The 815MT are actually harder tension than EJ46, but they don't feel like it. They are, at least to my ears, rounder and sweeter sounding, while the Daddario's feels more punchy, midrangy and harder. Depending on guitar of course.
1963 - José Ramirez (A.M, Antonio Martinez)
1964 - Masaru Kohno No.7 (Kono)
1989 - Antonio Marin Montero (Bouchet)
2017 - Tobias Braun (Santos Hernández, 1924)
Feel free to ask me anything about Japanese classical guitars.