Kenjit
NO. A Designer knows what he wants before he ever puts pen to paper. He doesn't need to try caps in crossover, he knows what values equal a given result. You really believe speakers are designed in a hunt and peck fashion? A designer may adjust a few things if they don't work precisely the way he thought, but there is no "tuning like a piano". The only way this trial and error method of creating something happens is if the builder/designer is completely untrained and is fishing for some combo that "works" by ear. This is NOT how modern speakers are designed - not in this day and age of klippel and CAD.
Studio people work for the music creators. I can assure you, because I know them and visit them/talk to them, the engineers that work for people like Tom Petty or Pink Floyd spend many many hours getting the sound just right, so the artist is happy. It must sound amazing or they are fired. Unless you want to make some ill founded argument the artist doesn't know what he or she wants, or some other equally inane argument that the artist wants their mix to sound bad, these engineers spend enormous time just getting the sound to be right. You absolutely have no idea what you are talking about. Stop confusing people with this made up crap, pretending you have some special insight.