I have both the (S4's) and the (x10i's) and the (x10i's) do use the armature drivers and the (S4's) use the micro drivers. Well believe it or not I like the (S4's) better and as far as the extra money paid for the (x10i's) I feel it doesn't justify all that extra cost over what the (S4's) can deliver. I like the (S4's better!!!) While the (x10i's) might have a better overall refined sound through the frequency spectrum the (S4's) definitely, yes definitely have more bass thump or more bass period! Professor Thump new what he was talking about when he said the S4's definitely have more bass. I much prefer the (S4's) over the (x10i's) hands down! []