Hello, I'm new here and had a question about the Sony HT-DDW840. I have it hooked up to a Toshiba 65" wide screen t.v. and a Apex AD-660 dvd player. I bought this system (the HT-DDW840) a few months ago and have been pretty happy with it. Lately though I have been wishing for more bass, as some movies at loud volumes tend to overwhelm the subwoofer included in this package. Now I realize that since this home theater package was only $400.00 that it will have limitations but I was wondering if I could perhaps buy a larger sub, and if so would that help? Or should I look for some other factor other then size? I'm guessing that most subs have the same connections so they should work with my receiver. Has anyone ever upgraded the sub with this unit? If so I look forward to hearing how you made out.