When is bracing necessary?

[dan5505 10+ year member]

I hope this isn't a massive repost. I did a search and didn't come up with much. Does anyone have a generic answer to this?

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[rollerdj 10+ year member]

depending on what type / size of sub, what u are wanting to do with it, and the type of wood you are using, then yes. so the question is, what are u planning on doing?

 

[dan5505 10+ year member]

Im planning to port a 15" Fi Q to 32 Hz with 3.5 cubes. http://www.subwoofertools.com/forum/ported-box.asp?Ew=36&Eh=18&Dia=9&Xmax=27&Vd=.19&NumW=1&Vb=3.5&Fb=32&Qts=&Vas=&Fs=&CE=0

 

[rollerdj 10+ year member]

if u use some good 3/4" mdf i don't think u'll have to much of a problem. then again. the one i did that was allmost that size didn't give me any problems.

 

[dan5505 10+ year member]

ok, cool. What sort of problems could arise? I'm guessin that the material could flex under stress causing a change in volume?

 

[rollerdj 10+ year member]

that, could weaken the joints if not put together right. the one thing i would suggest is doing a double baffle so the screws for the sub won't break loss. if you are going for shear SPL or some kinda bass race, then u might wanna add a little. but for daily, u'll never know a differnce.

 

[dan5505 10+ year member]

by double baffle, do you mean a double layer of mdf? Here is how far i am on the design so far.

 

[Punk In Drublic 10+ year member]

I don't think you'll need that much port area but I'm not certain.. someone?

 

[rollerdj 10+ year member]

don't know about the port area as there is no measurements there. a double baffle is IMO eather 2 sheets of mdf up front were ther sub is, or a extra ring around the cut out for the sub is so that the screws go though 2 layers instead of 1.

 

[dan5505 10+ year member]

Sorry about the dimensions, most of them should be on this page:

http://www.subwoofertools.com/forum/ported-box.asp?Ew=36&Eh=18&Dia=9&Xmax=27&Vd=.19&NumW=1&Vb=3.5&Fb=32&Qts=&Vas=&Fs=&CE=0

I was guna put it into winisd and see what happened. so far this whole thing is based off of that link.

 

[rollerdj 10+ year member]

at 32 sould do fine. like i said, i would double baffle it. anything over 12" IMO (unless a really beefy sub) should get double baffled.

 

[rollerdj 10+ year member]

are u gonna build it or have someone else do it for u?

 

[dan5505 10+ year member]

ohh no, ill definitely build it myself. Ill do the double baffle also. thanks for that idea.

 

[rollerdj 10+ year member]

welcome. lets see some pics afterward too. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[IgnoreMe 5,000+ posts]

you wont need any bracing for that box bro.

cool thing about slot port boxes (versus aero ports) is that the port (if long enough, like in your picture) acts as a brace. no need for a double baffle on that box either