2nd order tuned box? height of pipe from base tuning loudness? are u sure u know what u are talking about? in any case atleast a port diameter is recommended as distance between base and "pipe".
the box u have "tuned" is at around 18-20 hz. i didnt calculate it using a "propriety" software or anything, i used bass box pro. the bend and the distance from base has no effect on the tuning unless the port is too close to the base.
i think u or ur friend needs to fix ur software. it doesnt know the difference between 18hz and 38 hz. also u have not given the volume of the braces used. that too will have an effect on total internal volume of the box.
