MikeMartel Posted January 17, 2012 Report Share Posted January 17, 2012 Port Area 126 inches2 Port Tuning 32hz Port Internal Dimensions 9” x 14” x 40.00” Port Displacement (8.25” of the port will be external)(31.75” Internal Port) 9.75” x 15.5” x 14.25” =1.24625651 cubic feet 9.75” x 15.5” x 15.75” = 1.37748264 cubic feet 1.24625651 + 1.37748264 = 2.62 cubic feet + 0.18 cubic feet (Subwoofer Displacement) = 2.80 cubic feet (Total Displacement) Subwoofer Dimensions Needed (9.55 cubic feet) 36 x 15 x 37 = 9.568 cubic feet before displacement 9.568 – 2.80 = 6.768 cubic feet net Iv basically done all of the calculations myself but im not 100% sure if I did it properly. Just double checking that my math is correct before I go building this thing. Here is a picture for reference. Quote Link to comment Share on other sites More sharing options...
vibrator Posted January 17, 2012 Report Share Posted January 17, 2012 what sub are you using? Quote Henry Ford once received a letter from a depression-era bank robber responsible for the deaths of several law enforcement officers, killed in their attempt to stop him as he fled the crime scene. In his letter, he thanked Mr. Ford for making his Model A Ford such a good getaway car. Link to comment Share on other sites More sharing options...
412 CVX Posted January 17, 2012 Report Share Posted January 17, 2012 why wouldn't you just do a slot port Quote Just say no to Ground Pounder Customs. My temp system build log More box buildssome cars do over 170db with one sub, so clearly my two 12"s can do that in my car, with my knowledge too! look out bitches! I'm with captain stupid. Link to comment Share on other sites More sharing options...
MikeMartel Posted January 18, 2012 Author Report Share Posted January 18, 2012 Ok, im using a Fi BTL N2 18", the box design is basically just a slot port except part of my port is partly external. The reason i am doing this is because i am porting my box through the rear deck of my Impala. Im just posting to double check that my math is correct and everything is going to work out the way i have posted. Quote Link to comment Share on other sites More sharing options...
Joe X Posted January 18, 2012 Report Share Posted January 18, 2012 So where you will be installing the sub, also I imagine you will be placing a top lid.. right? Quote Link to comment Share on other sites More sharing options...
Joe X Posted January 18, 2012 Report Share Posted January 18, 2012 (edited) I will double check your calculations to see if something is off. Edited January 18, 2012 by Joe X Quote Link to comment Share on other sites More sharing options...
MikeMartel Posted January 18, 2012 Author Report Share Posted January 18, 2012 Yes, sorry for not explaining myself perfectly, but yes there will be a top lid, and that is where the subwoofer will be mounted. the reason i left it out is for easier visualization of my port. Quote Link to comment Share on other sites More sharing options...
Joe X Posted January 18, 2012 Report Share Posted January 18, 2012 Ok I just need have clear a few things: 1) The mounting depth of the sub is 11.125" so not sure if it fits with the port below. 2) Not sure (I guess) the box dimensions you are giving are internal?? 3) if the port is using the bottom of the box as a lower wall as the sketchup seems to suggest, your port displacement is miscalculated and the port tuning is also off because end correction for slot ports applies. 4) Also the length of the port should be calculated on the centerline of the port not sure if you did it that way. To note, I have not made any calculations, these are just a few things I am not clear about. Quote Link to comment Share on other sites More sharing options...
MikeMartel Posted January 18, 2012 Author Report Share Posted January 18, 2012 (edited) Ok.. Well, 1. Im going to have my sub mounted in a way where it is out of the port. 2. The box dimensions are external dimensions. 3. I am using the bottom of the box as part of the port, but i thought i took that into consideration when i was calculating the port displacement. Instead of adding 1.5" to the port width to find the external dimensions of the port, I only added 0.75" since there is only really one side being added to the inside of the box. (Im not sure extactly what end correction means.) 4. Also not 100% sure what you mean by measuring it from the centerline. (Im thinking iv messed up now ;P) Edited January 18, 2012 by MikeMartel Quote Link to comment Share on other sites More sharing options...
Joe X Posted January 18, 2012 Report Share Posted January 18, 2012 (edited) Ok so there is a box wood displacement to consider here, from your external dims you need to substract 1.5 inches to each dimension, that will be your gross internal volume, the port and sub displacements are deducted from there. Also to read this to know that I was talking about in my previous post: http://www.jlaudio.com/header/Support/Tutorials/Enclosure+Ports/Tutorial%3A+Enclosure+Ports/656168 Hope this clears everything out. Edited January 18, 2012 by Joe X Quote Link to comment Share on other sites More sharing options...
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