You definitely need to try different depths. I usually start about halfway down and then move up a foot or two at a time. Then drop all the way to the bottom and work up after letting it sit for a while. Using a two pole stamp you can do this faster. Also, you said plenty of bass? LMB? My experience has been that if the largemouth move in on the baitball, the crappie bite slows drastically. Meaning, if I start catching several LMB, I stop catching crappie.