I play the bari sax, and I know every nook and cranny of it. I only have an intermediate model, but it has a low A key, and I can bend it down to a G#. You cannot go lower without any assistant.. ie. hand in the bell. Extending the bell (which you can`t) would make it not a bari sax. Bass Sax`s go down to a Concert A flat, which would be a low F on a bari. I play on a #5 reed, thought I`m sure its possible to order some harder reeds. I can play higher than altissimo D (D4), which is an octave higher than the natural high D on the bari. The general range of the average bari these days however is Low A to high F, F# is an altissimo key, but some bari`s have them included, if it is not, it is a very easy note to hit.