measuring for the brace height

[compound_convert]

i made my first bow of ipe and a hickory backing,its 70'' with a draw of 29'' it holds up well, there is a slight more bending in the lower limb. i was told since i am a 3 under shooter that was a good thing. my question is how do u find or calculate for the brace height. does one just shoot at different measurements until the noise and vibration is at its least? any help would be greatly appreciated, thank you.  

[Osagetree]

Start at 6" and go up from there until is feels best, like you said.

[compound_convert]

thank you osage for your help