A lot of all-in-one HTiB have special speaker connections so it's difficult to connect different speakers to the main unit or vice versa unless you do some wire splicing. The subwoofer is usually passive in these systems (deriving its power from the blu-ray player) so connecting it to a standalone receiver, while not impossible, may be a little difficult and the resulting sound would be less than desireable. You might want to look at another HTiB without a built-in blu-ray player because speakers can be upgraded very easily if need be and the subwoofer will more than likely be an active sub which will give you much better bass response. Then just get a separate blu-ray player and you're all set. Ideally, it would be best to buy separate components instead of an HTiB but if money is tight, you can get some very nice systems from Yamaha, Onkyo, and Denon.