Well, ~25% per cone could be a differnce once you start to multiply them. Sure it could all add up, but for the average consumer, having a 10" square driver vs a 10" circular driver, the difference would be less then 25% and likely not audible, tuning the enclosure / raising net volume would be more noticeable And were not even talking about the actual sd of the driver, this number varies from model to model. And by your standards of gaining more output the driver could just have more xmax and thus more displacement. But theirs a limit to everything and a point to where it's not worth it, everything has it's trade-offs I guess all in all, its just not worth it? I personally would never use a square driver, even if ssa made it, period.