Hi kellyboy1,
go to "Keyboard/Joystick" window (as described in my first post) and set "Touch Curve" to "Soft 2". This setting produces a relatively high volume even with light playing strength.
You can also set this behaviour separately for each Voice (using "Voice Edit" > "Touch Sensitivity", as mentioned above). Note: Since you cannot overwrite Preset Voices you must save a changed Voice as a "User Voice" then.
P.S.
If you feel that the Voices of the Keyboard Parts (Right 1 - 3, Left) are "too quiet", simply set the STYLE volume to a slightly lower value (e.g. from 100 to 90 or 85) and then increase the master volume if necessary. If you use commercial MIDI files, set the Song Volume to 60 ... 70.
Also check the Master EQ and Master Compressor settings (accessed via the mixer): You should not set too much compression, as this makes the output signal quieter. As a test, you can also switch off the Master Compressor completely. With the "Output" control of the Master Compressor you can increase the overall output signal. But please don't turn it up too far, otherwise internal digital distortion could occur.
Best regards,
Chris