Lowered too much?

I just bought a '94 gt. pics already in another thread. My questions is this: It's obviously lowered, I don't know which springs are in there. When I drive over a large speed bump, even really slow, the tranny cross member sometimes hits. Is this normal for a lowered mustang. Or have maybe the springs settled too much and it's lower than it should be. I've got maybe 4" of ground clearance.

If this is the way it is than fine, I've had lowered trucks and such before so I can deal with it. I've just never had a lowered car and thought I'd ask for some input.

Comments are welcome.