Well I guess I did not state this, but I don't have T/S parameters either. If I did, then there are many tools to help calculate this.
I will gladly accept T/S parameters for the LM-12 as well.
Any info is appreciated. BTW, I have searched on here as well as the greater web with no specs found. The Illusion Audio website seems to be long gone.
Found this list with a bit of google magic- no idea if it's accurate:
P/N Size VC Type dB W Z Re Le Ce Fs Vas Qms Qes Qts Xmax Cutout
AUDIO HIFI cm mm 2.8V mH F Hz li mm mm
LM-12 32cm 50mm Poly Cone 94 250 4 3.7 .37 27 25 91 .30 ±15. 282
ND-12 32cm 75mm Carb Cone 96 400 4 3.4 1.0 82 26 102 6.2 .28 .26 ±15. 282