Does my box need bracing?
 

The external dimensions are 12.5x12.5x12.5. My internal depth is 11".
My type r sub is 7.9" deep, being run off a mrdm605.

2 Questions:

1. will the subs back have a bit of play in it? How far should it move back? 1"?
2. if so then i have 2 inches to do my bracing if I need it. DO I NEED IT?? I was thinking using 1x2" wood, running making a plus symbol looking at it from the baffle...the vertical piece of wood attached to the back of the box at a few points and the horizontal one attached at three points: the vertical brace, and the two sides of my box..also thinking of adding a larger piece of wood that covers more surface area on the sides of the box connected to the horizontal brace.

Any suggestions for my brace design and is it necessary?

I'm not exactly clear how your box design is, but if you are suggesting using seperate chambers for each woofer in the same box, it's usually Ok, but not totally necessary. But if you're thinking about stacking two identical pieces of wood on top of each other, don't bother with it provided the board is 3/4in thick+.

Youre not suppose to use a perfect cube as a box. I would play with the numbers a bit and avoid the cube. Your box is small enough that it does not need bracing.

ok so no on bracing.. Would you recommend a 3 sided or 4 sided enclosure. Why are these better anyways? Just to relieve some of the torque at the mounting points?

What is a 3 sided enclosure? Or even 4 sided? It should have 6 sides. :oh:

Why is what better?

A pretty crazy enclosure! I'm sorry I was just making a cross section of the box. 3 sided= 5 sided=triangle enclose. 4sided=6 sided=the side mounting the sub is angled downwards(since a perfect cube is not great). Why are these enclosures better than a perfect cube?

Ok. You got me wrong.

There are no triangular enclosures. These are the ones you are refering to where one of the sides are angled up or down:
https://www.honda-acura.net/forums/a...id=49624&stc=1

When I say a cube, I mean a cube enclosure where ALL the sides are equal. So having a box that is 12.5 x 12.5 x 12.5 is a CUBE. You could easily change it to something like 11 x 11 x 13 (just throwing out numbers). Something like that is fine because not all the sides are equal.

Neither enclosure is "better" than the other. Enclosed space for the sub is enclosed space for the sub. I just read that it is not good to make a perfect cube.

nice drawing =)

actually, cubes have an effect on the sound. the shape of the box affects the deflection of the sound waves inside of it. what i've heard... is that cubes have an adverse effect. it didn't make a lot of sense to me, but since most boxes you see look similar to will'd incredible artistic expression up there, i assume it's true. who knows?