My daugther is in the 7th grade band. She plays a Yamaha YAS23 alto with a Claude Lakey 5*3 mouthpiece and Vandoran 2.5 reed. She has a hard time doing the low notes. The band director says she may need a different mouthpiece, but he does really know a lot about the sax, he's a trumpet player. I read below about the "warm air from the diapram" which she said she has done that by accident and it worked. My question is, would a different mouthpiece help her. She has tried the stock one that came with the sax, but doesn't like it at all. Thanks.