Enclosure for 2 OA 18's Design Help - sealed or Sub/port up (space issues)

[Derp]

After looking around and finding lots of great information I would like to ask a question. I have 2 18 inch OA v1s (gottem for next to nothing!) which I would like to make a box for. My max dimensions are H17 x W39 x L36. which would be about 10.8 Cu. Ft. I'm having a little trouble figuring out the slot port dimensions to be in the 28-30 Hz range for ported. Even with the slot port the box would be at least 10 Cu. Ft. (I hope!) which is acceptable according to the OA website the ported volume should be about 4.5 to 6 Cu. Ft. each. I'm currently using Torres Box Calculator. I'm also wanting Sub up/Port up so I can build it as big as I can and that's where I get confused. According to the OA site one 18 needs from 28.3 in^2 to 50.24^2 of port area. If I stay between those two numbers I should be fine? I would double the area of course since there are two subs (56.6 to 100.48). Is there enough room to port them properly? Or should I just seal it? I will only be putting recommended wattage to them ...600 if that matters any. Any help will be greatly appreciated.

Here are the specs if anyone is interested in lending a hand.

Obsidian 18" v2 D2
Re: 3.97 Ohm
Fs: 25 Hz
Qms: 4.48
Qes: 0.840
Qts: 0.707
Vas: 156
Le: 3.72 mH
BL: 19.12
SPL: 86.88 dB
Sd: 1217.34 cm^2
Mms: 479 g
Xmax: 20mm
Peak-to-peak: 62mm (2.45")
Power Handling: 600 watts RMS

Recommended enclosure info:
Sealed ~ 3.5 to 5 ft^3
Ported ~ 4.5 to 6 ft^3 @ 28 to 32 Hz
Cutout: 16.7"
OD: 18.5"
Mounting depth: 9.5"
Mounting flange to top of surround: 1.5"
Displacement: 0.25 ft^3

EDIT: I believe I'm going sealed...The previous owner had them in a ported box ...I believe 11 cubes with a cheaper Planet Audio amp and they sounded Amazing! There is no way I'm getting it 11 cubes and ported ....hell I was messing around with the Torres box calc. and can barely get 9 cu ft with port displacement...so sealed it is for now unless someone has any other options? I would love to try ported first...never had a ported sub..... help a mofo out!!!!

EDIT EDIT: Been doing more measuring and it looks like I will be able to build a ported box at about 11- 12 cu. ft. Not sure on the exact dimensions of the box but it will be bigger on top. Not a slanted box but ...sort of a box in top of a box if that made any sense....anyways buying mdf tomorrow. Still trying to figure out the Port

Thanks!

[Derp]

Well...Box turned out to be 11.226 after all displacements. I have about 5 3/4 - 6 inches from the back of the box to the hatch. I have a little over 16 inches from the box to the roof. I was wondering if that was enough room to have ports facing back? I was going to run it sealed but I KNOW once I seal it up I won't do anything else to it. I was also wondering what size port I should use...6 inch ? 8 inch ? two....

Thanks!!!

[john253a]

4off

6" psp aero ports at 17" (35-37hz)

Or 20" if you want a lower tune

[Derp]

I used PVC pipe ...but box turned out good. We'll see how it sounds. Tuned to 29 Hz....checked several "calculators" and they were all about the same, maybe a 1\2 inch off for port length. OA specs say that each sub needs to be paired with a six or eight inch port .....I'm trying six now. I had extra MDF and made another side (where ports go) so I can try eights if I dont like how it sounds. Pics and video up soon...day or two

Small batteries I "stole" from a guy because he was hard up for cash

Still have to clean it up but I am rather pleased with it.