I have a cheap ($150) Kenwood sub that I bought a few years ago and now that I have upgraded my other speakers I am ready to look at the sub. This sub sounds pretty good for music but bottoms out for low freq. movies at moderate volume. Since I can get another one to add base for movies pretty cheap is that a good alternative to buying a bigger/better sub and just having it do the work vs two cheap subs? Anybody tried this and got an opinion?