with RB you can hear your live input and the backing and there is a facility to use fx on the input sound. at least i think i'm right - it certainly works with vocals when i use my behringer audio interface. i can vary the mix of backing and live on the unit as its full duplex.

forgive me because i'm not a sax player but when i sing i get my input played back to me but 'hear' my voice anyway

are you likely to hear the reverb from the input over the loud live sax playing?