Need help with ported wall
 

I am building a ported box/wall for 6 HFX12D4 12” subwoofers. The box measurements are 40” length x 18” width” x 34” height. There will be two 5” ports which are 3.6” long. The tuning frequency is for 32 Hertz. The box enclosure volume is 14.167 cubic feet. I was wondering, would these measurements be efficient enough for the subwoofers? If not, do the ports need to be shorter/longer? Or, should the box measurements be smaller? Box enclosure volume? I do not want the box to be too big/small. The subwoofers will be powered by two Planet Audio AC4000.1D Amplifiers strapped together. The wall will be going in a 1995 2 door Toyota Tercel (back seat removed). The measurements (listed above) are the maximum measurements the Tercel can fit due to limited space. I used the port length calculator to obtain the measurements of the port size.

If you build from 3/4" MDF, the max volume before taking away woofer and port displacement is only 12 cubic feet. You will need to have a double baffle at absolute minimum, and plenty of bracing. The extra baffle will cost you 0.6 cubes, and some 2x4s and steel rods perhaps will cost you another 0.4 cubes lets say. You're down to 11 cubes. Now each speaker will displace probably around .12 cubes. So thats 0.72 cubes lost. Now you have 10.28 cubes before port displacement

Now the rule with ports usually is - 12 to 16" of port area per cubic foot. But with round ports IF they are rounded/flared (look up flared or aero port on google) you can get away with 9 cubes per foot, especially with lower powered drivers like yours.

To achieve that you'll need around 90 sq inches for your 10.28 cubes (the volume goes down anyway once you account for port displacement). So three 6" ports will give you just under 90 sq inches which is great. - Three 12.5" long 6" diameter ports will give you a tuning of about 35hz. You will lose about .19 cubes each, leaving you with around 9.7 cubes net volume That's 1.6 cubes net per speaker, which is just within their specifications.

Thank you. I do not think I have the room for three 6" port holes. Could you come up with a design an send it to my e-mail at whitleyad2@vcu.edu. The maximum measurements are 34 high 40 wide and 18 deep. Thank you again for your help.

shoot a msg to It Hrz , he has alot of experence with walls

ok thank you

Thanks Luke, First off with a wall build you need to have a slot port, this will give you extra strength for the enclosure and you will obtain much better BASS. Now with this being said what is your goal here? Is this going to be for competition? or just a daily driver with lots of boom ?

Just a daily driver. How long and how deep does the slot port need to be with the dimensions I gave earlier?

I need to have some clarification here on your dimensions. This what I need to know, lets just say that you have no front seats in the vehicle and your sitting in that space and looking into where your enclosure is going to be.
So looking into the back, your WIDTH is from side to side, your HEIGHT is from top to bottom and your DEPTH is from front to back. So that would tell me this: width= 40"
height= 34" depth= 18" CORRECT?

I need to know something else as well, grab a tape measure and measure your woofer I need to know what the EXACT outside diameter is.

Correct. Those are my dimensions of the box looking from the front seat to the back. The exact outside diameter of my woofer is 10.94".