The ARIA Mixer tab responds/sends General MIDI CC values. The pan knob will respond/send MIDICC value 10, and Volume Slider will respond/send MIDICC7 according to the MIDI channel that the instrument slot is set to.
Originally Posted by SecondSelf
So inside your custom sfz you'll need to add a panning control based on CC10, otherwise the instrument doesn't know what to do with MIDICC10.
Within your sfz add:
If you already have a global section just add those lines within it.
Hope this helps, good luck with your custom instruments!