I came up with a vent size of 4.77" diameter with .75" length

thanks
craig.

What tuning freq. are you shooting for?

Are you tring to pi align them or just go for b4?

Bill W.

4.75" diameter and 0.75" long is suitable for a Kilomax 15 in a 7 ft3 box. That should tune it to about 38Hz, which is right where you want it to be in a 7 ft3 cabinet. I also calculated 5" diameter and 1" long, which worked out the same at 38Hz.

Wayne