For a low budget of $150 or so the subwoofer offerings from parts-express should work well along with the used Paradigm model you are interested in. From the sounds of it your Kenwood sub is on life support with the "popping' and all. Its ready for the electronics bin.
http://www.parts-express.com/home.cfmThanks for that link. I haven't heard of that site before.
I have had the Kenwood sub for about 14 years. It's in pristine shape, just failed after a while. I did have two EP350's, which didn't work out so well.
