Thanks all for the responses! I don't think I expressed my question correctly. Empirically, is there a sweet spot for thickest/best sound at a home level? I know that to get louder you need more watts and more speaker surface. At a lower level, is the best setup a lower wattage head with a single driver, or is it more power and more speakers? That is ultimately what I am trying to understand.
Based on the response, I don't think we know. I know that amps have volume knobs. I know that you can get a rig to play out with, keep up with a drummer, bother my neighbors, etc....that is not what I am asking.