Yeah, there are a handful of things I would check if it were my own car, but a ball joint would be the first with how you are hearing the sound. It could very well be the strut rod, not to sure how it could cause it to knock more than before, though. Perhaps the bushing was moved by the impact and now the rod is riding on the hole in the subframe instead of on a bushing?
Here's what I would check:
All hardware on the control arms
Shocks
Strut rods
Wheel bearings (unlikely)
Sway bar end links (if applicable)