As you go through pi aling enter the following fields

description= anything you want to call it
Type= M
lo cut= 50 (if you have 70hz sub 50 would be good)
hi cut= press enter for no entry
Eff= spl 1w/1m
power= watts max
impedance= Re (4,8,16 might get you close)
quantity= number of drivers per enclosure

for pi align you need to know from the t&s parameters
Vas this will be the VAD input (must convert to Cubic Feet)
Qts 1 devided by the Qts will be the QD input 1/.578=1.7301
Fs this will be the FD input

Enclosure type= B ( for bass reflex)
Port= C / cylinder R / rectangle

you now have all the dimensions and volume in cubic feet acording to pi align.

Bill