View Full Version : Ported box help for a 8" Alpine type R

07-27-2013, 07:25 PM
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

07-29-2013, 03:37 PM
How thick is the wood? If its external dimensions are 17 x 18 x 6, and its .75" thick wood, you have around .66 cubes before displacement. Too small to be ported IMO because the port will eat up a lot of room, unless you use an external port. If you use .5" wood (make sure to brace it), you'd have around .78 cubes. At best, with .78 before displacements, you could try to use a 15" long 3" round port to get it tuned to 40hz. Your goal of 36hz is just too low for a box this small.

I think you're better off sealed. Or a bigger box.

07-30-2013, 02:38 AM
Opps I have the wrong specs it's 17x19x6 sorry. The box is made our of fiberglass. It's about .25" thick give or take. I know alpine states they recommend porting at .70 but so I figured I'd have a little bit more room to work with. I was hoping I could pull something off.

08-04-2013, 07:51 PM
Any help please lol