. As frequency increases, the moving mass of the diaphram will decrease, resulting in a rising response. This works in an opposite fashion to somewhat compensate for the voice coil impedance which is generally increasing resulting in a falling response. The value is given in KA units of frequency which relates directly to the size of the diaphram. This value can be adjusted to produce a reasonably good match to the known high frequency acoustic response of the transducer.
Flp
This parameter simulates the high frequency properties of the transducer diaphram. At high frequencies diaphram size and construction results in a falling response. The effect is simulated here by a 2nd order Lowpass filter. The value is given in KA units for the relative corner frequency which relates directly to the size of the diaphram. This value can be adjusted to produce a reasonably good match to the known high frequency acoustic response of the transducer.