Bari Sax seems broken, can't play low notes?
Hm, I had a problem with playing the high notes one day, because one of the keys wasn't closing all the down, so there was a small space that the air could escape. Also it could be your embouchure, reed or your mouth piece. Just try fiddling around with the mouth piece and reed and changing how you blow, and if nothing works Google is your best friend. And try going to a music store and see if they can tell if anything is wrong.