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View Full Version : Box Design, let me know if i should change anything!



Supergumby5000
12-31-2006, 01:58 PM
Well here is my enclosure design for two 15" type-R's. Its two separate 3.5cu ft enclosures combined into one box, each tuned to 33hz. If you guys think i should make any changes, anything, let me know!

For those who dont know the program, its showing a top, isometric (3D), front, and side view of the enclosure

http://img451.imageshack.us/img451/8912/boxwj7.jpg (http://imageshack.us)

Supergumby5000
12-31-2006, 02:02 PM
oh and dimensions are 41" across, 32.25" depth, and 17.75" height

PV Audio
12-31-2006, 02:03 PM
Dimensions of the port?

Supergumby5000
12-31-2006, 02:05 PM
Port Width: 3.25 inches
Port Area: 61.75 Square Inches
Port Length: 37.25 inches

PV Audio
12-31-2006, 02:09 PM
That seems to be right, but I didn't check it thoroughly. What'd you use to design it?

Supergumby5000
12-31-2006, 02:09 PM
also, there is one error in the drawing. the two middle pieces that separate the two enclosures dont extend all the way out to be flush with the port side of the box, they will be when its build tho, didnt notice that error til now

Supergumby5000
12-31-2006, 02:11 PM
well, i referred to this for the size of the enclosure iw ould need for one sub:

http://www.subwoofertools.com/forum/ported-box.asp?Ew=17&Eh=20.5&Dia=9&Xmax=20.5&Vd=.123&NumW=1&Vb=3.5&Fb=33&Qts=&Vas=&Fs=&CE=0

After i looked at that, i pretty much just kept those dimensions of the box, but combined two of them side by side to create a dual setup. I also added .75" to the top of the box to strengthen where the subs will be mounted.

Supergumby5000
12-31-2006, 02:12 PM
added .75" externally. didnt change the internal volume

PV Audio
12-31-2006, 02:14 PM
Oh. In that case, gimme a minute. I've had some bad luck with that calculator's accuracy.

PV Audio
12-31-2006, 02:16 PM
Okay, I'm getting 29.7 hz. Someone check my work.

Supergumby5000
12-31-2006, 02:21 PM
hmm bummer heh. any suggestions and how i would get this up to 33hz? i can make the depth of the box bigger (not height or length) or do whatever to the port.

PV Audio
12-31-2006, 02:26 PM
But also, for those dimensions I'm getting 3.7 cubes, not 3.5. If it were 3.5...

No, that'd still be ~30-31hz. I dunno, you can't really go wrong with tuning lower and having decent volume as it is. Just be conservative with the gain so that your risk of bottoming out is lessened, and you should be alright. I still want someone to check my math though.

Supergumby5000
12-31-2006, 02:27 PM
man, that website *****, lol

billabongcr
12-31-2006, 02:31 PM
phuck autocad..hated that class..

Supergumby5000
12-31-2006, 02:32 PM
phuck autocad..hated that class..

yeah i dont prefer it. would rather use rhino but i dont have it installed on my new computer atm, and im sending in the primary HD for an RMA :-/

Well, guess its back to the drawing board.

billabongcr
12-31-2006, 02:33 PM
it took me like 4 days to learn how to draw a line

PV Audio
12-31-2006, 02:42 PM
Rhinoceros is far better for this kind of work, and SketchUp is even better for rhino for rectangles. However, for fiberglass mockups, good God, Rhino can't be beat.

Supergumby5000
12-31-2006, 02:45 PM
PV audio so you said that box design is about 3.7 cubes at around 30hz? i dont know much about this box building hehe. i'll have to give it a whirl a few times and see if i can figure out how to get it 3.5 at 32.

PV Audio
12-31-2006, 02:51 PM
Like I said, that's what I'm getting over here, but there really isn't any way to get 3.5 cubes and that tuning with that port length. Even by on paper it doesn't work out right.

PV Audio
12-31-2006, 02:54 PM
Just redid my work, and got 30.2 hz. I dunno man, if I were you, I'd just keep it.

Supergumby5000
12-31-2006, 02:57 PM
ya think so? how much of a difference will it make?

PV Audio
12-31-2006, 02:59 PM
It'll be lower, but your av isn't makin my **** get lower at all :D

Supergumby5000
12-31-2006, 03:02 PM
It'll be lower, but your av isn't makin my **** get lower at all :D

lol. I dont mind the area of the box considering the room for it, but i dont want to be losing any high end. I see a lotta people with type R's tune between 32-34hz.

Supergumby5000
12-31-2006, 03:13 PM
if i kept the 3.7 cubes per sub, how much would i have to add to the port length to get it to at least 32 hz? or cani even do that?

PV Audio
12-31-2006, 03:23 PM
You wouldn't, making it longer makes the tuning lower. Making it shorter raises tuning, but also raises Vb meaning that the tuning runs on a kind of parabolic curve where the more you take off, the higher it gets, but it will eventually get lower.

If that makes no sense, then pay me no attention :)

Supergumby5000
12-31-2006, 05:49 PM
You wouldn't, making it longer makes the tuning lower. Making it shorter raises tuning, but also raises Vb meaning that the tuning runs on a kind of parabolic curve where the more you take off, the higher it gets, but it will eventually get lower.

If that makes no sense, then pay me no attention :)

heh i understand. Maybe i'll keep it who knows. I'll keep the plan but i might get one built for me just to settle all of it.

theothermike
12-31-2006, 06:03 PM
3.7 @ 30 per sub = very nice.

Keep it.

Good design not worth changing

Supergumby5000
12-31-2006, 07:49 PM
i wont be losing anything tuning that little bit extra lower will i? prolly a dumb question, but this will be my first ported box heh.

PV Audio
12-31-2006, 08:52 PM
Not really, like I said, it'll be a little bit lower and for a 15 you are usually looking for lows anyway :)

theothermike
12-31-2006, 09:03 PM
30 - 33 not a huge diff.

But i think it will actually help bring some more lows to you :-).

I think ill actually change my tuning from 28 to 30 on my box for my 12" fi q.