The amplifier have 4 inputs (2 front and 2 rear) and 4 outputs plus a bridged output.
Now, u have one line coming out of the laptop, u have to split every channel into two using this "Y" channel splitter
Those 4 channels will go into the input of the amplifier.
The output is divided into front and rear. Now u have two options:
1- Connect all 4 speakers to the front and enable the HPF on the front. And connect your subwoofer bridged to the rear output and enable LPF.
2- connect the front speakers to the front output + enable HPF, and connect the rear speakers and the subwoofer bridged to the rear. U can use a capacitor before the subwoofer to act like a LPF to avoid distorted bass.
I am using the 1st setup and I'm happy with it. U can always control the gain of the front and the back separately from the ampl.
btw my amplifier is a sony xplode not kenwood. I'm using this one.