Could Not Figure This Out!

Playing on the tip of the fingers the sound is thinner than than playing on the finger's pad? If what influences the sound is the speed of the hammer hitting the strings,why does the different touch of the fingers influences the sound? I notice the different sonority but cant understand why? I tried to think maybe its that when the finger is extended, it takes more time to actually get the key down thus the slightly "fatter" sound.....?? Thanks a lot

Aha, you have stumbled upon one of THE questions. Kemal's axiom: the greater the area of flesh coming in contact with the key, the richer the sound. Check it out; you'll see just how true it is. But HOW this happens is even still a mystery to me! AFF