altissimo on jupiter sax

i have a jupiter 889sg tennor saxophone that i have been trying to play altissimo on. i can not get any of these notes to sound. i have no problem getting them on my yas 62 alto sax. i read that some saxs want produce altissimo. is it true about the jupiter? thanks for the help.

Might be the mouthpiece?

I have a different set of altissimo fingerings for each horn that I play, then there is also the differences in air speed for the different horns.

What notes in particular are you trying to hit? Using what fingerings?

Probably the answer is in the answers to those questions, somewhere.

If it's a fingering involving the front F, the regulation of the horn in the front F key and upper stack could well be a factor.

In theory, if you can sound the fundamental, you should be able to sound its harmonics by altering airstream and to some degree embouchure (although psychologically the right way to think of it is probably purely as a function of airstream, for best technique, I guess). This is because basically the wave and the reed are working in a similar way to a string instrument, with the fundamental's sound wave being divided first into halves, and then thirds, fourths, fifths, and so on. If you can get the fundamental, you should be able to sound harmonics.

If your low Bb articulates readily, you can try playing overtones from the low Bb

It doesn't really matter on a jupiter. I had a capital edition tenor and I could hit the altissimo easily with the stock mouthpiece and a vandoren 3 or 4 and sometimes 5