I've had 4 kits. Dw, starclassic, pdp, pearl export pro and now a sonor s class pro. Never have I had such a difficult time finding an even pitch on the drums. Would a change in temperature caused the shells to expand or change to a point where tuning could possibly become difficult. I can't get a consistent note very well at all. I go by tension first, then ear. It's quite difficult. Anyone else have a hard time with these kits? I miss the true pitch tuning feature.