I recently took my horn into Paiges Music for my yearly cleaning. Since it will be there for quite a few days, I just practice with an old junker horn that's at least 15 years old. While I was there I bought a new mouthpiece, the same size, the other one was just getting old and nasty. Both are a Bach 3C, but I've noticed on the new one I get response issues sometimes in even the mid register. I tried drinking some water, I did 8 breath attack quarter notes on a low C, all the way down to F# and then back up to low C, 8 breath attacks on each to try and gain response back, and it helped for about a minute. This confuses me because the mouthpieces are exactly the same, one is just newer. Any thoughts?