Q:
... when I attempt to map the Input Routing in TRAKTOR PRO to my Xone:4D, I only see 'MASTER IN' as the options in the dropdown.
This is the same as the output routing (I only see 'MASTER OUT').
What should my settings be here?

A:
In Mac OSX, Traktor Pro will recognise all Xone:4D soundcard INPUTS and OUTPUTS as MASTER IN (1-10), and MASTER OUT (1-10) connections.
These relate, sequentially, to each of the XONE:4D soundcard inputs or soundcard outputs, so that:

1: MASTER IN = XONE:4D INPUT SC1/2_1
2: MASTER IN = XONE:4D INPUT SC1/2_2
3: MASTER IN = XONE:4D INPUT SC3-4_3
4: MASTER IN = XONE:4D INPUT SC3-4_4
5: MASTER IN = XONE:4D INPUT SC5-6_5
etc
and
1: MASTER OUT = XONE:4D OUTPUT SC1/2_1
2: MASTER OUT = XONE:4D OUTPUT SC1/2_2
3: MASTER OUT = XONE:4D OUTPUT SC3/4_3
etc

The Xone:4D digital (SPDIF/OPTICAL) inputs/outputs listed in the Traktor Pro Input Routing / Output Routing preferences as:
9:MASTER IN / 10:MASTER IN
and
9:MASTER OUT / 10:MASTER OUT

The Xone:4D Soundcard Inputs or Outputs can be assigned any of Traktor's Decks (A, B, C, D) as required.
Please note, however, that if you are not routing external audio, or encoded vinyl, signal source into Traktor Pro (i.e. when you only use audio tracks stored on your computer system), that we recommend leaving Traktor Pro's INPUT Routing options set to "not connected" (and ensure that each of the Traktor's decks used is set to "Internal Playback" mode).

If you require any further information or assistance, please contact the Allen & Heath Technical Support team at: http://www.allen-heath.com/support