Tuning for 2.2cuf, Diamond Audio d3

[fox_forma 10+ year member]

I am about to finish building the box for under the ex cab bench seat in my Silvy. After all measurement the box is sitting at 2.2cuft of space. The D3 says it needs to 2cuft ported so I figured this is a good number. Doing the calculations to tune it to 36hz I need a 4" port about 9" long. Is this the best way to go or should I tune to something else? Should I stick to one port to use two?

Also last, the sub will be on the passenger side facing the seat and from another build thread I saw the person put the ports facing the ext cab door out the side. Is this optimal or should I consider doing ports out the front of the box facing the back of the seats?

Thanks

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[fox_forma 10+ year member]

anyone? I don't see a way to be able to get two ports in this thing and a single 4" just doesn't seem like enough. What options is there to get the proper port area needed? I have about 18" of length to work with if I face the port towards the ext cab door and about 7" to work with in height.

 

[LilJ29 10+ year member]

Do you have a silverado SS? I think i just read a post from you on the silverado ss forums haha..I don't see anything wrong with using that one port. If you need more length you can bend the port too. I havn't seen any port noise coming from a 4inch wide port, with only 1 12. Everything should be cool man.

Did you make that box custom yourself? it would be amazing if i could get 2.2 cubic feet under my bench too, im using barely .7 and .7 for each 12 i have //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[fox_forma 10+ year member]

Yeah i'm on SSS.com. I was running the subthump box but its just collecting dust now. 2.2cuft is about the most I could squeeze out without making the box look like its not meant to be there. I may slot port it as well after looking at it but I built another box last night just to get me by which is 1.6cuft just for the one sub. I have to wait to put the port in and now I have to buy another sheet of MDF.

For reference if you decide you want the extra airspace the box is 55in long, 15in deep, 10in front, 8in in the back and I just built it up as close and tight to the center hump under the seat as possible.

 

[RAM_Designs 5,000+ posts]

Do the port firing to the side. Your box gives you 3.13ft^3 of space before sub and port displacement so you have some room to make up in order to get down to 2.2ft^3 for the sub.

 

[fox_forma 10+ year member]

Sorry, my box would give me those specs if it were all squared off but since it goes under the rear seat of my silverado ex cab there is a hump in the middle that I had to account for. On each side of the hump I am getting .85cuft and over the hump its only .52cuft so if I am doing the math right it comes out two .85x2 + .52 for overall space.

 

[LilJ29 10+ year member]

would you be able to take a picture of your setup for me please man? would be really appreciated

 

[SpeedEuphoria 10+ year member]

most say you need 6-10 square inches of port for aero/round ports, 6-8" for true aero's and 8-10" for PVC. Both of these are PER CUBE after sub displacement and any displacement the port takes up inside the box.

The formula is, for a 4" round port, 2^2 x Pi. So a single 4" port is ~12.56"^2.

If you did a true aero(bell shaped flares) this should be fine. Otherwise you prob want a 5" port.

Just realize that the wider the port the longer you will need to make it for the same tune

 

[fox_forma 10+ year member]

When using an online calculator for the port I realized that, going up in size is where i would run into issues because I only have about 18" on the port side because of the hump in the middle under the seat. I could prob get away with two 4" ports if need be as well. Is there a big difference in using 4" PVC and flaring at the end compared to buying actual aero ports?