no u got it wrong...
if on a weapon..the ed effects the base damage..ei:
100 base damage + 40%ed = 140 damage
now that 140 damage also goes through your dex/str to get even more damage
so that 140 damage sword = around 2-3k damage
but the ed on armor DOESNT go through str/dex..it just adds that damage on

so 160/60 armor adds 160ed onto the end results