Since you posted in the X1 /X2 forum, I'll assume you're using X1 or X2. Try this: In the track header, locate the horizontal blue bar labeled "Volume." Click on it and drag it to the right. This will send a MIDI Volume message to your synth, causing it to play louder. You can also try this: In the Piano Roll View, Zoom out until you see all the notes in a track. Be sure you can see the Velocity lane, below the note pane. Select all the notes by drawing a marquee around them. Zoom in so at least one note is long enough to see individually. With the mouse, hover just above that note til the cursor becomes a little pencil with some bars next to it. Click and Drag up to increase the velocity of all the notes you've selected. This will increase the loudness of all the notes, and it may change the timbre of the notes to some degree. You could also turn up the volume knob on your synth when you render the track to audio.