Yes you can. Just plug the 1080 line outs into the Akai line ins. As you are playing one MIDI to 1080 track at a time record it into your DAW: in Sonar that is called live bounce to track. Repeat for each MIDI to 1080 track. I'm sure a RealBand expert can show you how to do it in RB. Mute or delete your MIDI track: PS-always work with a copy, that way you will not lose any of your work. Now your MIDI track audio is just like a RT. You can now either burn the song(s) to a CD or use your DAW to play your backing tracks.

I hope this helps and good luck.

Whenever I get something stuck in the back of my throat, I dislodge it by drinking a beer.
It's called the Heineken Maneuver.

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware