As written by Jdholman:
"
When you say your velocity is working fine, I assume you mean that you have the velocity on your amplitude envelope of whatever plugin you're using (such as Omnisphere 2) turned up to respond to how hard the keys are pressed. That was my problem to begin with. I had it completely turned counter clockwise on my synth that effectively turned it off and any type of playing anything I recorded was not affected by moving the velocity stalks of the recorded notes inside the midi editor. This is what I discovered. What I don't understand is why I have not discovered this before (maybe I never had the way the velocity affects the played notes turned up, who knows). To me it now makes sense that if you have this knob completely turned off when the plugin was being recorded, then moving your velocity stalks will not change the volume of the recorded notes being played back. It's the same thing as if you were playing the notes in real time on the keyboard, no matter now soft or loud, and you would always hear the same volume. All I know is that when I turned these knobs inside the plugin on my AMP envelope on so that they DID affect the velocity, my problem was solved. As far as my configuration, I have both a Mac Pro and an HP Z420 PC workstation. The Mac Pro is Mavericks (10.10.5) and the HP is WIndows 7 Professional 64-bit. I just now downloaded Studio One 3.2 to the Mac and the effect was the same, so the operating system makes no difference from what I've found. The Mac is actually a backup machine and I ported everything over to the PC because it is considerably faster than my Mac.
As long as I have the amp velocity set right in the plugin itself, the DAW will do what it's supposed to in the midi editor. And as one person suggested, it may be that this is not always the case with every plugin. It didn't seem to be with Mai Tai. I thank everyone for their helpful suggestions but I am considering this matter closed.
related to an answer for: There is no problem like this on the instruments that come with Studio One, only third party plugins"