How to determine enclosure frequency

[thebiggmann12 14]

it only works for slot ports tho.

[CrownVic 15]

Ok so i figured out these dimensions that give me a tuning frequency of 33.5hz A volume of 3.97 cubes after subtracting sub displacement, and i think that the RE calculator automatically subtracts port volume.

Another question is are the measurements i input to the calculator Internal or external?

Anyone have experience with this calculator that can answer? Thinks alot for the help.

[KU40 173]

download winISD. It tells you dimensions needed for either slot or round ports.