AVS Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
4,347 Posts
Discussion Starter #1
Is there a way to determine optimal bracing structure, wood thickness, how much volume should be present between bracing structures, etc?


I am gonna be kinda close on my boxes in terms of having adequate recommended volume for sealed boxes. I want to use as little space as possible for bracing for that reason.


My boxes are very tall in-walls. Dimensions are 9"x77"x21" approximately.


Trying to stay effective but simple... Not planning on finding a cnc router...
 

·
Registered
Joined
·
4,347 Posts
Discussion Starter #2



Would a design like this be sufficient? Looks pretty easy to do but uses a fair amount of volume...
 

·
Registered
Joined
·
4,347 Posts
Discussion Starter #4

Quote:
Originally Posted by Mrkazador  /t/1526766/optimizing-cabinet-bracing#post_24592973


You can use dowels for bracing. Front to back, side to side every 8" or so.

So that will have the necessary rigidity I guess, just wood glue them in?
 

·
Banned
Joined
·
15,491 Posts

Quote:
Originally Posted by blazar  /t/1526766/optimizing-cabinet-bracing#post_24592926


Is there a way to determine optimal bracing structure, wood thickness, how much volume should be present between bracing structures, etc..
Experience.
Quote:
You can use dowels for bracing. Front to back, side to side every 8" or so.
IME that's sufficient with 3/4 inch construction. Closer spacing will allow thinner panels. For instance, you'd get the same stiffness using 3/8" panels with the braces spaced at four inches as with 3/4" spaced at eight inches.
 

·
Registered
Joined
·
4,347 Posts
Discussion Starter #6
Just simply do a lattice inside the box, right?
 

·
Registered
Joined
·
7,989 Posts
The tricky part with dowels is glueing end grain. Gotta fit them into a forstner hole or something. Also making assembly tricky. That's where wider planks of plywood or MDF can be useful because you get more glue are on the end of the board, and in the case of MDF it isn't end grain.


Is this a sub or speaker?
 

·
Banned
Joined
·
15,491 Posts

Quote:
Originally Posted by blazar  /t/1526766/optimizing-cabinet-bracing#post_24593298


Just simply do a lattice inside the box, right?
Yes, but a three dimensional lattice, like this:



However, if the cab depth is shallow enough you may not need anything connecting the sides or the top and bottom.
 

·
Registered
Joined
·
4,347 Posts
Discussion Starter #9
It is for subwoofers, and yes the cabinet is pretty shallow.


Is the picture I posted of JL audio's inwall design a bad method?
 

·
Banned
Joined
·
15,491 Posts

Quote:
Originally Posted by blazar  /t/1526766/optimizing-cabinet-bracing#post_24593413


Is the picture I posted of JL audio's inwall design a bad method?
It wastes a lot of material with bracing on the panel face that doesn't actually do much, and I don't see any actual panel to panel braces.
 

·
Registered
Joined
·
4,347 Posts
Discussion Starter #11
That panel face bracing is strange, not sure what they were trying to do except perhaps make assembly streamlined
 

·
Premium Member
Joined
·
24,316 Posts

Quote:
Originally Posted by tuxedocivic  /t/1526766/optimizing-cabinet-bracing/0_50#post_24593358


The tricky part with dowels is glueing end grain.

Make the holes deep enough to get sufficient area around the circumference.
 

·
Registered
Joined
·
7,989 Posts
Well ya, but that's the tricky part. In 3/4" material that doesn't leave you much, and you have to align the dowel as you assemble the cabinet. It can be done, it's just not as easy as a wide piece of mdf/plywood.
 

·
Registered
Joined
·
4,347 Posts
Discussion Starter #14
I will likely mix some dowels in between some more typical bracing like in the picture i showed. I can easily make some holes in those braces for dowels which will make "setting" the dowels easier and more accurate.
 

·
Premium Member
Joined
·
24,316 Posts

Quote:
Originally Posted by tuxedocivic  /t/1526766/optimizing-cabinet-bracing/0_50#post_24596753


Well ya, but that's the tricky part. In 3/4" material that doesn't leave you much, and you have to align the dowel as you assemble the cabinet. It can be done, it's just not as easy as a wide piece of mdf/plywood.

It's easy if you pre-drill one hole to depth, and the opposite panel has a through-hole; then they can be done after the box is assembled.


Hey wait, didn't you do just exactly that with your boxes?
 

·
Registered
Joined
·
7,989 Posts
Yes I did do it that way. But then you're left with the dowel end to deal with. It will leave you with complications one way or the other. None insurmountable, but complicated none the less. And you need a forstner bit or a thick panel to drill into.
 

·
Registered
Joined
·
4,347 Posts
Discussion Starter #18
I have spade bits so it wont be a problem to prep some hiles for dowels if needed.
 

·
Registered
Joined
·
2,159 Posts
If a dowel is fit snugly into the box and just butt-glued in place at the end grain, is it really at such a high risk of the glue joint failing and the dowel coming loose? Seems like a good application for epoxy or a polyurethane glue.
 

·
Registered
Joined
·
7,989 Posts
Spade bits are fast, but usually the leading point is pretty long so I'm not sure you'd safely get a 1/2" in 3/4" material. I really don't think an end glue dowel is that strong. With vibration they'll pop off eventually. Epoxy or PL premium could work, but I'm not so sure it would be all that strong. Might be fine though.
 
1 - 20 of 20 Posts
Top