C = 1.5uF (series)
L = 0.47mH (paral.)

LPad (without it, it will be to loud)
R1= 1.5 Ohms (series) NI
R2= 20 Ohms (shunt) NI

or a little less damping (about +1dB)
R1= 1.0/0.6/ Ohms NI
R2= 20 Ohms NI

Note: This is assuming that the driver output is linear and sensitivity is the same between speaker drivers.
This is not final. Wayne?
Good luck!