Sonar x1 and A&H ZED R16

Hi guys.I have written a midi arr't which is recorded in sonar(in midi) I am playing back using a tyros via midisport into desk.I want to record a vocal track but each time I try the signal from the miditrack which ive routed to chs 1 and 2 record also.Can anyone assist please!I have the mic in ch 16.