I've tinkered with this stuff before. What I did was get a 12vdc to 120 vac adapter.
What you might consider is going to a trade day or something and trading the amp/woofer for something to utilize 120VAC. As was mentioned, that subwoofer (even setting aside any crossover) is not designed to play full range. So, all you will probably get is....bass.
Those little bookshelf stereo systems are fairly inexpensive these days, and give pretty good sound. Like I said, you may can trade your auto audio equipment for it.