Strengthening box

[nick_19 1]

I can get my whole box to bounce up and down on the really low notes, and the woods vibrates a little more than I want.

My box has no internal bracing, and it has a double baffle. 33inches wide x 32 inches deep x 12.75 inches high

Now how can I strengthen this box without it taking up too much volume (minimum amount) and without having things poke out on the outside. I would use allthread, but that would cause me to have the end/bolt sticking out of the edge of the wood, which cannot happen because the box fits pretty tight.

I was thinking about fiberglassing or using wooden dowels. Any suggestions/advice? Thanks!!!!

Note: please don't get into arguments about strength and all that mess. Just make the box itself vibrate less

[shizzzon 461]

Strength is an illusion, you dont know what strength is.. bla bla bla, hehe

Just messin with ya.

Wooden dowels would work great if u can get ahold of some.

That or 2x4s

[nick_19 1]

Oh god you scared me for a second HA!

Ok that's what I was thinking. Dowels take up almost no space and are easy to put in.

Would glassing at least all the corners help noticeably do you think? Or would that be a waste of time/money?

And by noticeable, I mean to the ear... I'm not really a competitor.

[dem beats 1,223]

2x4's would be perfect, or steel beams. Metal would take up the least amount of space. Unless you Glassed and matted the whole thing and used rope, and even then it wouldn't only be minimal gains.

[nem 2,019]

Just out of curiosity would epoxy paint add any strength?

[ABXX49 20]

Just out of curiosity would epoxy paint add any strength?

Probably and unmeasurable amount.

My personal favorite way to add strength is to double baffle and triple baffle. I don't use a ton of cross bracing, which does help, but I will have a double baffle nearly everywhere. My boxes are pretty solid.

[dem beats 1,223]

Just out of curiosity would epoxy paint add any strength?

OH NOES!

the most dreaded resin WARZ!!1!!111!!!

I will answer this in a new way. It would be cheaper, and cost less to just brace properly, and perhaps use a different material for construction. There is a thread about this ongoing in this forum right now. An agreement cannot be made.

What we do know currently it that

#1 it doesn't matter if it will add or subtract strength for the applications we would like to use it for.

#2 it's not if it adds strength, but what the desired result is. It's not about holding more weight or increasing tensile strength.

If you are looking to stop box flex, bracing will be better in every category. If you want a shiny coating on the box Epoxy wins. Some people claim it helps in real world applications to achieve higher SPL scores. Nothing has been tested accurately and that empirical data put to theory though. At least not here

[AlanHall 6]

You can get some i think its 2inch dowl at home depot. would work good. i personally dont care for any internal bracing , but the dowls are round and most likely wont mess with airflow much. just be sure to predrill and glue them up good. I dont think resin or any other coating would help in your case to much if its flexing enough to bounce the enclosure. do you have enough room ro maybe do a layer of 1/2 inch to the outside?

[nick_19 1]

I really don't have any space... That is the problem really. It does have a double baffle on the top. Here is a pic of my previous enclosure w/o the top baffle on (basically the exact same enclosure).

I think I will just use about 8 dowel rods for bracing. I would double everything up, but I cannot due to space. And I was going to glass the whole inside, but that seems that I won't help as much for what I need to do. Here is a pic of the box plan.

It has a 45 in the port, but would it help to curve all the corners using glass, or should I just try it as an experiment, or do y'all think it'll be worth it?

[RobClay 20]

Threaded rods.

[AlanHall 6]

the way the enclosure is laid out i doubt 2 2x4 or like a 4inch wide piece of 3/4 on each side of the woofer would hurt much. Im not sure how you would use threaded rod with out the nut poking out the top and bottom, you cant have that if you dont have room for another layer on the bottom.I dont think the issue if in the corners . The bottom is a pretty large surface with no bracing. Id say brace the bottom to the baffle and leave it . or try to squeze a 2nd layer to the bottom.

[nick_19 1]

the way the enclosure is laid out i doubt 2 2x4 or like a 4inch wide piece of 3/4 on each side of the woofer would hurt much. Im not sure how you would use threaded rod with out the nut poking out the top and bottom, you cant have that if you dont have room for another layer on the bottom.I dont think the issue if in the corners . The bottom is a pretty large surface with no bracing. Id say brace the bottom to the baffle and leave it . or try to squeze a 2nd layer to the bottom.

Aight. Will do.

I'd love to use threaded rod, but as I (and AlanHall) said, I can't have it poke out of the bottom. I DEFINITELY do not have room for a layer on the bottom, so looks like I'm suck with bracing it. I'll try it and post up results!

[REVpuggie 23]

Threaded rods.

that indeed is a very efficient way to brace without taking up space !!

[nick_19 1]

Threaded rods.

that indeed is a very efficient way to brace without taking up space !!

I'd love to use threaded rod, but as I (and AlanHall) said, I can't have it poke out of the bottom.

[RobClay 20]

Thats what i get for reading

[nick_19 1]

Thats what i get for reading

Haha! Trust me allthread/threaded metal was my FIRST idea, but then the realization that it couldn't work occurred. Dowels should work I hope. I'm thinking about using 1 inch dowels and doing 8 braces. That would knock me down to 4.453 cu.ft., which really isn't far from 4.496 lol.

[Jay-C76 333]

On the edges and corners I'd use a 2x4 cut on 45's then mitered...

In the middle I'd use 2x4...

Do the math on the displacements of a 2x4, it's not that much.. (2x4 ~24"long = .111111cf3)

I know lumber isn't really to true measurements, so the number will actually be smaller.

Then when you rip them into edge/corner strips it's even less...

I always add a few extra on the cf3 just to compensate for the bracing.

[shizzzon 461]

2x4 is actually 1.5x4 so take it like that.

And Jay, where the db numbers at? , hehe

Are u gonna wait until slamology?

[nick_19 1]

On the edges and corners I'd use a 2x4 cut on 45's then mitered...

In the middle I'd use 2x4...

Do the math on the displacements of a 2x4, it's not that much.. (2x4 ~24"long = .111111cf3)

I know lumber isn't really to true measurements, so the number will actually be smaller.

Then when you rip them into edge/corner strips it's even less...

I always add a few extra on the cf3 just to compensate for the bracing.

Yeah I do too. Outta curiosity, why would you recommend 1 or 2 2x4's as opposed to 8 1 inch dowels?

[Adrian_D 520]

Threaded rods.

that indeed is a very efficient way to brace without taking up space !!

I'd love to use threaded rod, but as I (and AlanHall) said, I can't have it poke out of the bottom.

Easy fix for that.

Cut a hold bigger than the diameter of the nut and on the inside of the box attach a small piece of mdf over the hole. The piece of mdf is screwed to the panel you want to brace and it also holds the threaded rod. Nothing sticks out but you loose a tiny bit of airspace. Less than an mdf cross-brace.

A 2x4 takes up quite some space...

[shizzzon 461]

wow, that's a great idea. Be sure to use plenty of sealant. The airspace lost would be so minimal, it's not even worth calculating. Or if u plan on using multiple runs of rod, like 6 or more, just take ~0.3 cubes of airspace out of the box.

[Jay-C76 333]

Dowl is made from a different wood than a standard 2x4...

Most 2x4's are made from pine (yellow/white)

Dowls I think are made from.....(hmmm having a brain fart and can't recall) LOL

The pine is a little less rigid but easier to drill into and get good bites with screws.

[REVpuggie 23]

sorry for overseeing that post ... butt still, use your imagination it can be done without having stuff sticking out of the box

[AlanHall 6]

i dont think i would use all those dowls.. just a couple of the large diameter ones should be fine.ive had good luck with them or even just 2 2x4s, i dont think all the 45s in the corners will help your problem

[Jay-C76 333]

2x4 is actually 1.5x4 so take it like that.

And Jay, where the db numbers at? , hehe

Are u gonna wait until slamology?

LOL....

No numbers as of yet...

I forgot to call around to the local idiots...I mean shops....LOL

I've been trying to save every penny I can, trying to get a new windshield..

If I can't get it in time, I may have to pass on Slamology....(bumber)

Maybe I could be a man whore! LMAO

The kids and ole' lady might have a thing to say about that...

Anyone have a spare windshield for a 05' Ranger laying around ?????