Yeap spawning requirements and timing slightly different for crappie than White bass. When you can sometimes catch them together and can catch both in good numbers is when the body of water has a shad hatch and the fry have reached about an inch or so long.This is a delicacy for ALL fish,they will seek them out and target them specifically. FIND THOSE spots where fry concentrate and the areas that the fish use to drive them to to help catch them (rock,grass beds,weed beds,rip-rap,islands,brushy shorelines.) They will also target them in open water at time driving them to the surface. They eat shad of larger sizes of course but they can be spread out over the lake and the fish can remain more separated at times. The fry rings the dinner bell for all of them and they will seek them out.The fry not having the speed of the larger shad have to find an area to help them evade the predator fish.