This is a complicated question as it can be many causes going from construction to previous installer damage. For the most part a factory cushion on a pool table should play as fast as any other from that manufacturer with the same cushions and cloth on it. You will see variation in rebound speed between brands and with different playing conditions. The largest factor in the speed of your pool table is the condition of the rubber cushions. A dry-rotted cushion can literally turn to powder as it breaks down, the speed of rebound can be near zero in extreme cases (see photo gallery!). When replacing the cushions I have found good success with the standard grade cushions, though I can install anything you want from Brunswick Superspeed to Artemis no 66 for more serious players. Another common cause for slow rebound is the nose radius of the cushion (where the ball strikes) is too high. If it is too low you will hear it bouncing on rebounds.