I am having a little trouble here. I can record and monitor regular guitar/  mic inputs. I can record spdif signals as well through the spdif in of my komplete 6. I can't seem to monitor spdif signals though. They show up on the meters in my track, but aren't making it past there to either master bus or main outs. I select spdif in stereo as my input sourceand use master as my output( it uses Main1/2 output) I have tried pressing monitor on complete and leaving it out.I think I have it set up right. I'm not a noob, but I am one to NI Komplete 6 and just migrated to X2.Anyone with spdif experience out there please chime in.I don't know if it's me Komplete or X2 or a combo of all.spdif is treated like an aftertought in the NI komplete6 manual 

With my Tascam interface you cannot hear the SPDIF signal in the monitor and headphones. Only the analog inputs. 
I guess it's because the SPDIF bypasses all the Tascam's analog circuits, so they would have needed to have added another D/A converter. 


PS there's a forum for the x series this is for the older versions of Sonar. It's not very clear by the title but they will never change it.