I had a good sound in high school too, and it was actually a pretty mature sound. That doesn't mean that there wasn't room for improvement, nor does it mean that there was necessary anything lacking in it either. It simply matured and got better as I played more and got more experience. I'm very much of the belief that with a high school kid, the LAST thing you want to start jerking around with is the mouthpiece when a much better alternative is to examine what's going on with the current gear. I'm also not a proponent of the oft held (and just as often incorrect) assertion that switching to a bigger mouthpiece is the key to getting more resonance. Better focus and better usage of air gives you more resonance. A Monette B6 compares to a 3C - unless our young poster here has plump lips, this mouthpiece should be plenty big enough to get a resonant sound without having to go bigger. I've seen plenty of kids' chops hosed up from trying to move to a bigger mouthpiece than they were ready for.