Is there a way of calculating the size of bass hangers?

How do you know how wide and how tall to make bass hangers? Do you just make them as big as possible when using them behind a false wall? Or is there a calculation that changes the effective frequencies?

:twisted: Big, big question mark. The problem is: I'm NOT joking ..... Hence the answer is: the bigger the better, and likely the more the better, and whatever exact relationship (linear or non-linear) exists is nowhere described. Hence copying others who did it before you (empirical) is the only available approach.