PDA

View Full Version : Dimensions for Box



supa_c
06-26-2004, 05:09 AM
15(L)x48(W)x18(H) (external) for 2 brahama 15's. i can go higher if necessary but not wider.
tuned to 28hz(sq) or 35hz(spl) (brahama specs).
the adire site only lists specs for round ports.
i want a vented box but i dont know how to make vented boxes.
im a winisd pro noob so i cant really use the program.
any replys are appreciated since im going to build it in the next week. bcae1 wont help because its for 2 not 1 sub.

supa_c
06-26-2004, 04:08 PM
!!!bump!!!

Trixter
06-26-2004, 05:41 PM
Personally, I would do a slot port in between them. It looks nice and adds sopport for the box. WinISD is not that accurate of a program to figure out ports. I used to use loudspeakers101.com but the site is gone now. What you could do is divide the box into two chambers and go that route. This way you wouldn't have to mess around with anything. And if you want round ports you still could. (If you do I recommend Precision Ports from www.partsexpress.com. I used them for my Brahma and sounded awsome.) Or, if your set on a single chamber, you can use the formula on www.jlaudio.com turtorials under box building. Just find out how much port area Adire recommends for 1B-15 and X by 2. (I used 29sq" on my box that I have now. It's 3cu' tuned to 28Hz.)

supa_c
06-26-2004, 08:10 PM
Adire reccomends= for 1 15" Brahama.
3ft^ net @ 28hz.
16.5" x 16.5" x 20" (internal)
2 4" diag x 24" long ports.
I can do 16"(depth1) 19"(depth 2) x 48" x 20" external.
-------------------------^or just 16"^ ----------------------------------
I need a box for 2 brahamas. not 1.
i can go higher but not wider/deeper to make the box the right Fq. Adire says for ports not vents.
i would like to do vents if possible.
can any body give me the lengths of wood i would need to cut :help:

yamaha326
06-26-2004, 08:18 PM
just combine the diminsions

supa_c
06-26-2004, 08:50 PM
33 x 33 x 40 i cant do. only 16x 48 x 22. MAX!
what can i do for tuning. it equals 7.99 cubic feet net.
i wont be able to see out my back window. if i go any higher.
http://www.adireaudio.com/Files/cut%20sheets/Brahma%20Sales%20Brochure.pdf what will i have to do for slot ports to make the spl box.(35 hz)
how long/ how wide?

supa_c
06-26-2004, 08:53 PM
sorry but i dont know how to make vented boxes:crap: . thats where im a noob in car audio.

supa_c
06-27-2004, 04:28 AM
O.K.am i makin sense now
my box will be 22(h)x48(w)x16(d).
it equals 7.99 cubic feet. <--- very very close to reccomended spec. (8 ft net)
i want to tune it to 35hz
how long/wide will my vent(s) be for this aplication. im thinkin of doing the vent in the middle for bracing. if not thats fine.
win isd messes me up and ive heard its not accurate.
any help is greatly appreciated. i know you guys have box building programs but i don't.
sorry for all the other crap i am learning by the min!
*update*
i used that jl port thingy and i just got very confused.

supa_c
06-27-2004, 04:20 PM
hello, anybody.
i just want to know how long/wide/tall my port will be for a 22x48x16(external) box.
tuned to 35 hz.
can any body help me.

DBfan187
06-27-2004, 04:23 PM
need more space for the height. Should atleast make it 18"

supa_c
06-27-2004, 04:32 PM
22(h) 48(w) 16(d). i cant go higher because i wont be abe to see out my back window. i can do 18"(d) if i really have to.
22x48x16=7.99^3. thats what adire reccomends for net volume.
http://www.adireaudio.com/Files/cut%20sheets/Brahma%20Sales%20Brochure.pdf
but what will the port dimensions be.:crap: no body wants to help.

supa_c
06-28-2004, 03:04 AM
!bump!
10 chars

Trixter
06-28-2004, 04:59 PM
Ok, you can do a slot port in between the subs that is 3" wide, 20.5" tall, and 8.5" long. This will give you 35Hz. 14" long will give you 28Hz.

using the formula:
FS = .159 x sq.rt. [(AV (184 x 10^8)) / VB (LV + .823 x sq.rt AV)]

FS: freq.
AV: vent area
LV: vent length
VB: box vol. (in sq.")

35 = .159 x sq.rt [(61.5 x 84000000) / (12958.312 x 8 + 8.67)]

35 = .159 x sq.rt [(5166000000) / (12958.312 x 8 + 8.67)]

This formula has to be done twice. Do it once to find the port length. Then recalculate the displacement of it and subtract it from the VB. Do the formula again to find out the port length after port displacement.

35 = .159 x sq.rt [(5166000000) / (12289.312 x 8.5 + 8.67)]

supa_c
07-04-2004, 03:09 AM
well i built the box today. dang, it was so akward with a little table saw. hopefully it blasts my eardrums.
thanks trickster, for the port specs.
that formula is hard