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View Full Version : First Time Building ported box for SA-12 Help confirm please



USAFMileHigh
06-12-2012, 07:28 PM
Vehicle - Cobalt SS (4 door sedan)
4 Guage wiring already run from previous system (2 Sealed Infinity 120.9w's + Infinity K One Mono Amp)
Yes there is a 1 farad capacitor in there -_- it was a while ago don't hate...
I am fairly savvy, I understand impedence and how to run the wiring, but I'm not a car audio guru so keep the jargon to an intermediate level please :D

I am purchasing:
Hifonics Brutus BRZ1700.1D
Sundown SA-12 D2

HOWEVER, in the future (probably a month or two from initial purchase) I will be getting another Sundown SA-12 D2 and run them at 2ohms. Therefore I need room for a second box...

ON TO THE BOX:
I was going to build a dual ported box initially and purchase 2 subwoofers, but I've decided to step up from Type R's to SA-12s due to everyone on the internet everywhere celebrating them, as well as myself checking them out on other audio sites and youtube. Now my goal is 1 ported subwoofer box, that leaves enough room for another subwoofer box to slide next to it if I choose to add another.


Sundown Audio recommends a ported box with the size: 1.5-2.0 ft^3 @ 35hz
I have been playing around with the RE AUDIO Box Calculator (google it, won't let me link) and believe I may have found a box that works, I am just looking for some confirmation. These are the specs it gives me:
Box Width: 16
Box Height: 14.5
Box Top Depth: 20
Box Bottom Depth: 22
Wood Thickness: .75 (MDF)
Square port Width: 2
Square port length 1: 18.25
Square port length 2: 8
Total Port Lenth: 30
Box Volume (ft3): 1.811
Tuned Frequency (Fb): 33.6 (I figure adding the sub will make it ~35)


Height is really an issue in this vehicle due to the openings to the trunk from the outside as well as the cab, I might be able to squeeze another inch out of it in height if I temporarily remove the back seats which can be a pain... The total usable width is ~36in and length I don't really want to go over 24 but that would be fine. Keeping in mind, I will in the future be buying another SA-12 and building the EXACT same box so it fits. I guess the real question is will this box sound any good? Can anyone recommend any tweaks or changes that would improve it? General box building tips? This will be the first box I've ever built. Also, creeped the forums alot but this is my first post :D so excuse the etiquette, if you need anymore box/subwoofer/vehicle information from me feel free to ask! Thanks!

USAFMileHigh
06-12-2012, 07:30 PM
Thread has been Edited to include extra box information :D

jolly_26
06-12-2012, 07:30 PM
lose the cap?

USAFMileHigh
06-12-2012, 07:34 PM
lose the cap?

...why? It actually seemed to reduce headlight dimming from my old system when it was added.

jolly_26
06-12-2012, 07:42 PM
...why?

Sell it and buy something useful. More often than not they will just add extra stress on the electrical system. Also just refreshed and noticed that my computer wasn't showing the whole post, only had the first 4 lines showing. Wasn't sure what you were asking so just threw a bit of advice out there. Regardless, I still think you should lose the cap.

On the box, sounds good to me! Maybe a slightly lower tuning if you really like hitting the lows but that's all preference so idk. Also what do you mean by length 1 and 2 of the port?

USAFMileHigh
06-12-2012, 07:47 PM
Sell it and buy something useful. More often than not they will just add extra stress on the electrical system. Also just refreshed and noticed that my computer wasn't showing the whole post, only had the first 4 lines showing. Wasn't sure what you were asking so just threw a bit of advice out there. Regardless, I still think you should lose the cap.

On the box, sounds good to me! Maybe a slightly lower tuning if you really like hitting the lows but that's all preference so idk. Also what do you mean by length 1 and 2 of the port?
Yeah I had made a second post saying I was editing it :P The forum wasn't liking something so I put it all into Microsoft Word and put it back in bit by bit haha. It is going to be an L port so Length 1 is refering to the length attached to the opening. This is the link to the Re Audio Box Calculator (http://reaudio.com/box.php) that I used

jolly_26
06-12-2012, 08:34 PM
run your measurements through winISD or the 12volt box calculator and if you get all the same answers go hard at it, sounds good. I've run 12's in boxes from 1.3cu.ft to 1.8 cu.ft, and the next one will be a 2.2cu.ft. But that's getting 1500rms haha. I'm no expert but at about 34-35Hz 1.8 will be about right for that sub.

dbeez
06-12-2012, 08:57 PM
If buying a second Sa look at getting dual 4's cause getting 2 and running them at 2 ohm is just a waste of money and time plan it for full power on the par not full power on one sub then half power split on 2 subs.