The speaker makes many times the difference the amp will. It is possible to get a very good idea of what a sub will sound like if you have the right specs. These are pretty much never listed for HT subs though. I know of these specs, but I'm not an expert on reading them. Just trying to guess by things like amp power, manufacturer rated frequency response, and how the sub is put together (ie ported, downfiring, etc) is next to useless.