I don't think digital pianos use hammers, but someone can correct me if I'm wrong.
So how would I modify the velocity curve on my piano? Should i get longer hammers?
NoSimply speaking digital piano keys generate MIDI signals in 0-127 range based on how hard they were hit. And this number (MIDI level) defines how powerful the generated sound should be.The velocity curve defines how MIDI levels are translated to audio sound levels. The curve may change the outcome a lot. It can improve the dynamic range of DP. It can make playing soft easier, for example. Also It is known that some DP never register MIDI above 120, for example, and velocity curve correction can make the sound more powerful. Modification of velocity curve is usually done in computer piano player client/library that support such a feature, such as Garritan, VSL, KONTAKT, Pianoteq, etc. Not sure any DP support it for internal sound.You can google for more detailed explanations.