Hello Caraudio.com guys I need some help trying to port an enclosure i have for a 8" type R. The dimensions of the box are 17"w x 18"h x 6: deep. the internal volume is .91 cubic feet if my math is correct. I would like it port the box and tune it around 36hz. i cant for the life of me figure out how to calculate the slot port to achieve 36hz. Id like the port to be around 6"-8" high and around 3"-4" wide but not sure how deep the port is suppose to be to achieve the tuning freq