Agree with tmppfisch, if you're descending below LSALT or MSA you're either on a DGA, Vectored, Instrument Approach, Thirty miles by day VMC or Circling Area by night (or PAPI)
If you're on the DGA or Instrument Approach you need to comply with the speed limits for the category you're operating to. It's not possible to drop down a category, but you can go up one if the approach allows (accepting the higher minima, and higher initial and final speeds).
If you're not complying with the above (ie descending early, outside the circling area, or busting speeds on an approach), you'll potentially hit cumulogranite.
You as the pilot are also responsible for terrain clearance once you descend below MDA/Circling Height. Just because you descend at the normal point on downwind/base, or even continue from the straight in approach does not mean you have adequate terrain clearance.