ok open cubase first then go to file new project /next select how many midi tracks you want/next open reason
you will get a box saying midi input problem just click OK /next you will get a box saying reason could not set up control suface properly click OK reason should now open .next go back to cubase and click on devices
and in the dropdown list click on reason a rewire channel should come on the screen click on the little box on the left to activate the channel keep going down to select the amount of midi channels you need and that it you are know rewired to reason . what i do is in reason i make a template that i use all the time what i do is open reason empty rack mode then add a mixer then add four effects then add redrum i the wire each channel of the
redrum to a channel of the mixing desk next i add another mixing desk add four effects the add nn19 once this is done i save it as set-up so when im working on a new project i open cubase the open set-up hope this helps if you need anymore help let me know
