The internal damage caused by dropping the speakers generally distorts the baskets of the woofers and midranges. The heavy magnets on the back of the drivers causes the basket to bend (or break in the case of die cast baskets) and thus ruin the driver. You may need to replace all of the woofers to restore the sound.
Before you take all the of bass/midrange drivers out of the cabinet, try pushing in gently on the cones. If they make a scratching sound or if they do not move at all then they are scrap metal. If all seem to pass the push test, then try taking them out and hooking them up to an amp and playing music through them. If all of the drivers sound good, then you should suspect the crossover. The big heavy coils of wire that are usually part of the low-pass filters may have broken loose from the crossover network and are no longer in the circuit. They can generally be re-glued to the board and then re-soldered to restore the sound.
Before you take all the of bass/midrange drivers out of the cabinet, try pushing in gently on the cones. If they make a scratching sound or if they do not move at all then they are scrap metal. If all seem to pass the push test, then try taking them out and hooking them up to an amp and playing music through them. If all of the drivers sound good, then you should suspect the crossover. The big heavy coils of wire that are usually part of the low-pass filters may have broken loose from the crossover network and are no longer in the circuit. They can generally be re-glued to the board and then re-soldered to restore the sound.