Muffling the drums works adequately but excessive muffling makes them sound dead and constricted. Try tuning your snare drum higher or lower to minimize the interaction between it and the other drums. Also try detuning the four tension rods on the snare side adjacent to the snares until the rattle is reduced. Still having problems? Try moving your drums to a larger room and/or minimize reflected sound by adding sound absorbing materials such as rugs, furniture, drapes, acoustic tile, etc.