MikeMartel

Alright here, iv been looking stuff up and i dont understand whats going on here. IF i were to put my port through my rear deck, along with my two empty 6x9 holes and were to seal off the whole box from the trunk, shouldnt that have the exact same effect of sub foward port foward and sealing it from the trunk? Mine is just going to be sub up, port up. I really dont understand the problem. My rear deck is already fairly open, its not a solid piece of metal and wood so it should also be able to allow airflow from the subwoofer itself. If this still wouldnt work could someone please explain why sub forward port forward would work, but sub up port up wont?

Okay.. So last time I tried to design a box myself, a got the dimensions a bit wrong, there was a few things I wanted to make a bit different. Here are all the specifications Iv came up with and hopefully they are right this time. Box Net Volume 6.75 cubic feet Port Area 126 inches2 Port Tuning 30hz Port Internal Dimensions 9” x 14” x 46.63” Port Displacement (8.25” of the port will be external)(33.38” Internal Port) 9.75” x 15.5” x 14.25” (Part A of "L" Port) =1.24625651 cubic feet 9.75” x 15.5” x 18.38” (Part B of "L" Port) = 1.60745226 cubic feet 1.24625651 + 1.60745226 = 2.854 cubic feet + 0.18 cubic feet (Subwoofer Displacement) = 3.034 cubic feet (Total Displacement) Box Dimensions Needed (9.78 cubic feet) 36.75 x 15 x 37 = 9.776 cubic feet before displacement 9.776 – 3.034 = 6.742 cubic feet net So Im off by 0.008 cubic feet.. Dont think thats a problem though. Hopefully I have it right this time. And if it is right, Im done changing my mind about this box, i must have calculated about 6 different boxes for this setup and Im sticking with this one. Heres a picture of the design, roughly

Looks like im making a new design, xD

Yeah, back to the drawing board for me. Ill figure it out, ill just cut out a big slot in the rear deck, i saw a post that edouble posted yesterday talking about it. Ill try designing a new box with sub up port back and go from there.

Alright guys, Looks like ill be designing something new again, port through the rear deck isnt going to work according to basically everything iv read and that people have told me. No room for a bandpass enclosure and the BTL doesnt work so well in one anyways. Back to the drawing board.

Ok, so if I simply dont seal off the port then it shouldnt have cancellation? My rear deck isnt a solid piece of sheet metal to begin with, there are already some pieces cut out of it for more ventilation into the trunk space from factory, so this design isnt really much different than any other box design? Im only raising the port out of my box a couple inches. I understand the theory that cancellation would occur if the port and subwoofer are sealed in different compartments but they wont be. Also. Why would a 4th order ported through the rear deck work but my design wont?

Well you see that was the whole idea, lots of people say they gained SPL from cutting a hole in the rear deck lid, so i was thinking heck, i might as well just stick the port right there. . Hopefully it works well, if not, ill build a different box.

Well, This is what Iv decided to do, I'll try porting it through the rear deck and try it out for a week or two and maybe THEN I'll try sealing it off and see if it sounds any better or worse

Alright, thanks for being tuned in. Im excited for it aswell.

Main reason im doing this is because of my lack of folding seats. Porting it into the cabin simply should increase SPL and how well it sounds. If you do have experience with box building id like to know if what iv calculated is right.. Im still not 100% if i even designed it correctly.

At the moment no, Its much smaller. 5.5 cubes if im lucky, port is pointing sideways and it was a bit leaky. It was the first box iv ever built. But i think a box thats a bit bigger with more port area will be more optimal. Along with that, ill be porting my box through the rear deck and sealing it from the trunk so i can get some more air flow throughout my cabin.

Harsh. ^^

Beat the shit out of it. Always seems to work.

Yeah my mistake, was early in the morning and felt like posting something.. Still not sure about all the good drivers out there. Still learning. xD

I would not use the kickers or JBLS.

Holy wow.. That must have had some velocity.

Nevermind...

Alright, i made a rough sketch in google sketchup, not sized at all just random measurements but this is how i want it look, and the specifications i was thinking about using. The port is partly external because i will be firing it through the rear deck of my car. Tell me what you guys think! (Still working on perfecting google sketchup) Net volume ~ 8 cuft Port Area = 144in2 Port Dimensions = 9 x 16 x 37 (length) Tuning = 32hz Sub will be facing up aswell as the port.

Looks clean, I like the raised logos. Great work.

Never too much cone area

It seems with building one of your first enclosures stick with the recommended enclosures... SSA knows best of course, they built the subwoofers. ^^. BUT, if your being heard 5 blocks away, close your windows, turn it down a bit or invest in some sound deadner.

Ask them

Go with Fi soft parts, i put up a thread a few days ago asking about this and most people seem to think that his soft parts are shit.

Alrighty, So NEW Port and Subwoofer displacement is 2.493 cubic feet. Which means ill need my box with the dimensions of 36w x 38.6L x 15h = 9.999 cubic feet, which will bring me back to 7.5 cubic feet net, same tuning, and we are good to go. Correct? If im still wrong, somebody help me out here. I think iv got the basic idea down and i actually understand what im doing (hopefully). Thank you Stefan for your port tuning calulator, and thanks Alton for your calculator aswell, it gave me a great knowledge and understanding about how everything works and hopefully ill be designing my boxes all on my own soon enough.