Ok.. after a lot of contemplating and measuring I've come up with this for external measurements..
17x39x16.5 5.046cu.ft (before displacement)
No more pulling boxes in and out of my car so I'm going to make interchanable ports.. for starts I'm thinking 28,35,and 40.
28hz - 10x4x35 35hz - 10x4x16.5 40hz - 10x6x20.5
Now the questions begin..
If I made the 28hz port 10x3x21.5 have a port noise problem? Normally long ports with a small width yield noise but cutting an inch in width ill dramatically reduce the length.
The 40hz port is going to be for SPL comps. Would the width of the port yield better results over a port tuned to the same frequency with a smaller width?
I'm open for new port dimensions.. i.e height, width, whatever it takes. Just looking on some advice. Don't want to create something with bad port noise. The port edges will be rounded off to reduce it as much as I can but a poorly designed port would not help me with my cause .. I know a bit about box building but this is my first attempt at interchanable ports and I don't feel like messing something up
Just buy a bunch of 4" PNR ports and cut the different lengths, duct tape the ports together and switch middle pieces when you want to change. Much easier to trim and tune with than slots, and less port noise.
dude, 3 inches is enough, i usually do like 6 inches just cuz it looks sick and does nice hair stands, but 3 inches shouldnt have too much port velocity, and 4 the 40hz idk it might not have enough velocity because theres not enough sq inches, how many square inches is it? i dont feel like calculating that, my brain hurts
its roughly 20 square inches of port per cu.ft of box.. i know its more than recommended but my current box has quite a bit of port area and it puts up 145s @ 42hz
oh dang sorry, i didnt notice the 6 inch wide port i thought they were just shorter, yeah they all look good to me, port area and stuff at least, i wouldnt worry about it
thanks marshall ... i was worried about the port noise.. im running a 35hz port now and it seems fine so if the 28hz one has bad port noise its not that big of a deal cuz i can switch out to the 35hz soon enough lol..
so you think i'll be fine with 10x3.5x25 .. minimum port noise? think 4cu.ft will be too big considering the sub will be powered by that 35.1? im willing to reduce the box size if need be.. of course i still have bracing to add and such so ill just have to factor everything in. i was thinking about going to 3.5cu.ft .. which do you think will yield better results
.. I know a bit about box building but this is my first attempt at interchanable ports and I don't feel like messing something up