The firmware 1.4 is compatible for Mac OS hight Sierra?
http://www.denondj.com/kb/article/2360 If that is the latest one then yes.
I would possibly try and avoid going to the latest firmware. I had issues (screens freezing and other random) and it seems my issues also tie back to others that have all updated to the latest firmware. I am trying to avoid going to the new firmware and staying at 1.4. BUT 1.4 is NOT compatible with Sierra and High Sierra. If you update to 1.5 it will work. I am just to leery of updating myself.