I understand that RMS is the continuous power output of a unit but what I don't get is how much power it is actually pushing out and how loud the capabilities are for that receiver / headunit. I've been doing my research and was hoping someone can give me some examples of standard cheap headunits, medium headunits and some powerful headunits (so much that the car 2 cars down from me can feel and hear the base and vocals). I only need these examples so I can understand without previewing them at a store and potentially getting suckered into buying something I don't want.