Great response, just had to say your statement “a headphone is a lightbulb in a crumpled can” is perfect 😂 sincerely - a headphone designer after a long day.

To elaborate slightly about the tools the various “big guys” use, there are a handful of mathematical methods you can use to predict/understand what sorts of changes to make regarding the variables of headphones, but it is quite messy. And a lot of the more boutique headphone places follow the “pole a hole and see what happens” approach. - which isn’t a bad thing, just one of many design methodologies.