Is there actual scientific evidence tension varies from brand to materials for a string of the same gauge?
I'm curious if it's true, and how much is noticeable. I've been playing for decades and have never noticed this. Not saying it's untrue. I have noticed tension differences between guitars, even the same type..I own two strats that are completely unlike each other in string tension. Just never noticed between string brands.
I was going to reply with an unequivocal "No," but then I did a little Googling. Found this tidbit on D'Addario's website.
"String tension is determined by vibrating length, mass, and pitch. The string diameter alone does not determine a strings tension. By using different raw materials (nickelplated steel or phosphor bronze, etc.) or by varying the ratio between the core and the wrap wire, two strings with the same diameter, tuned to the same pitch, could have two different tensions."