I would be looking for suspended fish over channels while using that amount of weight. You are trying to cover a lot of water at a faster speed. I would follow the channel edges watching your DF and adjust the depth to where you are seeing fish or a little below bait. Crappie will suspend near structure and channel edges are structure. Start out with bait at different depths, 4' to 14' deep and see where the crappie bite is and adjust all your rods to that depth. Try to work one edge of the channel into the coves or creeks and work the other edge of the channel coming out. Be sure to work the main channels where the creek channels meet. Channels are a crappie's highways.