The SAM2LF is rated at 92dB sensitivity, the SAM1HF is rated at 98db sensitivity, and the S1S-EX is rated at 97dB sensitivity. That's pretty competitive.
It must be the LE14H-3 that drags the figure down in the 1400 Array.
It's a nice stiff, heavy cone, the last of the old school drivers.
The LE14H-4 gains a few dB of efficiency at the expense of the bottom octave and a half.
I'd sure like to see some side and rear shots of one of those Synthesis 8 drivers.