I'm considering buying the Kenwood HB-405. It seems to come quite highly recomended, both here and in the customer comments on the Circuit City web site, and I don't have the money for individual components or the patience to learn about them. But that "passive subwoofer" or "non-powered subwoofer" does seem to be a minor complaint -- a few even recommended the comparably priced Sony HTDDW740 for that reason. Can someone enlighten me on what this phrase means? Edit: This probably sould have gone in the Home Theater Basics forum, so feel free to move it.