House of Drumming.com

Use ankle weights, work on a better/more efficient practice routine for your feet, etc Minor differences in tension, feel, etc shouldn't affect your playing much at all?
I guess the question is, why do you just notice it now?

Though you should also get your kick and pedal setup so it's not over extending the pedal as well. You'll prob find you get a lot more sound out of the kick in the process.