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how to design a sub box?


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#1 HIPPO

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Posted 06 August 2012 - 05:31 PM

hi all,

starting to think about the sub box for my sub. i have decided on doing a box instead of a fibreglass spare wheel well design. Mainly so i can take it out if i need to.

so here are the details of the sub


33KX Technical Specifications
13″ (33cm) Subwoofer
High power handling
Use in sealed box from 30 to 50 litres (1.059 – 1.766Ft3)
Max. Power: 800 Watts
Nom. Power: 400 Watts
Sensitivity (2.83V/1m): 90dB
Long throw butyl surround
Frequency Response: 30Hz* – 1000Hz
Double voice-coil: 2-9/16″ (65mm)
Impedance: 2×2Ω

http://66.147.244.24...12/06/33_kx.pdf

there is a ton of info in that link. it will be powered by a 500w amp. i am thinking that a 50L box would suit me best unless anyone can suggest other wise. Would i need bracing? i have looked at a heap of box build threads and have a pretty good idea on how to build it. its just the actual size of the darn thing thats stumped me. i am tipping that a sealed design is what i am looking for aswell.

i will post up pics on what size i have to work with tomorrow if that will help anyone.

as a side note is there a online site that i can input details and it will do the maths for me??

thanks in advance

graham

#2 Equilibrium1990

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    Mr. Buy 1st think l8r

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Posted 06 August 2012 - 07:54 PM

First things first, You need to work out what you want out of your sub.

As you have noted the awesome team at Focal has a mammoth amount of info in their PDF's just to make this very simple for us noobs :-)

They have denoted the following:
30 liters (1.06 cu. ft.) F - 3 = 42Hz / Fast and tight bass
40 liters (1.41 cu. ft.) F - 3 = 41Hz / Punchy and dynamic bass
50 liters (1.77 cu. ft.) F - 3 = 40Hz / Deep and articulate bass

Once you know what your chasing listening wise you simply build your enclosure using volume calculators (http://www.the12volt...io/boxcalcs.asp)
and something like Google SketchUp to draw it up and get you cut list (http://www.sketchup....wnload/gsu.html)

Here is my current design just to give you an idea of what someone with no experience can do with these simple tools :-)
Posted ImagePosted Image
This is the resulting product:
Posted ImagePosted Image

Edited by Equilibrium1990, 06 August 2012 - 07:55 PM.


#3 kedgenz

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Posted 06 August 2012 - 10:07 PM

wat did you seal it with befor you painted the box

#4 Equilibrium1990

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Posted 06 August 2012 - 11:11 PM

Fiberglass resin :-)