I just took delivery yesterday on a set of Swan Diva 4.1, C3 Center and R3 surrounds. I have a Hsu VTF-2 sub on the way as well. My current receiver is a Sony STR-DE925 that's a few years old. Do I need to look at upgrading this. These are the first set of "real" speakers I've ever owned. Previously I was mixing fronts I got for free with Boston Accoutics center (VL7 I think) and BA Micro Dipole rears; so this should be quite an upgrade and I want to do things right this time. If I need to look at upgrading my receiver soon, I'd like to keep it below $500. All suggestions and help are appreciated.