I was finding the Pro X spring along with my hi-hat stand spring to be pretty stiff so I tried a longer but looser spring I found at a hardware store (I also found the spring that comes with the pro x to be kind of short, and when I set my top hat a bit higher up the rod it makes a lot of noise as it comes into contact first with the spring and then with the bottom hat).
So I swapped out the spring, and also stuck on some foam pieces on three areas of the top hat to cushion the closure. Turns out the spring I bought was just a hair larger in diameter and it was not seating properly down into the mechanism, it was giving me sporadic chicks and weird results overall. I think if I could twist it enough to decrease the diameter of the bottom end it may still work but I ended up putting back the original spring. But the closing/chicking is a bit quieter than before because of the foam. Next I'll try to add a piece of thin flat foam on the top hat strike area to quiet that down. I tried using the original hat but wasn't happy with how it sat or contacted the bottom hat so I put back the loud Pro X bottom hat.