Subwoofers

[Androme]

Can you use any subwoofer from a surround sound cinema kit stated to be connected to a DVD player on my PC? I just bought some Creative 550THX speakers giving my old 6.1 70W total speakers to my cousin but the bass is lacking as it's low output (24W or something).

I have a Creative X-Fi Fatal1ty with the option to connect Optical In & Optical Out along with Aux in & out + midi in & out if that helps.

Thanks all.