Quoted:
When you guys say behind, your talking about Soft Armor against the wearers chest? How would that prevent spalling if the soft armor is BEHIND (thus being against the wearers chest) the steel plate?
I have the steel plate against my body and then the soft armor in FRONT (not against my body) that way it would prevent spalling.
The first animation (grey plate) is an example of spall. The force of the impact "pushes" off chunks from the back of the plate, even though there's no actual penetration. A stand alone plate isn't supposed to do that, but an In-Conjunction-With plate might. The soft armor is enough to catch the spall.
What you're talking about is the fragment of the bullet breaking apart.
That's this:
With steel armor there's no built in mechanism to stop that action, and it can easily cause serious harm to the wearer.
All of this is why I wear ceramic armor.