Joe X

Yes it needs to be calculated.

Ok, since you have no particular dimensions here is a design suggestion that seem to fit nicely in most cases: Enclosure Specifications: Fb = 35.057 Hz Vb = 3.189 ft^3 Subwoofer Mounting = Flush Mounted External Height = 16 in External Width = 40 in External Depth = 16 in Port Width = 3 1/2 in Cut List: * All Dimensions in Inches. * Wood Thickness is 3/4 for all Parts. External Enclosure Parts: Front = 35 3/4 x 14 1/2 Front Internal = 34 1/4 x 14 1/2 Back = 40 x 14 1/2 Left & Right Sides: Side 1 = 14 1/2 x 14 1/2 Side 2 = 15 1/4 x 14 1/2 Top & Bottom = 40 x 16 L Port Internal Assembly Parts: Front to Back = 11 x 14 1/2 Extension = 11 1/4 x 14 1/2 Here is an assembly giude: Let me know any questions.

What are your maximum dims and how much power do you have available.

What about Vd Vd = Sd x Xmax

So you are not saying what bracing you were considering to do so it's not drawn: I was wondering also you just put that little port on the side and got asymmetrical load?? Or where did you place the little port.

Ok, on your dimensions I came up with this 3cuft@34Hz slot ported design: Enclosure Specifications: Fb = 34.074 Hz Vb = 3.041 ft^3 Subwoofer Mounting = Front Mounted External Height = 17 in External Width = 30 in External Depth = 17 in Port Width = 2 3/4 in Cut List: * All Dimensions in Inches. * Wood Thickness is 3/4 for all Parts. External Enclosure Parts: Front = 26 1/2 x 15 1/2 Back = 30 x 15 1/2 Left & Right Sides: Side 1 = 15 1/2 x 15 1/2 Side 2 = 16 1/4 x 15 1/2 Top & Bottom = 30 x 17 L Port Internal Assembly Parts: Front to Back = 12 3/4 x 15 1/2 Extension = 8 3/4 x 15 1/2 It assembles like this: The main issue with the calculations you had was the port area, and therefore the port volume.

The specs say 1-2 cubic feet of gross volume so you are on spec on the tight side, it would be best if you posted your max external dims to get a better idea of what can be done.

To do the shared port design I would need an extra inch deep thats all.

Ported makes your bass deeper, if it was for the 3 dB gain only I'd say maybe is not worth it.

A shared port design will require some more space than 15x30x15.

What subs are going in??

You will get louder and deeper bass with a ported enclosure. The center divider becomes necessary if you are using one amplifier per sub, when the output of the amplifiers is not exactly the same power will be lost without the center divider. If you want a sealed enclosure with a center divider anyways they are sold prefabricated just make sure are 1.25 cubic feet per chamber.

Hope you mean Pioneer TS-W303R Here is the suggestion: Enclosure Specifications: Fb = 36.033 Hz Vb = 2.454 ft^3 Subwoofer Mounting = Front Mounted External Height = 15 in External Width = 30 in External Depth = 15 in Port Width = 2 1/4 in Cut List: * All Dimensions in Inches. * Wood Thickness is 3/4 for all Parts. External Enclosure Parts: Front = 27 x 13 1/2 Back = 30 x 13 1/2 Left & Right Sides: Side 1 = 14 1/4 x 13 1/2 Side 2 = 13 1/2 x 13 1/2 Top & Bottom = 30 x 15 L Port Internal Assembly Parts: Front to Back = 11 1/4 x 13 1/2 Extension = 5 x 13 1/2 Here is an assembly guide:

The port does bend so you need to know how to get the physical length of the port, also bracing (specially for the port) and a double baffle seem in order, may be possibe to come up with something more functional, what subs are going in??

Those are specified at 1.25 cubic feet per sub so 2.5 cubic feet net internal volume is what you require. Aero ports would be the easy way to reach the rear deck.

Post your maximum dims and I will submit a design suggestion.

The sub displacement is .071 according to http://support.alpin...M_SWR-1242D.PDF I was looking at the current Type R 1243.. just make sure you have the old one.

You changed the driver displacement to a wrong value it should be 0.2 cubic feet as before.

Just a few notes, the shared port is twice as thick on the center duct than in it is on the lateral ducts, you don't need the double baffle on this design but if you want to do it then add 0.75 to the depth so you don't go low on internal volume, you need 1.5 cubic feet per sub of net internal airspace (you are low). The T parts you added to the port reduce port area, I believe are not necessary. you need to set common walls to 2, set baffle thickness to 0.75 if you are adding the extra layer.

You can also look at obsidian, sundown on the price range.

Optimal is 0 degrees of phase or no delay between drivers, there will be some loss by firing at 90 deg of each other. anyhow firing upwards inside a vehicle with trunk is just a no go regarless of cancellation.

To answer your question, I don't see how placing some of the subs upwards can help, but there are other things to check,for example assuming a 36Hz tuning you would have each sub with 0.73 cubic feet of airspace each their range is 0.6-1 cubic feet so you would be on the tight side, you need to be running them with at least true 1600W RMS (400W each) to get what they give. You can safely run them to 500W each. Also you need 1880W or clean 134 A to properly run them on rated power, yor gains, your tuning, have an effect also....

The SSD15 is 1000W RMS and a better sub for the price.

You say you have subs and port on the same face and most of the times that's best, the better way to give feedback is listing the specs of your box and your equipment, and the vehicle you are using.

Yes you can it's just PVC pipe: http://www.lowes.com...ld|1&facetInfo= To get better results just sand the ends of the pipe so that there are no sharp edges and you are done. If you are into spending a lot you can buy flared ports: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=268-352