PDA

View Full Version : Box Prebuild



ssj2xxgotenxx
04-07-2006, 01:40 AM
Well springbreak is finally here, and I've decided to use my free time to build my box for my xxx. I'm pretty much using Moe Lester's plans for 2.1 CuFt @ 28hz, but I plan on adding a little flair. If you guys would be so kind to check my plans I'd greatly appreciate it.

Box Plans:

I plan on adding a single brace spaced throughout the box

http://i50.photobucket.com/albums/f340/ssj2xxgotenxx/boxplans.jpg

Here's the math for the brace at 1" thickness....

Displacement of entire "solid" brace is LxWxH:
(8.75)x(.75)x(13.5) Divided by 1728 = .051 CuFt

Displacement of "Hollow" part of brace is LxWxH:
(6.75)x(.75)x(11.5) Divided by 1728 = .033 CuFt

By taking the displacement of the entire brace and subtracting the hollow piece's displacement I get a net displacement of .009 Cuft, and since I'm using two I have a total displacement of .018 Cuft.

[2.31] total box volume - [.018] Brace - [.19] Driver displacement = 2.102 CuFt... Perfection =D plus room to spare for triangular corner bracing =D

JL12W7INAGS300
04-07-2006, 01:47 AM
looks pretty good, is the bracing really nessacary?

JL12W7INAGS300
04-07-2006, 01:48 AM
looks pretty good, is the bracing really nessacary?

Ingleside
04-07-2006, 02:20 AM
what kind of braces are thoes?

azbass
04-07-2006, 02:23 AM
looks pretty good, is the bracing really nessacary?

*slap* yes. unlike the boxes you build. his will be good.

Ingleside
04-07-2006, 02:28 AM
ohh, i think i get it...
are they going to be like a 'picture frame' type brace?

you could prob just use some 1" round dowel rods.

Aphix
04-07-2006, 02:46 AM
idk how sturdy that will be but if it doesnt work ive had good success with right angle triangles. Just use some liquid nails and stick em on the inside walls.

j3bus2k3
04-07-2006, 02:47 AM
I used the trianlge braces myself simply b/c I didnt trust myself enough to make a proper frame brace. for ~2.25ft^3 ish I wouldnt think bracing is a necesity.

Aphix
04-07-2006, 02:50 AM
Yeah thats going to be hard to make an exact square. And that slot is going to be a brace itself. But im not arguing with ya. Good luck on your project dude.

Pyro_By_Nature
04-07-2006, 03:50 AM
I wouldn't do the brace that way.I'll throw a 3-D up of how I'd do it tomorrow.

ssj2xxgotenxx
04-07-2006, 04:50 AM
Yeah thats going to be hard to make an exact square. And that slot is going to be a brace itself. But im not arguing with ya. Good luck on your project dude.

No worries my uncle is a carpenter =D


I wouldn't do the brace that way.I'll throw a 3-D up of how I'd do it tomorrow.

I'd really appreciate the help. Quite the gentlemen =)

And yes it's going to be a picture frame type bracing. I don't think it's reall nessesary, but couldn't hurt. I also want to incorporate the rabbited edge like Bj's post.

ssj2xxgotenxx
04-07-2006, 06:16 AM
Drool.... Thats impressive straight cuts + Rounded edges. You're box has inspired me to move the sub off to the right and put a single brace in the middle.

Jordantyler
04-07-2006, 06:40 AM
http://img112.imageshack.us/img112/4853/picture0153bz.jpg (http://imageshack.us)

PV Audio
04-07-2006, 10:37 AM
Shelf bracing is not critical on an enclosure that small. For my HT sub, I did two interlocking shelf braces with 4" holes every inch or so.

ssj2xxgotenxx
04-07-2006, 06:21 PM
Well... I revised my plans significantly thanks to the input of your great folks. Especially Mountaineer Man, Death By Bass, and Jordantyler for helping me out with my design.

To the details, I've decided to get rid of the left brace closest to the port since the port doubles as a brace itself (As noted by Death By Bass). I've moved the subs mounting position to the right. By doing this, it allows me to put a single brace in the middle of the entire box. Since I have some extra airspace to work with. I'm going to go with Jordantyler's method of bracing with crossbeams in combination with the picture frame method. This is what it's going to look like:

http://i50.photobucket.com/albums/f340/ssj2xxgotenxx/boxplans2.jpg

Unfourtunatly, there might be some problems with my modifications. This topic was brought up in another thread so check it out.


Here are two examples of ported boxes....

First one...in this box the port divides the box in half...thus like nG said giving the air an "option" on where to travel. which isnt good.

http://i31.photobucket.com/albums/c393/chevyaudio/BlakeBox1.jpg

Second box...in this box the air has only one path, that is to exit the box out of the port...

http://i31.photobucket.com/albums/c393/chevyaudio/Blakesfinalbox.jpg

The problem that I think will happen is this:

http://i50.photobucket.com/albums/f340/ssj2xxgotenxx/AitProb.jpg

Im afraid my design will have two directions of airflow(Wavy arrows represent airflow)... which is bad according to chevyaudio.

Am I just thinking about it too much, or is it an okay design?

Aphix
04-07-2006, 06:33 PM
Hey death by bass. Where the hell do they sell those subs you got in your avatar? lol I want one!

ssj2xxgotenxx
04-07-2006, 08:24 PM
Any input on the airflow problem?

New Math:

Displacement of entire "solid" brace is LxWxH:
(8.75)x(.75)x(13.5) Divided by 1728 = .051 CuFt

Displacement of "Hollow" squares:

(2.86)x(.75)x(5.25) Divided by 1728 x 4 pieces = .026 CuFt

Subtract "Solid - Hollow" and you get a total net displacement = .025 CuFt

[2.31] total box volume - [.025] Brace - [.19] Driver displacement = 2.095 CuFt... Near Perfection =D

http://i50.photobucket.com/albums/f340/ssj2xxgotenxx/Brace.jpg

PV Audio
04-09-2006, 06:00 PM
It should be fine bro, just make sure that you brace STRONGLY. A smaller brace that is done well is always better than something larger that is done weakly. If that doesn't make sense, consider using smaller braces that are stronger versus one large brace that can flex.