http://www.teac-audio.eu/en/products/ag-d200-87833.html?tab=Details In "technical details"...go down to "other features". First thing listed are your crossover choices.
I don't have the slightest idea "how" you bought a 1/8th-RCA and a splitter. You only need the 1/8th-RCA. Then it is a matter of determining if the white or the red is sub vs center. On top of that, it also matters what frequency response the Logitech even has. What it is "bottom"? Is it lower...