Depth Jump Question

One of Mike Robertsons articles said that when jumping, you should try to land as softly on possible. When I do any type of jumping exercise, I try to do that. I try not to make any noise when I land. To do that I need a fairly deep knee bend.

However, I’ve noticed that when I do depth jumps, the first landing is fairly quiet even though there is a lot less knee bend, then after I jump , then second landing I have to have a much deeper knee bend to land quietly. Why is it on the first landing I do not need a lot of knee bend to be quiet, but the second landing I need a lot more knee bend to land quietly? I use a 19’’ box and rebound to a little higher then the box.