What makes a subwoofer box?

Question

I am making a sub box for 2 12 inch alpine SWE-1242 woofers. i have some quick questions concerning the enclosure i am making.

-The manufacturer states that the volume of a box for 1 speaker should be about 1.7 cubic feet. does this mean i just double this volume for 2 speakers?

-Is there a noticeable difference if i use .5 inch mdf or .75 inch mdf?

-if i get the volume to the correct cubic feet, is there anything else i have to do? like a specific length or width, or is volume the only thing that matters?

-do i need to put a divider between the speakers, or can i just stick them both in the same box?

thank you

Answer 1

If you have two of these subs then you will want to make an enclosure that has two chambers that are 1.7 cubic foot each.  That also answers your last question of having a divider.  

Depending on how powerful your subs are will determine how strong the enclosure needs to be.  Usually 3/4" MDF is the lowest I would recommend but you can use 1/2" "if" you build it properly.  What I mean by that is that you use internal bracing and make sure all the joints are secure.  

The key is to eliminate any flexing in the material.  Flexing of the wood will mean a loss of output.  So make sure the enclosure is very strong and can handle the power from the sub.  3/4" MDF is not that much more then 1/2" so that may be something to consider as well.  Also, if you add internal bracing just make sure you account for it's displacement.

The shape of the enclosure really doesn't matter much.  The only real exception is for perfect cubes.  Perfect cubes are not recommended for an enclosure shape because they will likely cause standing waves.  So as long as you don't make a perfect cube you will be fine.

Good Luck!!!

Answer 2

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