Cabinet bracing opinions, observations etc.?

[ViolenceOnTheRadio]

I just went overboard and built 2 massive cabinets 4x2x2 completely disregarding the math since the purpose is to house a plethora of tweeters and 2 aluminum cone 15's. Huge and loud for the sake of P.A. use.
I'm not sure about bracing though. So far I've conceived just adding a rib cage skeletal like structure before installing my insulation material. Here's a hard draft of the design.
[IMGDEAD]http://i56.tinypic.com/2woac0m.jpg[/IMGDEAD]
I'll likely add vertical beams to the rear/side corner seams as well.
I had thought about placing some cross beams horizontally but, really don't want to divide the sound waves. The weight is also crazy enough anyway. There is a 3 inch vent at the top and bottom of the speaker baffle. Does anyone have preferences for bracing their loud speakers?
I've seen a lot of really amazing designs as well as crude internal builds where several 2x4's are just bridged across and through the center of the cabinet. I'm avoiding braces that will create ducts and sound wave dividing and will only implement such if there's too much noise or boom.

 

[ViolenceOnTheRadio]

It had to be done!
[IMGDEAD]http://i54.tinypic.com/70uj2f.jpg[/IMGDEAD]

 

[bentoronto]

All kinds of different forces acting on the wider expanses of rectangular surfaces. Sealed boxes need the most attention - OK to make them a little leaky even if it drives your simulation program crazy!

One main force is like a balloon expanding. So run braces like from middle of the left side sheet to the middle of the right. One way is to take a length of electrical conduit pipe (rigid steel, light, cheap, available) and epoxy it in place on the two sides. Wood OK too.

One brace that way is much more effective that trying to rigidize with "ribs" to the plane surfaces.

 

[ViolenceOnTheRadio]

Ah yeah I hadn't really thought about it that way. The flexing and expanding from the gas compression. Ribs like I proposed would certainly make it tough as nails but a beam through the center would obviously be more effective in terms of added mass to performance ratio.

I had also conceived a plan to use angled boards at the top and bottom equal in width to the baffle and in depth to the cabinet when angled that would bounce the sound right out the ducts. I suppose I should got back to that concept and use a beam right through the center as well.
Then I'll have center flex bracing and directional architecture that braces the top and bottom from flexing.

 

[planet10]

I just went overboard and built 2 massive cabinets... Huge and loud for the sake of P.A. use...The weight is also crazy enough anyway..

How are these constructed? The grainy photo makes me think partical board. Are they actually for PA use & to be humped around?

Any enclosure this large will need bracing.

dave