bang

I've only noticed this recently when braking suddenly or heavy braking. I am getting a loud bang/ clunk sound from what feels like directly underneath/behind the front seats. I got the rear drums changed over to discs a few weeks ago but I don't think the two are related. Any ideas what could be...

Hey, Like it says on the tin… when I stick it in reverse and begin to reverse (not all the time), but sometimes I get a loud knock, almost like a sort of loud hollow metal bang? Just the once? I think it's when the steering is on full lock or thereabouts. Any ideas what this is a sign of or...