I currently have logitech z560s setup and i'm using the ALSA modules, but my sub isn't working. It's the like the speakers aren't being amplified. Is there an external amp option in the ALSA mods. I need to enable?

First, disconnect your speakers and connect to a portable CD player. Are you able to hear or feel the bass from the subwoofer. If not then your subwoofer could be damaged. If your subwoofer is working then it could be how you connect the speakers to the sound card. If you are connecting your speakers using two seperate stereo headphone plugs. Then yes it could be ALSA. You may need to read the documentation on scripting for the ALSA modules. If you are using one stereo plug for your hook up and you can not hear or feel of bass then it could be your computer. Are you using an audio source with bass.

FACTS:
Subwoofers are omnidirectional. This means that it can not be heard where it is. Subwoofers produce from 220 hertz down to 20 hertz if you are lucky enough. Because of subwoofers omnidirectional characeteristics, it gives an illusion that small speakers are producing the bass. In reality the subwoofer is producing it.

Speaker drivers can be damage from noise, bass equalizing, or immediate pops. Noise can increase amplifier's wattage by several times. A 100 watt amplifier with added noise in the audio source can produce up to 500 watts. Same goes for bass equalizing. Turn down all your volumes in your mixer panel to around 75 to 90. This makes sure that your sound card will not produce distortion or noise.