Disclosed herein is a golf ball with a solid core having a PGA compression of 55 or less and an outer cover layer having a Shore D hardness of at least 60, the ball having a PGA compression of 80 or less. In another embodiment of the invention, the ball has a mechanical impedance with a primary minimum...http://www.google.es/patents/US6152835?utm_source=gb-gplus-sharePatente US6152835 - Golf ball with soft core
