I think Mercforhire suggestion is more likely the culprit.
When CAB are totally shot, it's not the sound that will alert you the most; It's the ride quality. As I've mentioned I've replaced control arms and bushings on my previous e46. This is different.
The sound sounds more like "ding", as if metal touching another metal but very hollow and light. I'm suspecting that spring, either hitting something or the bearings like Mercforhire suggested.