I am using Reaper as my sequencer and have the ARIA player installed for JABB3, I am trying to get reaper to control the volume sliders in the ARIA player using CC#7 but it doesn't seem to work reliably and its hair pull out time.

After determining that the correlation between midi values and dB level is extremely narrow, e,g, on one channel 64 corresponds to -6, 70 to -5 dB and 76 to -4, I then tried a value of 75 on another track and it racked the slider up to full volume! it seems that there is no failsafe correlation between midi value and dB level you can apply to each track. Why cant I just assign a dB envelope from the midi track (e.g. volume or send volume) to the volume slider? that would work so much more easily. I want to get the trumpets to accent on some tracks, and the expression mod wheel just doesn't seem to cut it with a "da daaaah" effect.