MJK tables, TL size in a MTM configuration

[teodorom]

Hi all,
given the MJK formula
S0=ro*c*Sd^2*DZ*DR*Re/(BL)^2
for the size of (one) line cross-section (the other one is SL),
given the change
Sd->2*Sd
Re->Re/2
when the loudspeakers are mounted in parallel, we get
S0->2*S0
Given the MJK tables for a single W18EX001 we get
S0=347cm2=54in2 (appox)
However JdA for his Thor (S0/SL=2) uses S0=62in2 (approx), for a MTM configuration (two W18EX001).
I'm doing something wrong, I'm sure. But where ?
Thanks