Only if your receiver has bass management. Then you will need another amp and an appropiately sized and stiffened box to put it in. You will need the TS parameters to build the box. Do you have those?
You can get an amp at Parts Express which would have the crossover built in, and jacks for you speakers. I'm toying with a similar project with an two 15" woofers I have lying around, and no TS parameters. Just building a big box and amping it, and hope it works (since I'd only lose the box and time - both cheap) if it did not work out.
Somewhere out there is a way to determine the TS parameters of a speaker. Does anyone know? Is other electronics/software required?
I feel another project which of course means MORE TOOLS