Hello tunehead! Here's a suggestion for your "adding a woofer" problem. Wherever you extra woofer is located, you only want the lower frequencies to go to it, right? So, place it in series with your existing speaker and put a large (100 - 300 mfd) capacitor in parallel with the extra woofer. I suggest you get hold of six or eight 50 mfd/200volt capacitors and put them across the new woofers terminals one by one until you find the combination that works best. No need to use expensive units at this point. Trail and error will help you refine the value of that capacitor you'll need. If the new woofer is in a cabinet already, no problem. the ground (black, negative) terminal of the new woofer goes to the amp's negative output terminal. Your existing speaker's negative wire now goes to the positive (red, +) terminal of the new speaker. The highs go thru the capacitor and the lows get left behind to move the cone of the new woofer. It will look messy for a while, but an afternood of fun will let you know what value of capacitor you need. Buy a good one, Mundorf KPR or better. The load on the amp will actually be easier than before. The final location of the new woofer will make a big difference. Contact me if I haven't explained it well enough. Enjoy the music.