Windows 7: How to get all four spkrs to play the same frnt output in a Realtek?

I have a Realtek ALC662 driver version 6.0.1.5473.
I have two pair of same 2.1 speakers,
I used to double click the ports' icon to assign them the same front speakers' output on my earlier intel motherboard, but I had to get it changed,
Now I have some motherboard named jetway or something like that, but in this I can use the same old driver, so what my point is, I think the sound card is similar on both those two mb's.
But in the new mb I just can't double click the ports to assign the same front output.......
Help Me I tried to use the "SRS Audio Labs' Dolby plugin" to use the 4.0 to get the same playback on the all four speakers but only the front speakers play it well, rear ones sound like some underwater sound effect.
I even tried to use the Y cord/ splitter but all I get the reduced output and a drastic decrease in the bass (The mid and high frequencies play, um...OK but not as I need them to play).
I just want someone to suggest me something that can get the effect of the "Double click to assign"