Ok, I've been taking look at and listening to the various options for speakers out there. I have a couple of questions: Is a sub needed when using floorstanding front speakers, or only with bookshelf speakers? I suppose, if it is possible with a receiver, one might be able to use a crossover with floorstanding speakers to cut out the real low stuff. I was probably going to get something on the lines of a Yamaha 5760 or Onkyo 601...are those receivers capable of doing that? Thanks!