using mpc to trigger vst instruments: switching octave range

I can get the mpc to trigger my software samplers (proteus x, pro 53,etc), but I can't figure out how to change the hi lo key so when I play the software samplers off the mpc, It only plays the high notes. I wanted to try and play out a bassline with the mpc. I've tried looking in the software sampler to see if there's a way to do it but I can't figure it out? Anyone have any suggestions?

did you try changing the notes of the pads to the notes you want to play?