Audio routing for 2 x NDX900s and external mixer

Ive recently purchased 2 x NDX900s with Traktor LE 2, Ive followed the set up manual to the letter(except the fact ive chosen to use an external mixer) and what its resulted in is there is no audio from channel 1, deck A plays thru the left speaker on channel 2 and deck B plays thru the right speaker on channel 2
Im using-
Windows XP
Traktor LE 2 Version 20.3 (RIO893
ASIO4ALL V2

My out put settings are -

Mixing Mode -
External

Output Deck A -
L - 1:USB Audio CODEC 1
R - 3:USB Audio CODEC 1
Output Deck B-
L - 2:USB Audio CODEC 2
R - 4:USB Audio CODEC 2

Controller Manager -
Now in the device set up here it shows 1 device but with a drop down box so you can choose either Deck, i did wonder if there meant to be seperate? Anyways ...

Device - NDX900 DECK A CONTROLS
In port - USB AUDIO DEVICE
Out port - USB AUDIO DEVICE

Device - NDX900 DECK B CONTROLS
In port - USB AUDIO DEVICE 2
Out port - USB AUDIO DEVICE 2

What im hoping to achieve is basically access to music filds on the pc but to mix them in a conventional fashion in essence have the pc as big usb stick for each deck..I hope thats enough information

 

I'm not sure I clearly understand your setup so a description of the complete routing would help

A problem I can see is that you probably want one ndx900 to do the output of deck a and one to do the output of deck b which won't work this way I think.

If you're on osx you can try creating an aggregate device out of the two ndx and on windows you can use asio4all to do that, that would enable you to do what you want

 

I give up ive managed to sort that problem n created another...
Now channel 1s audio drops dramatically as soon as i select a track for deck2 and channel 2s audio stay at the same level channel 1 was