10 years ago by
A Pianist
If you're hitting speed barriers, you need to go back and work out the "bugs" in your playing. Figure out where the difficulties come from. What notes of the studies tend to get shortchanged? What intervals feel awkward? Does the whole thing feel awkward or do you notice things, slowly but surely, crumbling as you progress?
Play VERY slowly (without metronome) and experiment with new motions that are more efficient and less effortful. I can't give you any specific pointers since I can neither listen to you, nor see you play, nor have you given us any details other than that you can't play as fast as you want to. So you'll have to experiment with some new movements on your own. Truly master the new motions at a slow tempo, and you won't even need to incrementally increase speeds with a metronome. You'll find that, when you discover a good technical approach, it carries with it a sort of 'potential for speed' that is apparent from the start. If you don't feel that potential WHILE you are practicing slowly, you won't attain rapid speeds.