I gotta tell ya, I don't give a sh!t about Home Theatre Surround Sound, but the sub-woofer thing ( when set within reason) is maybe a different story. So, I'm considering maybe adding a sub-woofer to my very old school home stereo system. Which is a 1977 Kenwood Integrated Amp and a pair of (same year) JBL L-40 2-way Bookshelf Speakers. Can this be done (and how), and what do I want to get? I'm talking listenable, moderate ( at the most ) amount of bass. Not this overpowering tear the house down, vibrate cars off the road crap. For some reason Klipsch comes to mind. Tell what ya think. Many Thanks.