Can a home audio system subwoofer be used on a computer sound system?

There are a couple ways you can tackle the problem, depending on what kind of connections are available to you.

If you have an optical audio output, you can connect it to a receiver, connect your sub to the receiver, & away you go.

Alternatively, some mobo's have analog mini-jack outputs for 7.1 sound. Find the mini-jack line output that is for the Center Channel/Subwoofer. Get a stereo mini-jack to RCA cable long enough to reach your sub, plug into your sub the RCA end that corresponds to the Subwoofer output, & away you go.

Hope this helps.

I'm also interested in this, but I don't think I have an optical audio out. Will a standard 1/8" headphone output do me any good in hooking up an external amp?

You need only Mini jack to RCA cable into your receiver. Optical out would be nice way to go if possible but rca will work. speakers/sub connected and away you go.

http://www.amazon.com/Dayton-3-5RCA-.../dp/B000F7TAA4

That's actually what I have right now I believe and each side of the RCA is going to one of my regular computer speakers (Rokit 8's)

Is there any way to split out another signal for the sub?

If your mobo only has one 1/8" mini-jack output, it is only for stereo output. Therefore, you would need to use a 1/8" mini-jack to RCA cable to connect to a receiver that outputs to your speakers + sub, as Sherardp suggested above.

Alternatively, you would need to get a soundcard that has multiple analog outputs. Then, use a mini-jack to RCA cable to connect to your L/R speakers & another mini-jack to RCA cable to connect to your sub.

Sure you can.... there are a bunch of different ways to do this, but best with an outboard USB sound card..... I like the Behringer UCA-202, inexpensive, low measured distortion and good FR. Works out of the box with Vista... not many others do, requiring you to download drivers.

Had a Tascam US-144 connected to my laptop, but it had a nasty habit of dropping audio momentarily when you have the wireless enabled on the laptop. The Behringer does not, it uses a windows built in kernal module.

Behringer is $ 30 at most places, I also bought a powered extension cable of 16 feet, so that I can have the laptop at or near the listening position. The USB cable that is built into the behringer is fairly short.

Optical output is nice.... and there is the standard RCA outputs as well. You can also record audio with the unit through the RCA inputs.