APX18Q1.4 super duper box... Hof', need your help!
 

Hokay... Ready to start designing a box for the new sub...

Only box calculator I've found so far is at http://www.subwoofertools.com/forum/ported-box.asp

The absolute maximum outside dimensions of this box cannot exceed 40 in. long x 22 in. height x 20 in. wide.

Which makes it just over 10 cu ft, OSM.

So, I played around a bit and made a second shape that adds an extra 1.5 cu ft, for a total of 11.5 OSM.

Oh now that I think about it, I could make that 22 height any height I want... up to say, 36 inches. Because I'm thinkin' for daily, the box will lie on it's side, sub facing rear doors. And for comps, I'll flip it on it's back so the sub is facing straight up. Window line is at 23 inches, so that's why I got 22 there. But the depth of 20 is more than safe, so ya... I could make this a lot bigger...

So nix that 22... let's make it............ 28... If I just make the square box... that's just under 13 cu ft, OSM.

Soooo....... I want this box just like my competition box for my 12" H2. Sub and dual ports facing up, so I can plug one for daily SQ.

I can build it, but I can't design it... I'm lousy at math... Hopefully someone here can design it for me, right down to board cut sizes... Pretty please with sugar on top?

So, 40 L x 20 H x 28 W = 12.962962962962963 cu. ft. OSM. Both ports open, I'd like tuning at 50 or higher. 60 even. Plug one port, I'd like tuning 32-36 or so.

Here's a pic of my existing box that's about 3.5 cu ft, dual ported just like I want to do the new one...

http://firebase.com/grizzz/tuneweb/images/PICT0001.jpg
(You can see more pics at http://firebase.com/grizzz/tuneweb/ )

Here's a rough sketch I just did of the new box:

http://www.allstart.net/18box.jpg

I'll use 1 inch thick mdf, most likely. But it might just be 3/4. Should I get bracing in there too? It'll all get glued & screwed together, except the baffle board. It will be removable, sealed off with 5/32" weatherstripping (good thing I got that bigass roll when I built my last box eh?) so that needs to be take into consideration. And if the box performs well (which I assume it will) I'll get it sprayed with Line-X bedliner again. So that will add another 2 or 3 mm to everything... OH I'll want 45 degree angle boards in there too... If you lay the box on it's back, sub facing up, in the bottom of the ports I'll put in 45 degree angle boards, as well as the opposite end of the box. I did this to my existing box, and it gave me about another 1.5 dB :)

Here's some specs on my sub, I dunno what the depth one is (how deep the sub is), or how much space the sub itself uses up... But maybe it's in here, I dunno what all these specs mean...

Can't get this to post nice, but the info's there... Two different subs, so two different specs. And my exact sub isn't there, an APX18Q1.4, we gotta guess...

APX18Q2 APX18Q.5
Revc (ohms ) 2 2
Fo (Hz) 28.85 32.25
Sd (sqM) 0.1195 0.089
Bl (TM) 41.3 26.38
SPLo (dB) 94.9 95.67
Xmax (mm) 15 15
Dvc (mm) 75 75

Qms (m.q.) 5.72 5.39
Qes (e.q.) 0.26 0.2
Qts (totQ) 0.248 0.19
Vas (liter) 195 144
Cms (uM-N) 96 71
Mms (gram) 271 321

Oh, here's a couple "recommended" boxes by the manufacturer. They're designed for 5000 watts.

APX18-ported 6.0ft3 (40six10"long) ( 32Hz)=5000w (SB)
6.0ft3 ( 120six 1"long) ( 65Hz)=5000w (SPL)
Bandpass Rear Chamber:3.0ft3 sealed
Front Chamber: 6.0ft3 ( 100si x 8" long) (72Hz)
Bandwidth: 50-78Hz=5000W (SPL)

Oh, opinion's, other ideas, and sketches, are more than welcome.

This box must fit in my van, a work van / beach blaster / mobile theatre / SPL vehicle. With this box in it's daily position (on it's side, facing rear, pushed up against seat, port plug in place), I'll still be able to load 1000 pounds of batteries / parts on workdays. Or open the rear doors and light up the beach for the weekend. Or flip it on it's back, move to rear doors, pull port plug, and BOOM.

You get the idea ;)

I thought about putting up a wall on my "C" pillars (just in front of rear wheels, where sliding door meets up, right behind the middle seat, I have no rear seat) and simply free-airing the sub, way up high. It would work, and look ultra-cool, but I don't think it work well. And it'd move me up a class in dBDrag's, due to the wall, and I'd never be able to come close to the walled guys if it's way back on the C instead of the B pillars.

if you want i can draw something up for you tomorrow if i have the time,im assuming you are aiming for a really loud daily driver, but if you go with a design similar to your last box you can plug one port for daily drving ( having it tuned to something like 33hz) and then if you can more spl remove the port plug and the tuning will raise equaling more spl:cheeky4:. hit me up on msn.

edit i should have read your post a bit better about the port plugs lol.

Oh absolutely no hurry whatsoever... I don't have the wood yet, nor can I afford it, as I'm saving for gas/entry fees for the Kelowna show next weekend. It's gonna be a month before I get to build this box I think...

But don't worry, I'll bring the APX to show off at the show. Maybe we'll hook it up to the amps just sitting on the floor in the back for a thrill... ;) You makin' the trek to Kelowna?

Oh that reminds me. I use two Orion 1200d's for my sub right now. So for it's break-in period, I'll try it hooked up to the bridged amps at 1.4 (series two coils together to get 2.8, then parallel the two sets together to get 1.4 final). That should give it roughly 2000 watts. Then a few days later I'll hook 'em up at .7 final (unbridge the amps and give each amp two coils parallel), which should be good for 2700 or so... 3000 with my locomotive battery setup for competition. And then I'll decide which I like better for daily driving, 1.4, or .7. Most likely the former, as my 140 amp alternator works it's ass off at 1 ohm as it is... ;)

But eventually, I hope to double up on power (either with 2 more 1200d's or trade'm in for bigger stuff). So the box should be designed for up to 6000 watts I guess. And SQL with the plug in is far more important to me than SPL with the plug out. It'll be loud, no matter how ya cut it. Makin' it sound good while slamming at the same time, is what I love about my 12" H2. I hope to get this APX to be about the same...

And yes, I want it to WANG, and still sound as good as it can, being an SPL oriented driver in the first place. My comp box for my H2 is way louder than my daily box, even with it's port plug in. I'm still not happy with my daily H2 box and need to shave another 1/4 inch off each aeroport. But I love that comp box... ~33hz with the plug in, and just loud enough to rattle your vision. 50hz with plug removed and running a 50hz tone, 146.6dB on the windshield is my best score.

And I have no idea what the resonant freq. of my van is...