custom fiberglass PORTED enclosure

[req 5,000+ posts]

good luck with that, i cant wait to see the result. u gona paint the box? if so GOOD LUCK with that as well, i give u mad props for trying this.

it shouldnt be that hard //content.invisioncic.com/y282845/emoticons/offwall.gif.29a91b9b265d47af4b8e33fc5b558d18.gif

but if this is gonna work, i still need to know if 2x5x2 (length x width x height) is 20 cubic inches - and how do i know if 20 cubic inches is the correct volume for a 1.2 cubic foot box @ 37 hertz?

if somone would point me in the right direction or give me a little more help in this area, ill get building asap.

//content.invisioncic.com/y282845/emoticons/veryexcited.gif.c26a15f316d23068607f36ddacd7a7ab.gif

 

[Nikuk 5,000+ posts]

it shouldnt be that hard //content.invisioncic.com/y282845/emoticons/offwall.gif.29a91b9b265d47af4b8e33fc5b558d18.gif
but if this is gonna work, i still need to know if 2x5x2 (length x width x height) is 20 cubic inches - and how do i know if 20 cubic inches is the correct volume for a 1.2 cubic foot box @ 37 hertz?

if somone would point me in the right direction or give me a little more help in this area, ill get building asap.

//content.invisioncic.com/y282845/emoticons/veryexcited.gif.c26a15f316d23068607f36ddacd7a7ab.gif

okay port area is Square inches as its only 2 dimensional. LxW of the opening of the port. The depth of the port then decides tuning.

Port Area = sq in, effects xmax, affects port noise.

Port Depth = how far into enclosure, decides tuning freq for a given port area.

LxW of opening = port area

LxWxD of entire port = cubic volume or displacement.

I used 20sq in cause of this:

....id like to to be wide and short... like 10"~15" wide, 2~5" tall, and 10~15 deepl. anywhere close to those sizes are fine... smaller is fine too.

Using your smallest choices i got 20 sq in.i would actually recommend a lil smaller port area for that volume (depending on what driver you're using) for xmax reasons possibly.

but you said its 29.08" deep. how wide and tall? you said all i gotta do is get 20cuin of internal volume for the port and it will be 37hz for 1.2cube box(after displacements)?you said i need 20 cubic inches for 37hz. those (internal) dimensions equal 20cuin of port area, correct? am i wrong with this?

20 sq in of port = 2x10, 5x4, 6.666x3 or whatever you want. could be a triangle port or a hexagon or whatever kind of polygon you make it to = 20 sq in.

Yes, with the formula i posted earlier for 1.2 net (after port & driver displacement) the tuning is 37.00etc hz with 20sq in of port at a lentgh of 29.08".

Again, those are internal dimensions of the port. I would try to use glass to keep the walls thin to save you some vB, also the usuals port rules apply (keeping both ends away from obstruction...).

If you want to change the port area i can recalc for you. I usually dont have much else to do all day while i'm here. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Nikuk 5,000+ posts]

Gross Vol:1.627

Net Vol: 1.200

Port: Width 10

Port Freq: 37.0003 Height 2

Cross Sec:20 Depth 29.08

SSF Freq: 27.75025856 Volume 0.336574074

what i have in excel using the JL calcs

Frequency=0.159*(((AV*(1.84*10^8))/(Vb*(LV + 0.823*(AV^0.5))))^0.5)

 

[req 5,000+ posts]

okay port area is Square inches as its only 2 dimensional. LxW of the opening of the port. The depth of the port then decides tuning.Port Area = sq in, effects xmax, affects port noise.

Port Depth = how far into enclosure, decides tuning freq for a given port area.

LxW of opening = port area

LxWxD of entire port = cubic volume or displacement.

I used 20sq in cause of this: Using your smallest choices i got 20 sq in.

i would actually recommend a lil smaller port area for that volume (depending on what driver you're using) for xmax reasons possibly.

20 sq in of port = 2x10, 5x4, 6.666x3 or whatever you want. could be a triangle port or a hexagon or whatever kind of polygon you make it to = 20 sq in.

Yes, with the formula i posted earlier for 1.2 net (after port & driver displacement) the tuning is 37.00etc hz with 20sq in of port at a lentgh of 29.08".

Again, those are internal dimensions of the port. I would try to use glass to keep the walls thin to save you some vB, also the usuals port rules apply (keeping both ends away from obstruction...).

If you want to change the port area i can recalc for you. I usually dont have much else to do all day while i'm here. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

what i have in excel using the JL calcs Frequency=0.159*(((AV*(1.84*10^8))/(Vb*(LV + 0.823*(AV^0.5))))^0.5)

fan-****ing-tastic =D

well that cleared up alot of stuff

//content.invisioncic.com/y282845/emoticons/smash.gif.499e08a4a35ffaf54f4c8194fb8fe8ed.gif

this is what im going to make then.

Gross Vol:1.627

Net Vol: 1.200

Port: Width 10

Port Freq: 37.0003 Height 2

Cross Sec:20 Depth 29.08

SSF Freq: 27.75025856 Volume 0.336574074

10"x2"x29.08" = 27.75025856 cubic INCHES?

just to verify.

i might want it just a TAD shorter than 29 tho =P 30 inches is quite long - i could always make an L shape, but that would be a little more complicated //content.invisioncic.com/y282845/emoticons/censored.gif.f9ad8e7c6db58c5530c5a0a20a3b5baf.gif

 

[Nikuk 5,000+ posts]

fan-****ing-tastic =Dthis is what im going to make then.

Gross Vol:1.627

Net Vol: 1.200

Port:

Width 10 x Height 2 = Cross Sec: 20 sq inches

Depth 29.08

Port Freq: 37.0003

Cross Sec: 20 sq inches x Depth 29.08 = Volume 0.337 cu. FT.

^^ Corrected^^

1.627 Gross Vol - 0.09 cu FT (sub displacement) - 0.337 cu FT (port displacement not counting port walls) = 1.200 NET cu ft volume.

With that port would be tuned to 37.0003 HZ.

Okay?

Wanna shorter port? Use less port area.... gimme a minute....

 

[req 5,000+ posts]

sure thing buddy.

i am gonna set the port at a diagonal (see the first image there) cuz the box is gonna be in the corner... the entire box is gonna be shaped like this (profile)

....

.......

.........

....SUB.

.............

...............

..................

......PORT....

gonna have a nice curve, so the port can be nice and deep, but 30" is quite deep i think. maybe wider than 10" and more around 20" deep at most i think- it can be taller if you want as well. i just want it to be like low profile and wide.

=)

thanks for they help by the way. ill mention you in the thread i start regarding this enclosure worklog.

 

[Nikuk 5,000+ posts]

okay... shorter port.

Gross Vol:1.490

Net Vol: 1.201

Port:

Width 9 x Height 1.5 = Cross Sec: 13.5 sq inches

Depth 19.0805

Port Freq: 37.0000

Cross Sec: 13.5 sq inches x Depth 19.08 = Volume 0.149 cu. FT.

Okay?

You're going to have to let me know what you decide to build the port out of. the volume that the port walls take up WILL change your tuning slightly. I.E.- if you make the port on the floor of the enclosure and simply put up 2 sides & a top made of 3/4" mdf that will change your enclosure. It'll look like this:

Gross Vol:1.601

Net Vol: 1.200

Port:

Width 9 x Height 1.5 = Cross Sec: 13.5 sq inches

Depth 19.1000

Port Freq: 37.0002

Cross Sec: 13.5 sq inches x Depth 19.1 = Net Volume 0.149 cu. FT.

Total Port Volume: ((9+1.5=10.5)*(1.5+.75=2.25)*19.1)/1728=0.261133 cu. ft.

Hope I didn't lose you there.

gonna have a nice curve, so the port can be nice and deep, but 30" is quite deep i think. maybe wider than 10" and more around 20" deep at most i think- it can be taller if you want as well. i just want it to be like low profile and wide.

19 close enough?

i am gonna set the port at a diagonal (see the first image there) cuz the box is gonna be in the corner... the entire box is gonna be shaped like this (profile)...

thats cool. but remember that you want to have the port end at least 1.5" (port height) away from any walls. Meaning that the bottom depth of the enclosure needs to be at least 20.75" deep.

sorry for the crappy drawing, my tools here are limited.. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

_________

|...........|

|...........|

|.....____|

|___|port

BTW, the SE 10 displaces 0.14 cu. ft. right?? That is the sub you are using?

 

[req 5,000+ posts]

okay... shorter port.

Gross Vol:1.490

Net Vol: 1.201

Port Width: 9

Height: 1.5 = Cross Sec: 13.5 sq inches

Depth: 19.0805

Port Freq: 37.0000

Cross Sec: 13.5 sq inches x Depth 19.08 = Volume 0.149 cu. FT.



19 close enough?

yeap //content.invisioncic.com/y282845/emoticons/clap.gif.178cba2c538c68e720c727fcb024b19c.gif

thats cool. but remember that you want to have the port end at least 1.5" (port height) away from any walls. Meaning that the bottom depth of the enclosure needs to be at least 20.75" deep.

sorry for the crappy drawing, my tools here are limited.. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

_________

|...........|

|...........|

|.....____|

|___|port

BTW, the SE 10 displaces 0.14 cu. ft. right?? That is the sub you are using?

i sure am using the 10. and i already knew to put the port a few inches from the back wall and everything - but thanks for reminder.

as for the changing internal volume, the reason im making the port FIRST is so that i can fiberglass LARGER than the net volume inside the enclosure (including port displacements) and lower what the subs sees to 1.2 - hence only needing port dimensions.

so 9x1.5x19=13.5 sq inches for 1.2cube@37hz.

fantablious. anyone have anything else to say about this? anyone else think this sounds right?

 

[Nikuk 5,000+ posts]

yea, go big and backfill usually works fine.

This aint exactly what this thread started out as, but I hope it helps.

Lets see if it gets the Jmac ass-stamp of approval... for free....

 

[req 5,000+ posts]

AHWHJBAHAHHAHHAHAHHAHAH

i sure hope not //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

he is a goofy looking guy ^_^

ill try and put this base together tonite (if i can get my second kick carpeted and installed.