Joe X

You need know the net volume of each chamber and the length, the port cross-sectional area, and the t/s parameters of the sub to determine it's behaviour..BUT modelling software assumes constant cross-sectional area ports to determine tuning of each chamber and it's not the case with this design.. so you should ask the designer in any case, generally 6th order enclosure sound very loud but quality is bad, usually lots of group delay around the tuning frequencies. I wouldn't build something like that unless I knew for a fact that it will work.

it's a dual reflex bandpass (6th order).

Why woild you want to build that, also hope it was designed speciffically for those subs.

Look for a CEA certified amp, usually stock electrical will tolerate 1KW sub system, better with a 80-90A alt, you may want to check your electrical to be in good condition though.

Ok now you have the space but need to know what vehicle is this and probably a pic of the interior and some infos on how do you intend to install this.

2 15" on 40"x15"x12" that's about 3 cubic feet before displacements..

Re is the DC resistance of the sub not the impedance, any sub measured with a multimeter will show a lower value than the impedance rating.

Do you have a link to a pic of your car interior?

Here is a suggestion port/subs to the front, here is a link to your sub specs: http://www.skaraudio...cts/vvx-15.html Assuming a final load of 1 ohm the 2500W RMS is high, set your subsonic filter to 25-27Hz. Enclosure Specifications: Fb = 30.011 Hz Vb = 5 ft^3 External Height = 18 in External Width = 48.5 in External Depth = 18 in Port Width = 4 1/4 in Cut Sheet List: * All Dimensions in Inches. * Wood Thickness is 3/4 for all Parts. External Enclosure Parts: 2x Front = 21 3/4 x 16 1/2 2x Front Internal = 20 1/4 x 16 1/2 Back = 48 1/2 x 16 1/2 Left & Right Sides: 16 1/2 x 16 1/2 Top & Bottom = 48 1/2 x 18 Shared Port Internal Assembly Parts: 2 x Front to Back = 14 3/8 x 16 1/2 2 x Extension = 13 15/16 x 16 1/2 Let me know any questions.

You are doing port up/sub up, it's recommended to do port/sub front or back, you can since your box can be 18" tall.

And your tuning is 37.14Hz, for a port/sub front or back you are good now, you can go up to 4.5 cubes net if you wanted.

I had changed my width to 30.. forgot to post it that's my fault, but it's not the length that I'm worried about.. the port isn't the same height as the sides, and front and back.. Check the Torres cut sheet list, parts are also 12 1/2 tall, 14H - 1.5 = 12.5, This is why I usually submit a full spec of a box..

20 1/4 + 10 3/4 = 31 but need to be installed as intended.

I have never checked that before but it's ok, that is if you don't mind cutting a 11+ in. sub cutout in a 12.5" tall panel.. to avoid issues when the box is not tall enough for an easy panel cut I go for all across baffles.. it's just a question of preference.

That's alright, the port parts length would be: L Port Internal Assembly Parts: Front to Back = 9 x 12 1/2 Extension = 18 1/2 x 12 1/2

Your port height needs to be 12

Do it in the blazer, subs up port back 10.6 cubes gross (before displacements) @ 32-33Hz, If the amps are not strappable maybe separate chambers, 2 subs each. If you can give maximum dims I could get more specific. Edit: you could also run all 4 subs from a single amp colils in series subs in parallel. Of course non cea certified hifonics will deliver below rated power.

It really depends on the subs the 18" nightshades need 4 cubes each.

What are your maximum dims?

Ok,The vehicle and amp(s) models. the max dims for the box and type of music you listen to.

Port and sub in opposite faces of the box is a no go.

The port part lengths match the ones I gave you, I don't know why your sketchup makes it look to me like the port is wider after it turns, I did my own to check that is not the case. If you want to place the sub in the center that's ok.

Ok here is a pic from another box the port length as in the Length box is 24" and the port was 5.5 wide: Hope it helps.

Hows this lookin The port height to width ratio must be kept 9:1

Sure.