How come receivers today are not as powerfulas the ones back in the day. I'm talking about the old school receivers, pre-home theater, when if you had two 15" woofers and a Marantz receiver you'd make the house shake!! Now days it's all subwoofer this and amp that. You didnt need a amp back then. What da hell happened? Does anybody know why 100watts doesnt mean jack !! That wont even make my woofers move anymore... Please tell me what's going on?