best way to brace

[Lakota 5,000+ posts]

I'm not trying to start a pissing contest butNO it's not..

rod bracing does nothing to stop other parts of the pannel

from vibarating..I used metal rod bracing in the past and

a propper wood braced box is much stiffer all around

I say this because of its size and tensile strength. Threaded rod can take quite a load before it will be pulled apart; quite a bit more than wood for its size. Wood can split, but nothing will ever happen to the rod. Another great thing is that it takes up much less volume than wood so that there wouldn't be as much turbulence. Given a wooden dowel the same size as threaded rod, the dowel has no chance.

I'm not trying to argue with you. Sorry if I came off that way. I'd just contributing what I know to the thread through my experience.

 

[PSturmer 10+ year member]

I'm not trying to start a pissing contest butNO it's not..

rod bracing does nothing to stop other parts of the pannel

from vibarating..I used metal rod bracing in the past and

a propper wood braced box is much stiffer all around

properly using threading rods and effectively halving a panel will be better than double layering a panel. sometimes rods will not because of the design, but when they can be used in the place of double layering it will save money and be better for vibrations. this is simple college physics.

 

[tommyk90 5,000+ posts]

I'm not trying to start a pissing contest butNO it's not..

rod bracing does nothing to stop other parts of the pannel

from vibarating..I used metal rod bracing in the past and

a propper wood braced box is much stiffer all around

I'd have to disagree with you.

Threaded rod makes an excellent brace, much better than a wooden dowel used in the same application.

While doubling up the panels would be the better option, having a double layered box would be extremely heavy and impractical in most applications.

I used threaded rod in my SPL enclosure to stop it from flexing, and it does so quite well. Double layering was not an option because of space concerns.

 

[GSRswapandslow 10+ year member]

i think he's talking about the bracing HE did in his pics....NOT just using wooden dowels. of course they're not as strong...that was never argued.

 

[tommyk90 5,000+ posts]

i think he's talking about the bracing HE did in his pics....NOT just using wooden dowels. of course they're not as strong...that was never argued.

Well, he has to clarify.

I do not consider "wood bracing" and a double layer box as the same thing.

 

[THUMPPER 10+ year member]

metal rods are high in tensile strength and they will stop the pannel

from flexing at point zero..

for example

take a coin and set it on an enclosure right by the location

of the metal rod...it will stay put..move the coin a small distance

from the location of the metal rod and the coin will vibarate

around or bounce...

with the proper wood bracing running down the entire pannel

in the right places

the whole pannel is protected from vibarating and the coin will

stay put where ever it is placed

the coin test is a really good way to test an enclosure for

vibarating or flexing pannels

if there is enough preasure to split or crack good wood bracing

the box will most likely blow apart anyways...

that would be cool to see happen

 

[tommyk90 5,000+ posts]

metal rods are high in tensile strength and they will stop the pannelfrom flexing at point zero..

for example

take a coin and set it on an enclosure right by the location

of the metal rod...it will stay put..move the coin a small distance

from the location of the metal rod and the coin will vibarate

around or bounce...

with the proper wood bracing running down the entire pannel

in the right places

the whole pannel is protected from vibarating and the coin will

stay put where ever it is placed

the coin test is a really good way to test an enclosure for

vibarating or flexing pannels

if there is enough preasure to split or crack good wood bracing

the box will most likely blow apart anyways...

that would be cool to see happen

Also, just an FYI, sometimes for SPL the box likes to flex. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

For daily driving I obviously wouldn't recommend that, but for maximum SPL it's best to test before and after bracing. While you may think that your internal braces do not cause turbulence because of their placement, I can say with the utmost confidence that your braces hurt airflow. Is it enough to notice a change in sound? Probably not. But its definitely not the most efficient way of bracing.

If at all possible I'll recommend people to double up on large panels, but if thats impossible then threaded rod can satisfy most installs. Wood bracing can look better from the outside since threaded rod tends to make boxes look ugly. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[BrianChia 10+ year member]

hazardous0388 is totally right. Keep your bracing via the air flow, tie in the walls, and 45 the corners. The better the flow, the better the bass.

Hope this has helped you.

what kind of plywood are you using on the box?

 

[Lakota 5,000+ posts]

You generally don't need to brace at the walls. That should already be a strong spot in the box.

 

[djman37 5,000+ posts]

brace all three axis, however you wish. Double baffling is a serious increase in weight and I'd only do that on the sub mounting panel. No area larger than 12x12 w/o a bracing point either. Your box should have a very 'high' pitch when knocked on...like concrete.

How you brace it isn't as important as doing the bracing; 'window pane', pieces, or threaded rod all work.

There are good pics on this forum of bracing...I'll look if I have a free minute today.

 

[jdc753 10+ year member]

brace all three axis, however you wish. Double baffling is a serious increase in weight and I'd only do that on the sub mounting panel. No area larger than 12x12 w/o a bracing point either. Your box should have a very 'high' pitch when knocked on...like concrete.How you brace it isn't as important as doing the bracing; 'window pane', pieces, or threaded rod all work.

There are good pics on this forum of bracing...I'll look if I have a free minute today.

I would go with this "window pane" method or double walls over threaded rod, but of course these all take up either air space and/or weight vs the rod. I just don't agree that the rod effectively Halves a panel. I can only see the rod having an area of influence on the panel according to the size of the rod and the tension placed in the rod. Do you guys who use rod put a turnbuckle in the middle so you can add some tension to the rod? Probably never happens but I would think it would be best as the rod is only good in tensile strength and not compressive strength, so you would have to place enough pre-tension on the rod iself so that it wouldn't go into a compression situation rendering it relatively useless.

EDIT: I can see the window pane method effectively Halving the panel as it is a solid cut across the weak axis of the panel.

 

[JDBuilder 10+ year member]

what kind of plywood are you using on the box?

It is a product called perfecta. It is a UL-MDF with a hardwood laminate finish. Strong, light, and super sound quality.

 

[Lakota 5,000+ posts]

I would go with this "window pane" method or double walls over threaded rod. can only see the rod having an area of influence on the panel according to the size of the rod and the tension placed in the rod. Do you guys who use rod put a turnbuckle in the middle so you can add some tension to the rod? Probably never happens but I would think it would be best as the rod is only good in tensile strength and not compressive strength, so you would have to place enough pre-tension on the rod iself so that it wouldn't go into a compression situation rendering it relatively useless.

With rod you can use washers on each side of the panel so that the pressure is distributed over a larger area. If Under enough tension the rod shouldn't flex side to side. If it does, either the rod is too thin or the box has some build quality issues (i.e. panels not thick enough and the box has too much flex w/o bracing). A properly built box should not have much flex without the bracing; bracing should be added to help. Rod can resemble window pane bracing (running rod in all 3 dimensions), do the same job, and save volume. I don't understand how other methods can be superior when they don't do as good of a job and take up more volume? The only true downside that I see to threaded rod is that it's not pretty.

 

[BrianChia 10+ year member]

It is a product called perfecta. It is a UL-MDF with a hardwood laminate finish. Strong, light, and super sound quality.

Thanks, it looks beautiful, as does your box. I'm assuming it takes a dark stain quite nicely? It seems like it would be perfect for home audio.

If you don't mind me asking, how much does it cost and do you have to special order it?