5.1 or 7.1 Speaker connection to Alienware 17 R2 with Graphics Amplifier or direct

I currently have my old Logitech X-530 5.1 analog speaker system hooked into the headphone out port with minimal success. The right front, center, left front and sub work in a stereo emulation but the rear set of left/right do not work. I had to use a 3.5 (headphone out) "Y" cable to an old 5.1 Logitech adapter (RCA to 3.5 black/orange/green) to get this to work. How is one to connect external speakers to this laptop? Manual says to use both headphone and microphone out ports to achieve...

5.1 or 7.1 Speaker connection to Alienware 17 R2 with Graphics Amplifier or direct

5.1 or 7.1 Speaker connection to Alienware 17 R2 with Graphics Amplifier or direct