How do I make a single port 2.1 system subwoofer?

[Cheftoad]

So here's the thing.

I have to make a 2.1 stereo speaker set for my Year 12 major project. I've got everything basically figured out, however I cannot find what I need to do to connect my subwoofer to the system.

I think I'll have to connect the sub to both speakers, so the sound isn't only half connected to it. Should I get the lowest frequencies from each channel, put them together to make a mono sub channel and connect it that way? If so, what would I need to get for this to not short out?

Any help would be greatly appreciated.

Cheers.
Cheftoad.

[Cheftoad]

Never mind, I just found out that Subs have L and R inputs inbuilt.

Gosh, that's embarrising. :/