you could also push your mouth piece in more when you play and just loosen you jaw when you go down in your lower notes. but I seriously reccomend going up in reed thickness a bit, it improves your sound.

If you get higher reeds and it's still a problem, then its probably your horn. I use a Yamaha 62 II Series and it blows flat in the upper register. I want to upgrade to a better saxophone like a Selmer Mark IV or the new Reference models but they cost too much. Maybe I should get a better job with higher pay? Right now I get 6.20 and I dont work that many hours during the week. Or maybe I should sell one of my organs, such as my liver or some kidneys, on the black market. I heard that you can get a decent wad of cash doing stuff like that, as well as being a prostitute. Wait....oh crap....are there male prostitutes? I mean, since I'm a guy and all..... One way or another, I will upgrade to a better horn that doesnt blow flat in the upper register.