Reply to 1/4'' Outputs and cables and mono signals

Hey folks

So i recently picked up an Akai EIE Pro and a Behringer DDM4000. The Akai has 4 balanced 1/4'' outputs that supposedly output a stereo signal.

My problem: I can't get the either the soundcard to output a L/R signal no matter what configuration I use OR the cabling set up properly. I've read both skimpy manuals and scoured the interwebs for an answer with no luck. I have a feeling this is just my incorrect choice of cabling. Right now, outputs 1 and 2 have 1/4'' TRS cables with a Y cable (1/4'' to RCA) adapted plugged into inputs 1 and 2 of the mixer. I only get the left side from both channels. If I've read correctly, both cables should be sending a stereo signal that split left and right by the Y-cable.

Is this an issue with the soundcard? Or should I be using a 1/4'' TRS that splits into L/R TRS cables with RCA adapters on either end?

Feel free to call me an idiot, as that's what I feel like right now.