suspension noise

I have a 1999 Protege with a nagging front suspension noise problem. I've had the struts replaced and the broken sway bar links have been replaced. When the car goes over anything that makes the suspension work a bit (like the dip at the end of a driveway ) especially when more than one person is in the car it makes a substantial scraping noise as the car bottoms out. It doesn't appear to be the tires. Could it be the springs?? Any ideas? Thanks!!