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Bomtillington
05-14-2013, 09:56 PM
Hi guys I have a 6.2 cube box for two 12 inch l7 the port was going to be 3 inch wide and 13 inches tall but what do I do for length I don't trust the calculators so I'm asking you guys for help and is 3 inches wide enough or do I have to go wider any help is appreciated!

SounDrive
05-14-2013, 10:09 PM
Hi guys I have a 6.2 cube box for two 12 inch l7 the port was going to be 3 inch wide and 13 inches tall but what do I do for length I don't trust the calculators so I'm asking you guys for help and is 3 inches wide enough or do I have to go wider any help is appreciated!

What are the dimensions of the box? I can plug it in my box calculator for you

Also you'll want a lot more port area

Bomtillington
05-14-2013, 10:20 PM
I want it tuned to 33 hz and th box is 27L 34w 14.5 height

SounDrive
05-14-2013, 10:26 PM
EDIT: messed something up

SounDrive
05-14-2013, 10:29 PM
fixed it

http://puu.sh/2TH3d.png

5.5 wide port, 27 in long gives you 33hz with optimal port area with 4.8 cubes of net volume left

Bomtillington
05-14-2013, 10:29 PM
I can't do a port that long because the box is only 27 inches

SounDrive
05-14-2013, 10:32 PM
I can't do a port that long because the box is only 27 inches

You can bend the port in the shape of an L. Just make sure the port is always 5.5 inches wide at all points

Lowlacs
05-14-2013, 10:35 PM
Do an "L" port on one side of the box if u choose to do a common chamber. Or port out the side of the box if the L is too complicated. just my 0.02

Bomtillington
05-14-2013, 10:36 PM
Can I put both speakers on on side and the port on the other?

SounDrive
05-14-2013, 10:38 PM
Can I put both speakers on on side and the port on the other?

That would reduce your output significantly. You want your subs and port on the same face or faces right next to each other. For example: subs back port back; subs back port side; subs up port back; etc.

If you're talking about having your subs face back and the port fire out the side, yes that would work just fine. Just make sure there's enough room inside the box to mount your subs or you'll be forced to invert them

Bomtillington
05-14-2013, 10:45 PM
I was gonna have the subs facing twords the trunk and the port twords the trunk just both subs on the left and the port to the right instead of in the middle

Bomtillington
05-14-2013, 10:51 PM
Also is it okay to to have bracing in the port because it will be using the outside wall?

Bomtillington
05-14-2013, 10:52 PM
or if I wanted port length of 26 inches what would that tune it too this way I can center it and no have to make an l shape

SounDrive
05-14-2013, 11:13 PM
or if I wanted port length of 26 inches what would that tune it too this way I can center it and no have to make an l shape

26 inches wouldn't work because there would only be a 1 inch gap at the back. And yes, you can have the port against the side of the box (like you said on the right side with the subs on the left) and that will work just fine and be easier to build

About the longest you could go without bending the port would be 21 inches and that would give you 35Hz tuning

Bomtillington
05-14-2013, 11:17 PM
So if I went 21 I'd be tuned at 25 hz and still be at optimum port ratio?

SounDrive
05-14-2013, 11:21 PM
So if I went 21 I'd be tuned at 25 hz and still be at optimum port ratio?

Actually 20.75 would be the longest you could go, I forgot to account for the thickness of the MDF. But yes you'd be tuned at 35Hz with optimal port area and it would bump you up to 5.06 cubic feet.

Here's the final calculations with a cut sheet from my calculator if you'd like them
http://puu.sh/2TIAy.png