I watch the "what size speakers should I use" or "15's vs 10's vs 12's vs 18's vs Aliens vs Predators" and it dawns on me - speaker size is the "tonewood" argument of the amps forum. Does speaker size impact sound the sound of a rig? Does tonewood impact the tone of a bass? The answer in both cases is (IMO) "yes, but way less than many other factors - and not enough to outweigh those factors." For a bass - amp, speakers, and eq will far outweigh wood choice in the sound you hear. And different pickups, pickup placement, and string choice will also have huge impact, with a host of other factors making other impacts. And two different pieces of the same type of wood can have completely different characteristics. So while it is possible to build several identical guitars such as to show the tonal difference between types of wood, in the real world that is relatively moot, and it is also possible to build several guitars to completely mask/negate/confound the sound of the wood involved. For speakers - two different speakers of the same size can have completely different characteristics. And box design will have a much bigger impact on the sound you hear than the size of the speaker, while other factors (xmax, etc etc and etc) will have huge impact, more than the physical size of the speaker. And it is possible to build cabs that make different speakers sound different, and possible to build cabs that make the same speakers (let alone the same size speakers) sound radically different, or to make different size speakers sound pretty much the same. And regardless, there will always be those who hear with their eyes, and who say "Dude, I can totally tell <insert tonewood or speaker size here> when I hear it, and I can tell the difference between <wood or speaker size 1> and <wood or speaker size 2>.