linking up an s4 to 1210's

linking up an s4 to 1210’s

they are not working through channels c & d… they are playing through it but the crossfader dont work.

Are the AC/BD channels on either side of the crossfader on in the software?

i think i worked it out, i had to change c & d in the preference menu to live input. well thats what i have been told. hopefully it will work…?