I am trying to determine if there is some way to adjust the velocity or volume of one side of the keyboard differently than the other side on the Kawai MP6.
My bass register seems too loud in comparison to the mid and upper ranges.
(Oops! I just noticed that you're asking about the MP6. My answer, given below, was written thinking you were asking about the MP7. I suspect the solution given below won't
work on the MP6, but I'm not absolutely sure about that.
I'm leaving it here just in case someone with an MP7 or MP11 wants to address a similar issue. It will work on both of those boards.)
Yes, you can do this, and quite precisely. Use the individual key volume parameter. You will need to create a keyboard scaling curve by adjusting the volume of each individual note as you wish. This is done in the System settings. Then, for any setup, choose the individual key volume settings you have created for this purpose. You can create up to five separate sets of individual key volume settings, and choose among them according to what works best for the setup you're playing.
This works extremely well. I also experienced the bass overpowering the mid- and upper-ranges (on my MP11) and fixed it perfectly using this method.
You will have to use the newest version OS to do this. Earlier versions of the OS lack this capability.