Do I need a separate amp for the SVS PB12 ISD/V subwoofer? The SVS website indicates that an amp is needed for all their subs under the frequently asked question section, but I thought this is what a receiver does (ie, I am looking at the Denon 2805 receiver paired with Axiom M60 (fronts) 150(center) and QS4 (surrounds)). If a separate amp is needed, anyone have any good subwoofers that do not need an amp (i.e., Hsu or Outlaw)? Please forgive my ignorance as I have not purchased an expensive sub before.