I don't know a huge amount about stereos and I have a few questions. I just bought a very lightly used M&K 150 THX system from the late 90's for $500. The speakers sound amazing but the sub has a rattling sound coming from one the woofers (it goes away if I apply light pressure to it). Would that be cost effective to repair? If not what would be a good replacement? (room is 4400 ft^3) Also, I do not have an adequate receiver. What would you guys recommend, music is just as important as movies if not more so. My budget is a meager $2500. Thanks!